Configuring Authentication and User Agent

Overview

The OpenShift Container Platform master includes a built-in OAuth server. Developers and administrators obtain OAuth access tokens to authenticate themselves to the API.

As an administrator, you can configure OAuth using the master configuration file to specify an identity provider. It is a best practice to configure your identity provider during cluster installation, but you can configure it after installation.

OpenShift Container Platform user names containing /, :, and % are not supported.

The Deny All identity provider is used by default, which denies access for all user names and passwords. To allow access, you must choose a different identity provider and configure the master configuration file appropriately (located at /etc/origin/master/master-config.yaml by default).

When you run a master without a configuration file, the Allow All identity provider is used by default, which allows any non-empty user name and password to log in. This is useful for testing purposes. To use other identity providers, or to modify any token, grant, or session options, you must run the master from a configuration file.

Roles need to be assigned to administer the setup with an external user.

After making changes to an identity provider, you must restart the master services for the changes to take effect:

# master-restart api
# master-restart controllers

Identity provider parameters

There are four parameters common to all identity providers:

Parameter Description

Parameter	Description
`name`	The provider name is prefixed to provider user names to form an identity name.
`challenge`	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header. Not supported by all identity providers. To prevent cross-site request forgery (CSRF) attacks against browser clients Basic authentication challenges are only sent if a `X-CSRF-Token` header is present on the request. Clients that expect to receive Basic `WWW-Authenticate` challenges should set this header to a non-empty value.
`login`	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider. Not supported by all identity providers. If you want users to be sent to a branded page before being redirected to the identity provider’s login, then set `oauthConfig → alwaysShowProviderSelection: true` in the master configuration file. This provider selection page can be customized.
`mappingMethod`	Defines how new identities are mapped to users when they log in. Enter one of the following values: claim The default value. Provisions a user with the identity’s preferred user name. Fails if a user with that user name is already mapped to another identity. lookup Looks up an existing identity, user identity mapping, and user, but does not automatically provision users or identities. This allows cluster administrators to set up identities and users manually, or using an external process. Using this method requires you to manually provision users. See Manually Provisioning a User When Using the Lookup Mapping Method. generate Provisions a user with the identity’s preferred user name. If a user with the preferred user name is already mapped to an existing identity, a unique user name is generated. For example, `myuser2`. This method should not be used in combination with external processes that require exact matches between OpenShift Container Platform user names and identity provider user names, such as LDAP group sync. add Provisions a user with the identity’s preferred user name. If a user with that user name already exists, the identity is mapped to the existing user, adding to any existing identity mappings for the user. Required when multiple identity providers are configured that identify the same set of users and map to the same user names.

name

The provider name is prefixed to provider user names to form an identity name.

challenge

When true, unauthenticated token requests from non-web clients (like the CLI) are sent a WWW-Authenticate challenge header. Not supported by all identity providers.

To prevent cross-site request forgery (CSRF) attacks against browser clients Basic authentication challenges are only sent if a X-CSRF-Token header is present on the request. Clients that expect to receive Basic WWW-Authenticate challenges should set this header to a non-empty value.

login

When true, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider. Not supported by all identity providers.

If you want users to be sent to a branded page before being redirected to the identity provider’s login, then set oauthConfig → alwaysShowProviderSelection: true in the master configuration file. This provider selection page can be customized.

mappingMethod

Defines how new identities are mapped to users when they log in. Enter one of the following values:

claim: The default value. Provisions a user with the identity’s preferred user name. Fails if a user with that user name is already mapped to another identity.
lookup: Looks up an existing identity, user identity mapping, and user, but does not automatically provision users or identities. This allows cluster administrators to set up identities and users manually, or using an external process. Using this method requires you to manually provision users. See Manually Provisioning a User When Using the Lookup Mapping Method.
generate: Provisions a user with the identity’s preferred user name. If a user with the preferred user name is already mapped to an existing identity, a unique user name is generated. For example, myuser2. This method should not be used in combination with external processes that require exact matches between OpenShift Container Platform user names and identity provider user names, such as LDAP group sync.
add: Provisions a user with the identity’s preferred user name. If a user with that user name already exists, the identity is mapped to the existing user, adding to any existing identity mappings for the user. Required when multiple identity providers are configured that identify the same set of users and map to the same user names.

When adding or changing identity providers, you can map identities from the new provider to existing users by setting the mappingMethod parameter to add.

Configuring identity providers

OpenShift Container Platform does not support configuring multiple LDAP servers for the same identity provider. However, you can extend the basic authentication for more complex configurations such as LDAP failover.

You can use these parameters to define the identity provider during installation or after installation.

Configuring identity providers with Ansible

For initial cluster installations, the Deny All identity provider is configured by default, though it can be overriden during installation by configuring openshift_master_identity_providers parameter in the inventory file. Session options in the OAuth configuration are also configurable in the inventory file.

Example identity provider configuration with Ansible

# htpasswd auth
openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider'}]
# Defining htpasswd users
#openshift_master_htpasswd_users={'user1': '<pre-hashed password>', 'user2': '<pre-hashed password>'}
# or
#openshift_master_htpasswd_file=/etc/origin/master/htpasswd

# Allow all auth
#openshift_master_identity_providers=[{'name': 'allow_all', 'login': 'true', 'challenge': 'true', 'kind': 'AllowAllPasswordIdentityProvider'}]

# LDAP auth
#openshift_master_identity_providers=[{'name': 'my_ldap_provider', 'challenge': 'true', 'login': 'true', 'kind': 'LDAPPasswordIdentityProvider', 'attributes': {'id': ['dn'], 'email': ['mail'], 'name': ['cn'], 'preferredUsername': ['uid']}, 'bindDN': '', 'bindPassword': '', 'insecure': 'false', 'url': 'ldap://ldap.example.com:389/ou=users,dc=example,dc=com?uid'}]
# Configuring the ldap ca certificate (1)
#openshift_master_ldap_ca=<ca text>
# or
#openshift_master_ldap_ca_file=<path to local ca file to use> (2)

# Available variables for configuring certificates for other identity providers:
#openshift_master_openid_ca
#openshift_master_openid_ca_file (2)
#openshift_master_request_header_ca
#openshift_master_request_header_ca_file (2)

1 If you specified 'insecure': 'true' in the openshift_master_identity_providers parameter for only an LDAP identity provider, you can omit the CA certificate.

2 If you specify a file on the host you run the playbook on, its contents are copied to the /etc/origin/master/<identity_provider_name>_<identity_provider_type>_ca.crt file. The identity provider name is the value of the openshift_master_identity_providers parameter, ldap, openid, or request_header. If you do not specify the CA text or the path to the local CA file, you must place the CA certificate in this location. If you specify multiple identity providers, you must manually place the CA certificate for each provider in this location. You cannot change this location.

You can specify multiple identity providers. If you do, you must place the CA certificate for each identity provider in the /etc/origin/master/ directory. For example, you include the following providers in your openshift_master_identity_providers value:

openshift_master_identity_providers:
- name: foo
  provider:
    kind: OpenIDIdentityProvider
    ...
- name: bar
  provider:
    kind: OpenIDIdentityProvider
    ...
- name: baz
  provider:
    kind: RequestHeaderIdentityProvider
    ...

You must place the CA certificates for these identity providers in the following files:

/etc/origin/master/foo_openid_ca.crt
/etc/origin/master/bar_openid_ca.crt
/etc/origin/master/baz_requestheader_ca.crt

Configuring identity providers in the master configuration file

You can configure the master host for authentication using your desired identity provider by modifying the master configuration file.

Example 1. Example identity provider configuration in the master configuration file

...
oauthConfig:
  identityProviders:
  - name: htpasswd_auth
    challenge: true
    login: true
    mappingMethod: "claim"
...

When set to the default claim value, OAuth will fail if the identity is mapped to a previously-existing user name.

Manually provisioning a user when using the lookup mapping method

When using the lookup mapping method, user provisioning is done by an external system, via the API. Typically, identities are automatically mapped to users during login. The 'lookup' mapping method automatically disables this automatic mapping, which requires you to provision users manually.

For more information on identity objects, see the Identity user API obejct.

If you are using the lookup mapping method, use the following steps for each user after configuring the identity provider:

Create an OpenShift Container Platform User, if not created already:
```
$ oc create user <username>
```
For example, the following command creates a OpenShift Container Platform User bob:
```
$ oc create user bob
```
Create an OpenShift Container Platform Identity, if not created already. Use the name of the identity provider and the name that uniquely represents this identity in the scope of the identity provider:
```
$ oc create identity <identity-provider>:<user-id-from-identity-provider>
```
The <identity-provider> is the name of the identity provider in the master configuration, as shown in the appropriate identity provider section below.

For example, the following commands creates an Identity with identity provider ldap_provider and the identity provider user name bob_s.
```
$ oc create identity ldap_provider:bob_s
```

Create a user/identity mapping for the created user and identity:

$ oc create useridentitymapping <identity-provider>:<user-id-from-identity-provider> <username>

For example, the following command maps the identity to the user:

$ oc create useridentitymapping ldap_provider:bob_s bob

Allow all

Set AllowAllPasswordIdentityProvider in the identityProviders stanza to allow any non-empty user name and password to log in.

Example 2. Master configuration using AllowAllPasswordIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_allow_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: AllowAllPasswordIdentityProvider

1	This provider name is prefixed to provider user names to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.

Deny all

Set DenyAllPasswordIdentityProvider in the identityProviders stanza to deny access for all user names and passwords.

Example 3. Master configuration using DenyAllPasswordIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_deny_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: DenyAllPasswordIdentityProvider

1	This provider name is prefixed to provider user names to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.

HTPasswd

Set HTPasswdPasswordIdentityProvider in the identityProviders stanza to validate user names and passwords against a flat file generated using htpasswd.

The htpasswd utility is in the httpd-tools package:

# yum install httpd-tools

OpenShift Container Platform supports the Bcrypt, SHA-1, and MD5 cryptographic hash functions, and MD5 is the default for htpasswd. Plaintext, encrypted text, and other hash functions are not currently supported.

The flat file is reread if its modification time changes, without requiring a server restart.

Because the OpenShift Container Platform master API now runs as a static pod, you must create the HTPasswdPasswordIdentityProvider htpasswd file in /etc/origin/master/ so it can be read by the container.

To use the htpasswd command:

To create a flat file with a user name and hashed password, run:

$ htpasswd -c /etc/origin/master/htpasswd <user_name>

Then, enter and confirm a clear-text password for the user. The command generates a hashed version of the password.

For example:

htpasswd -c /etc/origin/master/htpasswd user1
New password:
Re-type new password:
Adding password for user user1

You can include the -b option to supply the password on the command line:

$ htpasswd -c -b <user_name> <password>

For example:

$ htpasswd -c -b file user1 MyPassword!
Adding password for user user1

To add or update a login to the file, run:

$ htpasswd /etc/origin/master/htpasswd <user_name>

To remove a login from the file, run:

$ htpasswd -D /etc/origin/master/htpasswd <user_name>

Example 4. Master configuration using HTPasswdPasswordIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_htpasswd_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: HTPasswdPasswordIdentityProvider
      file: /etc/origin/master/htpasswd (5)

1	This provider name is prefixed to provider user names to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	File generated using `htpasswd`.

Keystone

Keystone is an OpenStack project that provides identity, token, catalog, and policy services. You can integrate your OpenShift Container Platform cluster with Keystone to enable shared authentication with an OpenStack Keystone v3 server configured to store users in an internal database. This configuration allows users to log in to OpenShift Container Platform with their Keystone credentials.

You can configure the integration with Keystone so that the new OpenShift Container Platform users are based on either the Keystone user names or unique Keystone IDs. With both methods, users log in by entering their Keystone user name and password. Basing the OpenShift Container Platform users off of the Keystone ID is more secure. If you delete a Keystone user and create a new Keystone user with that user name, the new user might have access to the old user’s resources.

Configuring authentication on the master

If you have:

Already completed the installation of Openshift, then copy the /etc/origin/master/master-config.yaml file into a new directory; for example:
```
$ cd /etc/origin/master
$ mkdir keystoneconfig; cp master-config.yaml keystoneconfig
```

Not yet installed OpenShift Container Platform, then start the OpenShift Container Platform API server, specifying the hostname of the (future) OpenShift Container Platform master and a directory to store the configuration file created by the start command:

$ openshift start master --public-master=<apiserver> --write-config=<directory>

For example:

$ openshift start master --public-master=https://myapiserver.com:8443 --write-config=keystoneconfig

If you are installing with Ansible, then you must add the identityProvider configuration to the Ansible playbook. If you use the following steps to modify your configuration manually after installing with Ansible, then you will lose any modifications whenever you re-run the install tool or upgrade.

Edit the new keystoneconfig/master-config.yaml file’s identityProviders stanza, and copy the example KeystonePasswordIdentityProvider configuration and paste it to replace the existing stanza:

oauthConfig:
  ...
  identityProviders:
  - name: my_keystone_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: KeystonePasswordIdentityProvider
      domainName: default (5)
      url: http://keystone.example.com:5000 (6)
      ca: ca.pem (7)
      certFile: keystone.pem (8)
      keyFile: keystonekey.pem (9)
      useKeystoneIdentity: false (10)

1	This provider name is prefixed to provider user names to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	Keystone domain name. In Keystone, usernames are domain-specific. Only a single domain is supported.
6	The URL to use to connect to the Keystone server (required).
7	Optional: Certificate bundle to use to validate server certificates for the configured URL.
8	Optional: Client certificate to present when making requests to the configured URL.
9	Key for the client certificate. Required if `certFile` is specified.
10	When `true`, indicates that user is authenticated by Keystone ID, not by Keystone user name. Set to `false` to authenticate by user name.

Make the following modifications to the identityProviders stanza:
1. Change the provider name ("my_keystone_provider") to match your Keystone server. This name is prefixed to provider user names to form an identity name.
2. If required, change mappingMethod to control how mappings are established between the provider’s identities and user objects.
3. Change the domainName to the domain name of your OpenStack Keystone server. In Keystone, user names are domain-specific. Only a single domain is supported.
4. Specify the url to use to connect to your OpenStack Keystone server.
5. Optionally, to authenticate users by Keystone ID instead of Keystone user name, set useKeystoneIdentity to true.
6. Optionally, change the ca to the certificate bundle to use in order to validate server certificates for the configured URL.
7. Optionally, change the certFile to the client certificate to present when making requests to the configured URL.
8. If certFile is specified, then you must change the keyFile to the key for the client certificate.
Save your changes and close the file.
Start the OpenShift Container Platform API server, specifying the configuration file you just modified:
```
$ openshift start master --config=<path/to/modified/config>/master-config.yaml
```

Once configured, any user logging in to the OpenShift Container Platform web console will be prompted to log in using their Keystone credentials.

Creating Users with Keystone Authentication

You do not create users in OpenShift Container Platform when integrating with an external authentication provider, such as, in this case, Keystone. Keystone is the system of record, meaning that users are defined in a Keystone database, and any user with a valid Keystone user name for the configured authentication server can log in.

To add a user to OpenShift Container Platform, the user must exist in the Keystone database, and if required you must create a new Keystone account for the user.

Verifying Users

Once one or more users have logged in, you can run oc get users to view a list of users and verify that users were created successfully:

Example 5. Output of oc get users command

$ oc get users
NAME         UID                                    FULL NAME   IDENTITIES
bobsmith     a0c1d95c-1cb5-11e6-a04a-002186a28631   Bob Smith   keystone:bobsmith (1)

1	Identities in OpenShift Container Platform are comprised of the identity provider name prefixed to the Keystone user name.

From here, you might want to learn how to manage user roles.

LDAP authentication

Set LDAPPasswordIdentityProvider in the identityProviders stanza to validate user names and passwords against an LDAPv3 server, using simple bind authentication.

If you require failover for your LDAP server, instead of following these steps, extend the basic authentication method by configuring SSSD for LDAP failover.

During authentication, the LDAP directory is searched for an entry that matches the provided user name. If a single unique match is found, a simple bind is attempted using the distinguished name (DN) of the entry plus the provided password.

These are the steps taken:

Generate a search filter by combining the attribute and filter in the configured url with the user-provided user name.
Search the directory using the generated filter. If the search does not return exactly one entry, deny access.
Attempt to bind to the LDAP server using the DN of the entry retrieved from the search, and the user-provided password.
If the bind is unsuccessful, deny access.
If the bind is successful, build an identity using the configured attributes as the identity, email address, display name, and preferred user name.

The configured url is an RFC 2255 URL, which specifies the LDAP host and search parameters to use. The syntax of the URL is:

ldap://host:port/basedn?attribute?scope?filter

For the above example:

URL Component Description

URL Component	Description
`ldap`	For regular LDAP, use the string `ldap`. For secure LDAP (LDAPS), use `ldaps` instead.
`host:port`	The name and port of the LDAP server. Defaults to `localhost:389` for ldap and `localhost:636` for LDAPS.
`basedn`	The DN of the branch of the directory where all searches should start from. At the very least, this must be the top of your directory tree, but it could also specify a subtree in the directory.
`attribute`	The attribute to search for. Although RFC 2255 allows a comma-separated list of attributes, only the first attribute will be used, no matter how many are provided. If no attributes are provided, the default is to use `uid`. It is recommended to choose an attribute that will be unique across all entries in the subtree you will be using.
`scope`	The scope of the search. Can be either `one` or `sub`. If the scope is not provided, the default is to use a scope of `sub`.
`filter`	A valid LDAP search filter. If not provided, defaults to `(objectClass=*)`

ldap

For regular LDAP, use the string ldap. For secure LDAP (LDAPS), use ldaps instead.

host:port

The name and port of the LDAP server. Defaults to localhost:389 for ldap and localhost:636 for LDAPS.

basedn

The DN of the branch of the directory where all searches should start from. At the very least, this must be the top of your directory tree, but it could also specify a subtree in the directory.

attribute

The attribute to search for. Although RFC 2255 allows a comma-separated list of attributes, only the first attribute will be used, no matter how many are provided. If no attributes are provided, the default is to use uid. It is recommended to choose an attribute that will be unique across all entries in the subtree you will be using.

scope

The scope of the search. Can be either one or sub. If the scope is not provided, the default is to use a scope of sub.

filter

A valid LDAP search filter. If not provided, defaults to (objectClass=*)

When doing searches, the attribute, filter, and provided user name are combined to create a search filter that looks like:

(&(<filter>)(<attribute>=<username>))

For example, consider a URL of:

ldap://ldap.example.com/o=Acme?cn?sub?(enabled=true)

When a client attempts to connect using a user name of bob, the resulting search filter will be (&(enabled=true)(cn=bob)).

If the LDAP directory requires authentication to search, specify a bindDN and bindPassword to use to perform the entry search.

Master configuration using LDAPPasswordIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: "my_ldap_provider" (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: LDAPPasswordIdentityProvider
      attributes:
        id: (5)
        - dn
        email: (6)
        - mail
        name: (7)
        - cn
        preferredUsername: (8)
        - uid
      bindDN: "" (9)
      bindPassword: "" (10)
      ca: my-ldap-ca-bundle.crt (11)
      insecure: false (12)
      url: "ldap://ldap.example.com/ou=users,dc=acme,dc=com?uid" (13)

1	This provider name is prefixed to the returned user ID to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	List of attributes to use as the identity. First non-empty attribute is used. At least one attribute is required. If none of the listed attribute have a value, authentication fails.
6	List of attributes to use as the email address. First non-empty attribute is used.
7	List of attributes to use as the display name. First non-empty attribute is used.
8	List of attributes to use as the preferred user name when provisioning a user for this identity. First non-empty attribute is used.
9	Optional DN to use to bind during the search phase.
10	Optional password to use to bind during the search phase. This value may also be provided in an environment variable, external file, or encrypted file.
11	Certificate bundle to use to validate server certificates for the configured URL. The contents of this file are copied to the */etc/origin/master/<identity_provider_name>_ldap_ca.crt* file. The identity provider name is the value of the `openshift_master_identity_providers` parameter. If you do not specify the CA text or the path to the local CA file, you must place the CA certificate in the `/etc/origin/master/` directory. If you specify multiple identity providers, you must manually place the CA certificate for each provider in the `/etc/origin/master/` directory. You cannot change this location. Defining the certificate bundle only applies if `insecure: false` is set in the inventory file.
12	When `true`, no TLS connection is made to the server. When `false`, `ldaps://` URLs connect using TLS, and `ldap://` URLs are upgraded to TLS.
13	An RFC 2255 URL which specifies the LDAP host and search parameters to use, as described above.

To whitelist users for an LDAP integration, use the lookup mapping method. Before a login from LDAP would be allowed, a cluster administrator must create an identity and user object for each LDAP user.

Basic authentication (remote)

Basic Authentication is a generic backend integration mechanism that allows users to log in to OpenShift Container Platform with credentials validated against a remote identity provider.

Because basic authentication is generic, you can use this identity provider for advanced authentication configurations. You can configure LDAP failover or use the containerized basic authentication repository as a starting point for another advanced remote basic authentication configuration.

Basic authentication must use an HTTPS connection to the remote server to prevent potential snooping of the user ID and password and man-in-the-middle attacks.

With BasicAuthPasswordIdentityProvider configured, users send their user name and password to OpenShift Container Platform, which then validates those credentials against a remote server by making a server-to-server request, passing the credentials as a Basic Auth header. This requires users to send their credentials to OpenShift Container Platform during login.

This only works for user name/password login mechanisms, and OpenShift Container Platform must be able to make network requests to the remote authentication server.

Set BasicAuthPasswordIdentityProvider in the identityProviders stanza to validate user names and passwords against a remote server using a server-to-server Basic authentication request. User names and passwords are validated against a remote URL that is protected by Basic authentication and returns JSON.

A 401 response indicates failed authentication.

A non-200 status, or the presence of a non-empty "error" key, indicates an error:

{"error":"Error message"}

A 200 status with a sub (subject) key indicates success:

{"sub":"userid"} (1)

1	The subject must be unique to the authenticated user and must not be able to be modified.

A successful response may optionally provide additional data, such as:

A display name using the name key. For example:
```
{"sub":"userid", "name": "User Name", ...}
```

An email address using the email key. For example:

{"sub":"userid", "email":"user@example.com", ...}

A preferred user name using the preferred_username key. This is useful when the unique, unchangeable subject is a database key or UID, and a more human-readable name exists. This is used as a hint when provisioning the OpenShift Container Platform user for the authenticated identity. For example:
```
{"sub":"014fbff9a07c", "preferred_username":"bob", ...}
```

Configuring authentication on the master

If you have:

Already completed the installation of Openshift, then copy the /etc/origin/master/master-config.yaml file into a new directory; for example:
```
$ mkdir basicauthconfig; cp master-config.yaml basicauthconfig
```

$ openshift start master --public-master=<apiserver> --write-config=<directory>

For example:

$ openshift start master --public-master=https://myapiserver.com:8443 --write-config=basicauthconfig

Edit the new master-config.yaml file’s identityProviders stanza, and copy the example BasicAuthPasswordIdentityProvider configuration and paste it to replace the existing stanza:

oauthConfig:
  ...
  identityProviders:
  - name: my_remote_basic_auth_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: BasicAuthPasswordIdentityProvider
      url: https://www.example.com/remote-idp (5)
      ca: /path/to/ca.file (6)
      certFile: /path/to/client.crt (7)
      keyFile: /path/to/client.key (8)

1	This provider name is prefixed to the returned user ID to form an identity name.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to a login page backed by this provider.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	URL accepting credentials in Basic authentication headers.
6	Optional: Certificate bundle to use to validate server certificates for the configured URL.
7	Optional: Client certificate to present when making requests to the configured URL.
8	Key for the client certificate. Required if `certFile` is specified.

Make the following modifications to the identityProviders stanza:

Set the provider name to something unique and relevant to your deployment. This name is prefixed to the returned user ID to form an identity name.
If required, set mappingMethod to control how mappings are established between the provider’s identities and user objects.
Specify the HTTPS url to use to connect to a server that accepts credentials in Basic authentication headers.
Optionally, set the ca to the certificate bundle to use in order to validate server certificates for the configured URL, or leave it empty to use the system-trusted roots.
Optionally, remove or set the certFile to the client certificate to present when making requests to the configured URL.
If certFile is specified, then you must set the keyFile to the key for the client certificate.

Save your changes and close the file.
Start the OpenShift Container Platform API server, specifying the configuration file you just modified:
```
$ openshift start master --config=<path/to/modified/config>/master-config.yaml
```

Once configured, any user logging in to the OpenShift Container Platform web console will be prompted to log in using their Basic authentication credentials.

Troubleshooting

The most common issue relates to network connectivity to the backend server. For simple debugging, run curl commands on the master. To test for a successful login, replace the <user> and <password> in the following example command with valid credentials. To test an invalid login, replace them with false credentials.

curl --cacert /path/to/ca.crt --cert /path/to/client.crt --key /path/to/client.key -u <user>:<password> -v https://www.example.com/remote-idp

Successful responses

A 200 status with a sub (subject) key indicates success:

{"sub":"userid"}

The subject must be unique to the authenticated user, and must not be able to be modified.

A successful response may optionally provide additional data, such as:

A display name using the name key:

{"sub":"userid", "name": "User Name", ...}

An email address using the email key:

{"sub":"userid", "email":"user@example.com", ...}

A preferred user name using the preferred_username key:
```
{"sub":"014fbff9a07c", "preferred_username":"bob", ...}
```
The preferred_username key is useful when the unique, unchangeable subject is a database key or UID, and a more human-readable name exists. This is used as a hint when provisioning the OpenShift Container Platform user for the authenticated identity.

Failed responses

A 401 response indicates failed authentication.
A non-200 status or the presence of a non-empty "error" key indicates an error: {"error":"Error message"}

Request header

Set RequestHeaderIdentityProvider in the identityProviders stanza to identify users from request header values, such as X-Remote-User. It is typically used in combination with an authenticating proxy, which sets the request header value. This is similar to how the remote user plug-in in OpenShift Enterprise 2 allowed administrators to provide Kerberos, LDAP, and many other forms of enterprise authentication.

You can also use the request header identity provider for advanced configurations such as the community-supported SAML authentication. Note that SAML authentication is not supported by Red Hat.

For users to authenticate using this identity provider, they must access https://<master>/oauth/authorize (and subpaths) via an authenticating proxy. To accomplish this, configure the OAuth server to redirect unauthenticated requests for OAuth tokens to the proxy endpoint that proxies to https://<master>/oauth/authorize.

To redirect unauthenticated requests from clients expecting browser-based login flows:

Set the login parameter to true.
Set the provider.loginURL parameter to the authenticating proxy URL that will authenticate interactive clients and then proxy the request to https://<master>/oauth/authorize.

To redirect unauthenticated requests from clients expecting WWW-Authenticate challenges:

Set the challenge parameter to true.
Set the provider.challengeURL parameter to the authenticating proxy URL that will authenticate clients expecting WWW-Authenticate challenges and then proxy the request to https://<master>/oauth/authorize.

The provider.challengeURL and provider.loginURL parameters can include the following tokens in the query portion of the URL:

${url} is replaced with the current URL, escaped to be safe in a query parameter.

For example: https://www.example.com/sso-login?then=${url}
${query} is replaced with the current query string, unescaped.

For example: https://www.example.com/auth-proxy/oauth/authorize?${query}

If you expect unauthenticated requests to reach the OAuth server, a clientCA parameter MUST be set for this identity provider, so that incoming requests are checked for a valid client certificate before the request’s headers are checked for a user name. Otherwise, any direct request to the OAuth server can impersonate any identity from this provider, merely by setting a request header.

Master configuration using RequestHeaderIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_request_header_provider (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: RequestHeaderIdentityProvider
      challengeURL: "https://www.example.com/challenging-proxy/oauth/authorize?${query}" (5)
      loginURL: "https://www.example.com/login-proxy/oauth/authorize?${query}" (6)
      clientCA: /path/to/client-ca.file (7)
      clientCommonNames: (8)
      - my-auth-proxy
      headers: (9)
      - X-Remote-User
      - SSO-User
      emailHeaders: (10)
      - X-Remote-User-Email
      nameHeaders: (11)
      - X-Remote-User-Display-Name
      preferredUsernameHeaders: (12)
      - X-Remote-User-Login

1	This provider name is prefixed to the user name in the request header to form an identity name.
2	`RequestHeaderIdentityProvider` can only respond to clients that request `WWW-Authenticate` challenges by redirecting to a configured `challengeURL`. The configured URL should respond with a `WWW-Authenticate` challenge.
3	`RequestHeaderIdentityProvider` can only respond to clients requesting a login flow by redirecting to a configured `loginURL`. The configured URL should respond with a login flow.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	Optional: URL to redirect unauthenticated `/oauth/authorize` requests to, that will authenticate clients which expect `WWW-Authenticate` challenges, and then proxy them to `https://<master>/oauth/authorize`. `${url}` is replaced with the current URL, escaped to be safe in a query parameter. `${query}` is replaced with the current query string.
6	Optional: URL to redirect unauthenticated `/oauth/authorize` requests to, that will authenticate browser-based clients and then proxy their request to `https://<master>/oauth/authorize`. The URL that proxies to `https://<master>/oauth/authorize` must end with `/authorize` (with no trailing slash), and also proxy subpaths, in order for OAuth approval flows to work properly. `${url}` is replaced with the current URL, escaped to be safe in a query parameter. `${query}` is replaced with the current query string.
7	Optional: PEM-encoded certificate bundle. If set, a valid client certificate must be presented and validated against the certificate authorities in the specified file before the request headers are checked for user names.
8	Optional: list of common names (`cn`). If set, a valid client certificate with a Common Name (`cn`) in the specified list must be presented before the request headers are checked for user names. If empty, any Common Name is allowed. Can only be used in combination with `clientCA`.
9	Header names to check, in order, for the user identity. The first header containing a value is used as the identity. Required, case-insensitive.
10	Header names to check, in order, for an email address. The first header containing a value is used as the email address. Optional, case-insensitive.
11	Header names to check, in order, for a display name. The first header containing a value is used as the display name. Optional, case-insensitive.
12	Header names to check, in order, for a preferred user name, if different than the immutable identity determined from the headers specified in `headers`. The first header containing a value is used as the preferred user name when provisioning. Optional, case-insensitive.

SSPI connection support on Microsoft Windows

Using SSPI connection support on Microsoft Windows is a Technology Preview feature. Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information on Red Hat Technology Preview features support scope, see https://access.redhat.com/support/offerings/techpreview/.

Starting in version 3.11,

oc supports the Security Support Provider Interface (SSPI) to allow for SSO flows on Microsft Windows. If you use the request header identity provider with a GSSAPI-enabled proxy to connect an Active Directory server to OpenShift Container Platform, users can automatically authenticate to OpenShift Container Platform by using the oc command line interface from a domain-joined Microsoft Windows computer.

Apache authentication using Request header

This example configures an authentication proxy on the same host as the master. Having the proxy and master on the same host is merely a convenience and may not be suitable for your environment. For example, if you were already running a router on the master, port 443 would not be available.

It is also important to note that while this reference configuration uses Apache’s mod_auth_gssapi, it is by no means required and other proxies can easily be used if the following requirements are met:

Block the X-Remote-User header from client requests to prevent spoofing.
Enforce client certificate authentication in the RequestHeaderIdentityProvider configuration.
Require the X-Csrf-Token header be set for all authentication request using the challenge flow.
Only the /oauth/authorize endpoint and its subpaths should be proxied, and redirects should not be rewritten to allow the backend server to send the client to the correct location.
The URL that proxies to https://<master>/oauth/authorize must end with /authorize (with no trailing slash). For example:
- https://proxy.example.com/login-proxy/authorize?… → https://<master>/oauth/authorize?…
Subpaths of the URL that proxies to https://<master>/oauth/authorize must proxy to subpaths of https://<master>/oauth/authorize. For example:
- https://proxy.example.com/login-proxy/authorize/approve?… → https://<master>/oauth/authorize/approve?…

Installing the prerequisites

Obtain the mod_auth_gssapi module from the Optional channel. Install the following packages:
```
# yum install -y httpd mod_ssl mod_session apr-util-openssl mod_auth_gssapi
```

Generate a CA for validating requests that submit the trusted header. This CA should be used as the file name for clientCA in the master’s identity provider configuration.

# oc adm ca create-signer-cert \
  --cert='/etc/origin/master/proxyca.crt' \
  --key='/etc/origin/master/proxyca.key' \
  --name='openshift-proxy-signer@1432232228' \
  --serial='/etc/origin/master/proxyca.serial.txt'

The oc adm ca create-signer-cert command generates a certificate that is valid for five years. This can be altered with the --expire-days option, but for security reasons, it is recommended to not make it greater than this value.

Run oc adm commands only from the first master listed in the Ansible host inventory file, by default /etc/ansible/hosts.

Generate a client certificate for the proxy. This can be done using any x509 certificate tooling. For convenience, the oc adm CLI can be used:

# oc adm create-api-client-config \
  --certificate-authority='/etc/origin/master/proxyca.crt' \
  --client-dir='/etc/origin/master/proxy' \
  --signer-cert='/etc/origin/master/proxyca.crt' \
  --signer-key='/etc/origin/master/proxyca.key' \
  --signer-serial='/etc/origin/master/proxyca.serial.txt' \
  --user='system:proxy' (1)

# pushd /etc/origin/master
# cp master.server.crt /etc/pki/tls/certs/localhost.crt (2)
# cp master.server.key /etc/pki/tls/private/localhost.key
# cp ca.crt /etc/pki/CA/certs/ca.crt
# cat proxy/system\:proxy.crt \
  proxy/system\:proxy.key > \
  /etc/pki/tls/certs/authproxy.pem
# popd

1 The user name can be anything, however it is useful to give it a descriptive name as it will appear in logs.

2 When running the authentication proxy on a different host name than the master, it is important to generate a certificate that matches the host name instead of using the default master certificate as shown above. The value for masterPublicURL in the /etc/origin/master/master-config.yaml file must be included in the X509v3 Subject Alternative Name in the certificate that is specified for SSLCertificateFile. If a new certificate needs to be created, the oc adm ca create-server-cert command can be used.

The oc adm create-api-client-config command generates a certificate that is valid for two years. This can be altered with the --expire-days option, but for security reasons, it is recommended to not make it greater than this value. Run oc adm commands only from the first master listed in the Ansible host inventory file, by default /etc/ansible/hosts.

Configuring Apache

This proxy does not need to reside on the same host as the master. It uses a client certificate to connect to the master, which is configured to trust the X-Remote-User header.

Create the certificate for the Apache configuration. The certificate that you specify as the SSLProxyMachineCertificateFile parameter value is the proxy’s client cert that is used to authenticate the proxy to the server. It must use TLS Web Client Authentication as the extended key type.

Create the Apache configuration. Use the following template to provide your required settings and values:

Carefully review the template and customize its contents to fit your environment.

LoadModule request_module modules/mod_request.so
LoadModule auth_gssapi_module modules/mod_auth_gssapi.so
# Some Apache configurations might require these modules.
# LoadModule auth_form_module modules/mod_auth_form.so
# LoadModule session_module modules/mod_session.so

# Nothing needs to be served over HTTP.  This virtual host simply redirects to
# HTTPS.
<VirtualHost *:80>
  DocumentRoot /var/www/html
  RewriteEngine              On
  RewriteRule     ^(.*)$     https://%{HTTP_HOST}$1 [R,L]
</VirtualHost>

<VirtualHost *:443>
  # This needs to match the certificates you generated.  See the CN and X509v3
  # Subject Alternative Name in the output of:
  # openssl x509 -text -in /etc/pki/tls/certs/localhost.crt
  ServerName www.example.com

  DocumentRoot /var/www/html
  SSLEngine on
  SSLCertificateFile /etc/pki/tls/certs/localhost.crt
  SSLCertificateKeyFile /etc/pki/tls/private/localhost.key
  SSLCACertificateFile /etc/pki/CA/certs/ca.crt

  SSLProxyEngine on
  SSLProxyCACertificateFile /etc/pki/CA/certs/ca.crt
  # It's critical to enforce client certificates on the Master.  Otherwise
  # requests could spoof the X-Remote-User header by accessing the Master's
  # /oauth/authorize endpoint directly.
  SSLProxyMachineCertificateFile /etc/pki/tls/certs/authproxy.pem

  # Send all requests to the console
  RewriteEngine              On
  RewriteRule     ^/console(.*)$     https://%{HTTP_HOST}:8443/console$1 [R,L]

  # In order to using the challenging-proxy an X-Csrf-Token must be present.
  RewriteCond %{REQUEST_URI} ^/challenging-proxy
  RewriteCond %{HTTP:X-Csrf-Token} ^$ [NC]
  RewriteRule ^.* - [F,L]

  <Location /challenging-proxy/oauth/authorize>
      # Insert your backend server name/ip here.
      ProxyPass https://[MASTER]:8443/oauth/authorize
      AuthName "SSO Login"
      # For Kerberos
      AuthType GSSAPI
      Require valid-user
      RequestHeader set X-Remote-User %{REMOTE_USER}s

      GssapiCredStore keytab:/etc/httpd/protected/auth-proxy.keytab
      # Enable the following if you want to allow users to fallback
      # to password based authntication when they do not have a client
      # configured to perform kerberos authentication
      GssapiBasicAuth On

      # For ldap:
      # AuthBasicProvider ldap
      # AuthLDAPURL "ldap://ldap.example.com:389/ou=People,dc=my-domain,dc=com?uid?sub?(objectClass=*)"

      # It's possible to remove the mod_auth_gssapi usage and replace it with
      # something like mod_auth_mellon, which only supports the login flow.
    </Location>

    <Location /login-proxy/oauth/authorize>
    # Insert your backend server name/ip here.
    ProxyPass https://[MASTER]:8443/oauth/authorize

      AuthName "SSO Login"
      AuthType GSSAPI
      Require valid-user
      RequestHeader set X-Remote-User %{REMOTE_USER}s env=REMOTE_USER

      GssapiCredStore keytab:/etc/httpd/protected/auth-proxy.keytab
      # Enable the following if you want to allow users to fallback
      # to password based authntication when they do not have a client
      # configured to perform kerberos authentication
      GssapiBasicAuth On

      ErrorDocument 401 /login.html
    </Location>

</VirtualHost>

RequestHeader unset X-Remote-User

Configuring the master

The identityProviders stanza in the /etc/origin/master/master-config.yaml file must be updated as well:

  identityProviders:
  - name: requestheader
    challenge: true
    login: true
    provider:
      apiVersion: v1
      kind: RequestHeaderIdentityProvider
      challengeURL: "https://[MASTER]/challenging-proxy/oauth/authorize?${query}"
      loginURL: "https://[MASTER]/login-proxy/oauth/authorize?${query}"
      clientCA: /etc/origin/master/proxyca.crt
      headers:
      - X-Remote-User

Restarting services

Finally, restart the following services:

# systemctl restart httpd
# master-restart api
# master-restart controllers

Verifying the configuration

Test by bypassing the proxy. You should be able to request a token if you supply the correct client certificate and header:

# curl -L -k -H "X-Remote-User: joe" \
   --cert /etc/pki/tls/certs/authproxy.pem \
   https://[MASTER]:8443/oauth/token/request

If you do not supply the client certificate, the request should be denied:

# curl -L -k -H "X-Remote-User: joe" \
   https://[MASTER]:8443/oauth/token/request

This should show a redirect to the configured challengeURL (with additional query parameters):

# curl -k -v -H 'X-Csrf-Token: 1' \
   '<masterPublicURL>/oauth/authorize?client_id=openshift-challenging-client&response_type=token'

This should show a 401 response with a WWW-Authenticate basic challenge, a negotiate challenge, or both challenges:
```
#  curl -k -v -H 'X-Csrf-Token: 1' \
    '<redirected challengeURL from step 3 +query>'
```
Test logging into the oc command line with and without using a Kerberos ticket:
1. If you generated a Kerberos ticket by using kinit, destroy it:
  # kdestroy -c cache_name (1)
  1 Provide the name of your Kerberos cache.
2. Log in to the oc command line by using your Kerberos credentials:
  # oc login
  Enter your Kerberos user name and password at the prompt.
3. Log out of the oc command line:
  # oc logout
4. Use your Kerberos credentials to get a ticket:
  # kinit
  Enter your Kerberos user name and password at the prompt.
5. Confirm that you can log in to the oc command line:
  # oc login
  If your configuration is correct, you are logged in without entering separate credentials.

GitHub and GitHub Enterprise

GitHub uses OAuth, and you can integrate your OpenShift Container Platform cluster to use that OAuth authentication. OAuth facilitates a token exchange flow between OpenShift Container Platform and GitHub or GitHub Enterprise.

You can use the GitHub integration to connect to either GitHub or GitHub Enterprise. For GitHub Enterprise integrations, you must provide the hostname of your instance and can optionally provide a ca certificate bundle to use in requests to the server.

The following steps apply to both GitHub and GitHub Enterprise unless noted.

Configuring GitHub authentication allows users to log in to OpenShift Container Platform with their GitHub credentials. To prevent anyone with any GitHub user ID from logging in to your OpenShift Container Platform cluster, you can restrict access to only those in specific GitHub organizations.

Registering the application on GitHub

Register an application:
- For GitHub, click Settings → Developer settings → Register a new OAuth application.
- For GitHub Enterprise, go to your GitHub Enterprise home page and then click Settings → Developer settings → Register a new application.
Enter an application name, for example My OpenShift Install.
Enter a homepage URL, such as https://myapiserver.com:8443.
Optionally, enter an application description.
Enter the authorization callback URL, where the end of the URL contains the identity provider name, which is defined in the identityProviders stanza of the master configuration file, which you configure in the next section of this topic:
```
<apiserver>/oauth2callback/<identityProviderName>
```
For example:
```
https://myapiserver.com:8443/oauth2callback/github/
```
Click Register application. GitHub provides a Client ID and a Client Secret. Keep this window open so you can copy these values and paste them into the master configuration file.

Configuring authentication on the master

If you have:

Already installed OpenShift Container Platform, then copy the /etc/origin/master/master-config.yaml file into a new directory, for example:
```
$ cd /etc/origin/master
$ mkdir githubconfig; cp master-config.yaml githubconfig
```

$ openshift start master --public-master=<apiserver> --write-config=<directory>

For example:

$ openshift start master --public-master=https://myapiserver.com:8443 --write-config=githubconfig

Using openshift start master on its own would auto-detect host names, but GitHub must be able to redirect to the exact host name that you specified when registering the application. For this reason, you cannot auto-detect the ID because it might redirect to the wrong address. Instead, you must specify the hostname that web browsers use to interact with your OpenShift Container Platform cluster.

Edit the new master-config.yaml file’s identityProviders stanza, and copy the example GitHubIdentityProvider configuration and paste it to replace the existing stanza:

oauthConfig:
  ...
  identityProviders:
  - name: github (1)
    challenge: false (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: GitHubIdentityProvider
      ca: ... (5)
      clientID: ... (6)
      clientSecret: ... (7)
      hostname: ... (8)
      organizations: (9)
      - myorganization1
      - myorganization2
      teams: (10)
      - myorganization1/team-a
      - myorganization2/team-b

1	This provider name is prefixed to the GitHub numeric user ID to form an identity name. It is also used to build the callback URL.
2	`GitHubIdentityProvider` cannot be used to send `WWW-Authenticate` challenges.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to GitHub to log in.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	For GitHub Enterprise, the CA is the optional trusted certificate authority bundle to use when making requests to the server. Omit this parameter to use the default system root certificates. For GitHub, omit this parameter.
6	The client ID of a registered GitHub OAuth application. The application must be configured with a callback URL of `<master>/oauth2callback/<identityProviderName>`.
7	The client secret issued by GitHub. This value may also be provided in an environment variable, external file, or encrypted file.
8	For GitHub Enterprise, you must provide the host name of your instance, such as `example.com`. This value must match the GitHub Enterprise `hostname` value in in the */setup/settings* file and cannot include a port number. For GitHub, omit this parameter.
9	Optional list of organizations. If specified, only GitHub users that are members of at least one of the listed organizations will be allowed to log in. If the GitHub OAuth application configured in `clientID` is not owned by the organization, an organization owner must grant third-party access in order to use this option. This can be done during the first GitHub login by the organization’s administrator, or from the GitHub organization settings. Cannot be used in combination with the `teams` field.
10	Optional list of teams. If specified, only GitHub users that are members of at least one of the listed teams will be allowed to log in. If the GitHub OAuth application configured in `clientID` is not owned by the team’s organization, an organization owner must grant third-party access in order to use this option. This can be done during the first GitHub login by the organization’s administrator, or from the GitHub organization settings. Cannot be used in combination with the `organizations` field.

Make the following modifications to the identityProviders stanza:
1. Change the provider name to match the callback URL you configured on GitHub.
  
  For example, if you defined the callback URL as https://myapiserver.com:8443/oauth2callback/github/ then the name must be github.
2. Change clientID to the Client ID from GitHub that you registered previously.
3. Change clientSecret to the Client Secret from GitHub that you registered previously.
4. Change organizations or teams to include a list of one or more GitHub organizations or teams to which a user must have membership in order to authenticate. If specified, only GitHub users that are members of at least one of the listed organizations or teams will be allowed to log in. If this is not specified, then any person with a valid GitHub account can log in.
Save your changes and close the file.
Start the OpenShift Container Platform API server, specifying the configuration file you just modified:
```
$ openshift start master --config=<path/to/modified/config>/master-config.yaml
```

Once configured, any user logging in to the OpenShift Container Platform web console will be prompted to log in using their GitHub credentials. On their first login, the user must click authorize application to permit GitHub to use their user name, password, and organization membership with OpenShift Container Platform. The user is then redirected back to the web console.

Creating users with GitHub authentication

You do not create users in OpenShift Container Platform when integrating with an external authentication provider, such as, in this case, GitHub. GitHub, or GitHub Enterprise, is the system of record, meaning that users are defined by GitHub, and any user belonging to a specified organization can log in.

To add a user to OpenShift Container Platform, you must add that user to an approved organization on GitHub or GitHub Enterprise, and if required create a new GitHub account for the user.

Verifying users

Once one or more users have logged in, you can run oc get users to view a list of users and verify that users were created successfully:

Example 6. Output of oc get users command

$ oc get users
NAME         UID                                    FULL NAME   IDENTITIES
bobsmith     433b5641-066f-11e6-a6d8-acfc32c1ca87   Bob Smith   github:873654 (1)

Identities in OpenShift Container Platform are comprised of the identity provider name and GitHub’s internal numeric user ID. This way, if a user changes their GitHub user name or e-mail they can still log in to OpenShift Container Platform instead of relying on the credentials attached to the GitHub account. This creates a stable login.

From here, you might want to learn how to control user roles.

GitLab

Set GitLabIdentityProvider in the identityProviders stanza to use GitLab.com or any other GitLab instance as an identity provider. If you use GitLab version 7.7.0 to 11.0, you connect using the OAuth integration. If you use GitLab version 11.1 or later, you can use OpenID Connect (OIDC) to connect instead of OAuth.

Example 7. Master configuration using GitLabIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: gitlab (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: GitLabIdentityProvider
      legacy: (5)
      url: ... (6)
      clientID: ... (7)
      clientSecret: ... (8)
      ca: ... (9)

1	This provider name is prefixed to the GitLab numeric user ID to form an identity name. It is also used to build the callback URL.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider. This uses the Resource Owner Password Credentials grant flow to obtain an access token from GitLab.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to GitLab to log in.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	Determines whether to use OAuth or OIDC as the authentication provider. Set to `true` to use OAuth and `false` to use OIDC. You must use GitLab.com or GitLab version 11.1 or later to use OIDC. If you do not provide a value, OAuth is used to connect to your GitLab instance, and OIDC is used to connect to GitLab.com.
6	The host URL of a GitLab provider. This could either be `https://gitlab.com/` or any other self hosted instance of GitLab.
7	The client ID of a registered GitLab OAuth application. The application must be configured with a callback URL of `<master>/oauth2callback/<identityProviderName>`.
8	The client secret issued by GitLab. This value may also be provided in an environment variable, external file, or encrypted file.
9	CA is an optional trusted certificate authority bundle to use when making requests to the GitLab instance. If empty, the default system roots are used.

Google

Set GoogleIdentityProvider in the identityProviders stanza to use Google as an identity provider, using Google’s OpenID Connect integration.

Using Google as an identity provider requires users to get a token using <master>/oauth/token/request to use with command-line tools.

Using Google as an identity provider allows any Google user to authenticate to your server. You can limit authentication to members of a specific hosted domain with the hostedDomain configuration attribute, as shown below.

Example 8. Master configuration using GoogleIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: google (1)
    challenge: false (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: GoogleIdentityProvider
      clientID: ... (5)
      clientSecret: ... (6)
      hostedDomain: "" (7)

1	This provider name is prefixed to the Google numeric user ID to form an identity name. It is also used to build the redirect URL.
2	`GoogleIdentityProvider` cannot be used to send `WWW-Authenticate` challenges.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to Google to log in.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	The client ID of a registered Google project. The project must be configured with a redirect URI of `<master>/oauth2callback/<identityProviderName>`.
6	The client secret issued by Google. This value may also be provided in an environment variable, external file, or encrypted file.
7	Optional hosted domain to restrict sign-in accounts to. If empty, any Google account is allowed to authenticate.

OpenID connect

Set OpenIDIdentityProvider in the identityProviders stanza to integrate with an OpenID Connect identity provider using an Authorization Code Flow.

You can configure Red Hat Single Sign-On as an OpenID Connect identity provider for OpenShift Container Platform.

ID Token and UserInfo decryptions are not supported.

By default, the openid scope is requested. If required, extra scopes can be specified in the extraScopes field.

Claims are read from the JWT id_token returned from the OpenID identity provider and, if specified, from the JSON returned by the UserInfo URL.

At least one claim must be configured to use as the user’s identity. The standard identity claim is sub.

You can also indicate which claims to use as the user’s preferred user name, display name, and email address. If multiple claims are specified, the first one with a non-empty value is used. The standard claims are:

`sub`	Short for "subject identifier." The remote identity for the user at the issuer.
`preferred_username`	The preferred user name when provisioning a user. A shorthand name that the user wants to be referred to as, such as `janedoe`. Typically a value that corresponding to the user’s login or username in the authentication system, such as username or email.
`email`	Email address.
`name`	Display name.

See the OpenID claims documentation for more information.

Using an OpenID Connect identity provider requires users to get a token using <master>/oauth/token/request to use with command-line tools.

Standard Master configuration using OpenIDIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_openid_connect (1)
    challenge: true (2)
    login: true (3)
    mappingMethod: claim (4)
    provider:
      apiVersion: v1
      kind: OpenIDIdentityProvider
      clientID: ... (5)
      clientSecret: ... (6)
      claims:
        id: (7)
        - sub
        preferredUsername:
        - preferred_username
        name:
        - name
        email:
        - email
      urls:
        authorize: https://myidp.example.com/oauth2/authorize (8)
        token: https://myidp.example.com/oauth2/token (9)

1	This provider name is prefixed to the value of the identity claim to form an identity name. It is also used to build the redirect URL.
2	When `true`, unauthenticated token requests from non-web clients (like the CLI) are sent a `WWW-Authenticate` challenge header for this provider. This requires the OpenID provider to support the Resource Owner Password Credentials grant flow.
3	When `true`, unauthenticated token requests from web clients (like the web console) are redirected to the authorize URL to log in.
4	Controls how mappings are established between this provider’s identities and user objects, as described above.
5	The client ID of a client registered with the OpenID provider. The client must be allowed to redirect to `<master>/oauth2callback/<identityProviderName>`.
6	The client secret. This value may also be provided in an environment variable, external file, or encrypted file.
7	List of claims to use as the identity. First non-empty claim is used. At least one claim is required. If none of the listed claims have a value, authentication fails. For example, this uses the value of the `sub` claim in the returned `id_token` as the user’s identity.
8	Authorization Endpoint described in the OpenID spec. Must use `https`.
9	Token Endpoint described in the OpenID spec. Must use `https`.

A custom certificate bundle, extra scopes, extra authorization request parameters, and userInfo URL can also be specified:

Example 9. Full Master configuration using OpenIDIdentityProvider

oauthConfig:
  ...
  identityProviders:
  - name: my_openid_connect
    challenge: false
    login: true
    mappingMethod: claim
    provider:
      apiVersion: v1
      kind: OpenIDIdentityProvider
      clientID: ...
      clientSecret: ...
      ca: my-openid-ca-bundle.crt (1)
      extraScopes: (2)
      - email
      - profile
      extraAuthorizeParameters: (3)
        include_granted_scopes: "true"
      claims:
        id: (4)
        - custom_id_claim
        - sub
        preferredUsername: (5)
        - preferred_username
        - email
        name: (6)
        - nickname
        - given_name
        - name
        email: (7)
        - custom_email_claim
        - email
      urls:
        authorize: https://myidp.example.com/oauth2/authorize
        token: https://myidp.example.com/oauth2/token
        userInfo: https://myidp.example.com/oauth2/userinfo (8)

1	Certificate bundle to use to validate server certificates for the configured URLs. If empty, system trusted roots are used.
2	Optional list of scopes to request, in addition to the openid scope, during the authorization token request.
3	Optional map of extra parameters to add to the authorization token request.
4	List of claims to use as the identity. First non-empty claim is used. At least one claim is required. If none of the listed claims have a value, authentication fails.
5	List of claims to use as the preferred user name when provisioning a user for this identity. First non-empty claim is used.
6	List of claims to use as the display name. First non-empty claim is used.
7	List of claims to use as the email address. First non-empty claim is used.
8	UserInfo Endpoint described in the OpenID spec. Must use `https`.

Token options

The OAuth server generates two kinds of tokens:

Access tokens	Longer-lived tokens that grant access to the API.
Authorize codes	Short-lived tokens whose only use is to be exchanged for an access token.

Use the tokenConfig stanza to set token options:

Example 10. Master Configuration Token Options

oauthConfig:
  ...
  tokenConfig:
    accessTokenMaxAgeSeconds: 86400 (1)
    authorizeTokenMaxAgeSeconds: 300 (2)

1	Set `accessTokenMaxAgeSeconds` to control the lifetime of access tokens. The default lifetime is 24 hours.
2	Set `authorizeTokenMaxAgeSeconds` to control the lifetime of authorize codes. The default lifetime is five minutes.

You can override the accessTokenMaxAgeSeconds value through an OAuthClient object definition.

Grant options

When the OAuth server receives token requests for a client to which the user has not previously granted permission, the action that the OAuth server takes is dependent on the OAuth client’s grant strategy.

When the OAuth client requesting token does not provide its own grant strategy, the server-wide default strategy is used. To configure the default strategy, set the method value in the grantConfig stanza. Valid values for method are:

`auto`	Auto-approve the grant and retry the request.
`prompt`	Prompt the user to approve or deny the grant.
`deny`	Auto-deny the grant and return a failure error to the client.

Example 11. Master Configuration Grant Options

oauthConfig:
  ...
  grantConfig:
    method: auto

Session options

The OAuth server uses a signed and encrypted cookie-based session during login and redirect flows.

Use the sessionConfig stanza to set session options:

Example 12. Master Configuration Session Options

oauthConfig:
  ...
  sessionConfig:
    sessionMaxAgeSeconds: 300 (1)
    sessionName: ssn (2)
    sessionSecretsFile: "..." (3)

1	Controls the maximum age of a session; sessions auto-expire once a token request is complete. If auto-grant is not enabled, sessions must last as long as the user is expected to take to approve or reject a client authorization request.
2	Name of the cookie used to store the session.
3	File name containing serialized `SessionSecrets` object. If empty, a random signing and encryption secret is generated at each server start.

If no sessionSecretsFile is specified, a random signing and encryption secret is generated at each start of the master server. This means that any logins in progress will have their sessions invalidated if the master is restarted. It also means they will not be able to decode sessions generated by one of the other masters.

To specify the signing and encryption secret to use, specify a sessionSecretsFile. This allows you separate secret values from the configuration file and keep the configuration file distributable, for example for debugging purposes.

Multiple secrets can be specified in the sessionSecretsFile to enable rotation. New sessions are signed and encrypted using the first secret in the list. Existing sessions are decrypted and authenticated by each secret until one succeeds.

Example 13. Session Secret Configuration:

apiVersion: v1
kind: SessionSecrets
secrets: (1)
- authentication: "..." (2)
  encryption: "..." (3)
- authentication: "..."
  encryption: "..."
...

1	List of secrets used to authenticate and encrypt cookie sessions. At least one secret must be specified. Each secret must set an authentication and encryption secret.
2	Signing secret, used to authenticate sessions using HMAC. Recommended to use a secret with 32 or 64 bytes.
3	Encrypting secret, used to encrypt sessions. Must be 16, 24, or 32 characters long, to select AES-128, AES-192, or AES-256.

Preventing CLI version mismatch with user agent

OpenShift Container Platform implements a user agent that can be used to prevent an application developer’s CLI from accessing the OpenShift Container Platform API.

User agents for the OpenShift Container Platform CLI are constructed from a set of values within OpenShift Container Platform:

<command>/<version>+<git_commit> (<platform>/<architecture>) <client>/<git_commit>

So, for example, when:

<command> = oc
<version> = The client version. For example, v3.3.0. Requests made against the Kubernetes API at /api receive the Kubernetes version, while requests made against the OpenShift Container Platform API at /oapi receive the OpenShift Container Platform version (as specified by oc version)
<platform> = linux
<architecture> = amd64
<client> = openshift, or kubernetes depending on if the request is made against the Kubernetes API at /api, or the OpenShift Container Platform API at /oapi
<git_commit> = The Git commit of the client version (for example, f034127)

the user agent will be:

oc/v3.3.0+f034127 (linux/amd64) openshift/f034127

You must configure the user agent in the master configuration file, /etc/origin/master/master-config.yaml. To apply the configuration, restart the API server:

$ /usr/local/bin/master-restart api

As an OpenShift Container Platform administrator, you can prevent clients from accessing the API with the userAgentMatching configuration setting of a master configuration. So, if a client is using a particular library or binary, they will be prevented from accessing the API.

The following user agent example denies the Kubernetes 1.2 client binary, OpenShift Origin 1.1.3 binary, and the POST and PUT httpVerbs:

policyConfig:
  userAgentMatchingConfig:
    defaultRejectionMessage: "Your client is too old.  Go to https://example.org to update it."
    deniedClients:
    - regex: '\w+/v(?:(?:1\.1\.1)|(?:1\.0\.1)) \(.+/.+\) openshift/\w{7}'
    - regex: '\w+/v(?:1\.1\.3) \(.+/.+\) openshift/\w{7}'
      httpVerbs:
      - POST
      - PUT
    - regex: '\w+/v1\.2\.0 \(.+/.+\) kubernetes/\w{7}'
      httpVerbs:
      - POST
      - PUT
    requiredClients: null

Administrators can also deny clients that do not exactly match the expected clients:

policyConfig:
  userAgentMatchingConfig:
    defaultRejectionMessage: "Your client is too old.  Go to https://example.org to update it."
    deniedClients: []
    requiredClients:
    - regex: '\w+/v1\.1\.3 \(.+/.+\) openshift/\w{7}'
    - regex: '\w+/v1\.2\.0 \(.+/.+\) kubernetes/\w{7}'
      httpVerbs:
      - POST
      - PUT

To deny a client that would otherwise be included in a set of allowed clients, use deniedClients and requiredClients values together. The following example allows all 1.X client binaries except for 1.13:

policyConfig:
  userAgentMatchingConfig:
    defaultRejectionMessage: "Your client is too old.  Go to https://example.org to update it."
    deniedClients:
    - regex: '\w+/v1\.13.0\+\w{7} \(.+/.+\) openshift/\w{7}'
    - regex: '\w+/v1\.13.0\+\w{7} \(.+/.+\) kubernetes/\w{7}'
    requiredClients:
    - regex: '\w+/v1\.[1-9][1-9].[0-9]\+\w{7} \(.+/.+\) openshift/\w{7}'
    - regex: '\w+/v1\.[1-9][1-9].[0-9]\+\w{7} \(.+/.+\) kubernetes/\w{7}'

When the client’s user agent mismatches the configuration, errors occur. To ensure that mutating requests match, enforce a whitelist. Rules are mapped to specific verbs, so you can ban mutating requests while allowing non-mutating requests.

Overview

Identity provider parameters

Configuring identity providers

Configuring identity providers with Ansible

Configuring identity providers in the master configuration file

Manually provisioning a user when using the lookup mapping method

Allow all

Deny all

HTPasswd

Keystone

Configuring authentication on the master

Creating Users with Keystone Authentication

Verifying Users

LDAP authentication

Basic authentication (remote)

Configuring authentication on the master

Troubleshooting

Request header

SSPI connection support on Microsoft Windows

Apache authentication using Request header

Installing the prerequisites

Configuring Apache

Configuring the master

Restarting services

Verifying the configuration

GitHub and GitHub Enterprise

Registering the application on GitHub

Configuring authentication on the master

Creating users with GitHub authentication

Verifying users

GitLab

Google

OpenID connect

Token options

Grant options

Session options

Preventing CLI version mismatch with user agent