Accessing secrets and config maps from functions using the CLI - Configuring functions | Functions

Modifying function access to secrets and config maps interactively
Modifying function access to secrets and config maps interactively by using specialized commands

After your functions have been deployed to the cluster, they can access data stored in secrets and config maps. This data can be mounted as volumes, or assigned to environment variables. You can configure this access interactively by using the Knative CLI, or by manually by editing the function configuration YAML file.

To access secrets and config maps, the function must be deployed on the cluster. This functionality is not available to a function running locally.

If a secret or config map value cannot be accessed, the deployment fails with an error message specifying the inaccessible values.

Modifying function access to secrets and config maps interactively

You can manage the secrets and config maps accessed by your function by using the kn func config interactive utility. The available operations include listing, adding, and removing values stored in config maps and secrets as environment variables, as well as listing, adding, and removing volumes. This functionality enables you to manage what data stored on the cluster is accessible by your function.

Prerequisites

The OpenShift Serverless Operator and Knative Serving are installed on the cluster.
You have installed the Knative (kn) CLI.
You have created a function.

Procedure

Run the following command in the function project directory:
```
$ kn func config
```
Alternatively, you can specify the function project directory using the --path or -p option.

Use the interactive interface to perform the necessary operation. For example, using the utility to list configured volumes produces an output similar to this:

$ kn func config
? What do you want to configure? Volumes
? What operation do you want to perform? List
Configured Volumes mounts:
- Secret "mysecret" mounted at path: "/workspace/secret"
- Secret "mysecret2" mounted at path: "/workspace/secret2"

This scheme shows all operations available in the interactive utility and how to navigate to them:

kn func config
   ├─> Environment variables
   │               ├─> Add
   │               │    ├─> ConfigMap: Add all key-value pairs from a config map
   │               │    ├─> ConfigMap: Add value from a key in a config map
   │               │    ├─> Secret: Add all key-value pairs from a secret
   │               │    └─> Secret: Add value from a key in a secret
   │               ├─> List: List all configured environment variables
   │               └─> Remove: Remove a configured environment variable
   └─> Volumes
           ├─> Add
           │    ├─> ConfigMap: Mount a config map as a volume
           │    └─> Secret: Mount a secret as a volume
           ├─> List: List all configured volumes
           └─> Remove: Remove a configured volume

Optional. Deploy the function to make the changes take effect:
```
$ kn func deploy -p test
```

Modifying function access to secrets and config maps interactively by using specialized commands

Every time you run the kn func config utility, you need to navigate the entire dialogue to select the operation you need, as shown in the previous section. To save steps, you can directly execute a specific operation by running a more specific form of the kn func config command:

To list configured environment variables:

$ kn func config envs [-p <function-project-path>]

To add environment variables to the function configuration:
```
$ kn func config envs add [-p <function-project-path>]
```
To remove environment variables from the function configuration:
```
$ kn func config envs remove [-p <function-project-path>]
```

To list configured volumes:

$ kn func config volumes [-p <function-project-path>]

To add a volume to the function configuration:

$ kn func config volumes add [-p <function-project-path>]

To remove a volume from the function configuration:

$ kn func config volumes remove [-p <function-project-path>]

Accessing secrets and config maps from functions using CLI

Modifying function access to secrets and config maps interactively

Modifying function access to secrets and config maps interactively by using specialized commands