Overview

Developers can define settings in specific build configurations within their projects, such as configuring a proxy for Git cloning. Rather than requiring developers to define certain settings in each of their build configurations, cluster administrators can use admission control plug-ins to configure global build defaults and overrides that automatically use these settings in any build.

The settings from these plug-ins are not set in the build configurations or builds themselves, but rather are only used during the build process. This allows administrators to change the global configuration at any time, and any builds that are re-run from existing build configurations or builds will get the new settings.

The BuildDefaults admission control plug-in allows administrators to set global defaults for settings such as the Git HTTP and HTTPS proxy, as well as default environment variables. These defaults do not overwrite values that have been configured for a specific build. However, if those values are not present on the build definition, they are set to the default value.

The BuildOverrides admission control plug-in allows administrators to override a setting in a build, regardless of the value stored in the build. It currently supports overriding the forcePull flag on a build strategy to enforce always refreshing the local image during a build by pulling the image from the registry. This ensures that a user can only build with an image that they are allowed to pull.

Setting Global Build Defaults

You can set global build defaults two ways:

Configuring Global Build Defaults with Ansible

During advanced installations, the BuildDefaults plug-in can be configured using the following parameters, which are configurable in the inventory file:

  • openshift_builddefaults_http_proxy

  • openshift_builddefaults_https_proxy

  • openshift_builddefaults_no_proxy

  • openshift_builddefaults_git_http_proxy

  • openshift_builddefaults_git_https_proxy

Example 1. Example Build Defaults Configuration with Ansible
# These options configure the BuildDefaults admission controller which injects
# environment variables into Builds. These values will default to the global proxy
# config values. You only need to set these if they differ from the global settings
# above. See BuildDefaults
# documentation at https://docs.openshift.org/latest/admin_guide/build_defaults_overrides.html
#openshift_builddefaults_http_proxy=http://USER:PASSWORD@HOST:PORT
openshift_builddefaults_https_proxy=https://USER:PASSWORD@HOST:PORT
openshift_builddefaults_no_proxy=build_defaults
openshift_builddefaults_git_http_proxy=http://USER:PASSWORD@HOST:PORT
openshift_builddefaults_git_https_proxy=https://USER:PASSWORD@HOST:PORT
# Or you may optionally define your own serialized as json
#openshift_builddefaults_json='{"BuildDefaults":{"configuration":{"apiVersion":"v1","env":[{"name":"HTTP_PROXY","value":"http://proxy.example.com.redhat.com:3128"},{"name":"NO_PROXY","value":"ose3-master.example.com"}],"gitHTTPProxy":"http://proxy.example.com:3128","kind":"BuildDefaultsConfig"}}}'

There are additional proxy settings that can be configured for builds using Ansible parameters. For example: - The openshift_builddefaults_git_http_proxy and openshift_builddefaults_git_https_proxy parameters allow you to use a proxy for git cloning - The openshift_builddefaults_http_proxy and openshift_builddefaults_https_proxy parameters can make environment variables available to the Docker build strategy and Custom build strategy processes.

Manually Setting Global Build Defaults

To configure the BuildDefaults plug-in, add a configuration for it in the /etc/origin/master/master-config.yaml file on masters:

kubernetesMasterConfig:
  admissionConfig:
    pluginConfig:
      BuildDefaults:
        configuration:
          apiVersion: v1
          kind: BuildDefaultsConfig
          gitHTTPProxy: http://my.proxy:8080 (1)
          gitHTTPSProxy: https://my.proxy:8443 (2)
          env:
          - name: HTTP_PROXY (3)
            value: http://my.proxy:8080
          - name: HTTPS_PROXY (4)
            value: https://my.proxy:8443
          - name: CUSTOM_VAR (5)
            value: custom_value
1 Sets the HTTP proxy to use when cloning source code from a Git repository.
2 Sets the HTTPS proxy to use when cloning source code from a Git repository.
3 Default environment variable that sets the HTTP proxy to use during the build. This may be used for downloading dependencies during the assemble and build phases.
4 Default environment variable that sets the HTTPS proxy to use during the build. This may be used for downloading dependencies during the assemble and build phases.
5 (Optional) Additional default environment variable that will be added to every build.

Restart the master service for the changes to take effect:

# systemctl restart atomic-openshift-master

Setting Global Build Overrides

To configure the BuildOverrides plug-in, add a configuration for it in the /etc/origin/master/master-config.yaml file on masters:

kubernetesMasterConfig:
  admissionConfig:
    pluginConfig:
      BuildOverrides:
        configuration:
          apiVersion: v1
          kind: BuildOverridesConfig
          forcePull: true  (1)
1 Force all builds to pull their builder image and any source images before starting the build.

Restart the master service for the changes to take effect:

# systemctl restart atomic-openshift-master