Applying Custom Policies

Applying custom policies is the same as applying included policies.

When applying custom policies, the configuration parameters are defined in definition/gcl.yaml.

To learn more about defining configuration parameters, see Defining a Policy Schema Definition.

Before You Begin

Compile your custom policy.
If applying your custom policy to Flex Gateway running in Connected Mode, upload your custom policy to Exchange.

Apply Policies in Connected Mode

When you apply a custom policy in Connected Mode, the configuration parameters and metadata defined in gcl.yaml appear in the API Manager UI.

To apply a custom policy in Connected Mode, see Apply a Policy in Connected Mode.

Update Policies in Connected Mode

To update a custom policy in API Manager:

Go to Anypoint Platform > API Manager.
In API Administration click the name of the API to which to apply a policy.
From the left navigation menu, click Policies.
Click the more options button () of the policy you want to update, and then click Edit configuration.
Select the latest version for Policy version configuration parameter.
Click Save.
Click the more options button () of the policy you want to update, and then click Check for implementation updates.

For more information about implementation updates, see Update Policy Implementations.
In the confirmation dialog box, click Update all.

Apply Policies in Local Mode

For Flex Gateway running in Local Mode, you apply custom policies using local declarative configuration files. You specify the location of these configuration files when you first run Flex Gateway.

To create the local declarative files:

In the target/wasm32-wasi/release PDK directory, copy both of the following files:
- <your_custom_policy>_definition.yaml
- <your_custom_policy>_implementation.yaml
Paste the two files in the /etc/mulesoft/flex-gateway/conf.d/ Flex Gateway configuration directory.
Create a policy binding configuration file with a .yaml file extension to bind the policy to an API instance:
- Give the file a custom name.
- Save the file in the Flex Gateway configuration directory /etc/mulesoft/flex-gateway/conf.d/custom. This directory can contain multiple configuration files.
Copy and paste the following YAML snippet into the file, substituting your values where indicated:
```
apiVersion: gateway.mulesoft.com/v1alpha1
kind: PolicyBinding
metadata:
  name: <custom-policy-id>
spec:
  targetRef:
    kind: ApiInstance
    name: <your-api-instance>
  policyRef:
    kind: Extension
    name: <your_custom_policy>-<version>-impl
  config:
    <custom-cofiguration-parameters>: "your parameter"
```
- metadata.name: The custom policy instance name.
- spec.targetRef.name: The name of the API instance of which to apply the custom policy. The API instance must already have been defined and applied.
- spec.policyRef.name: The custom policy implementation ID. To get the policy ID, run the make show-policy-ref-name command from the policy’s root directory.
- spec.config: Your policy configuration data.
Save the file. The gateway automatically refreshes the configuration.

Update Policies in Local Mode

To update a custom policy for Flex Gateway running in Local Mode:

If you did not edit the configuration parameters, replace your old <your_custom_policy>_implementation.yaml in your Flex Gateway configuration directory with the implementation file from your target/wasm32-wasi/release PDK directory.
If you did edit the configuration parameters, repeat the steps in Apply Policies in Local Mode to update your configuration parameters.

Reorder Custom Policies

Reordering custom policies is the same as reordering included policies.

To reorder policies, see Ordering Policies.

Polices execute in order on the request and then in inverse order on the response. However, some policies do not execute on both the request and the response.

For example, policies ordered:

Policy X
Policy Y

Execute Policy X then Policy Y on the request, and Policy Y then Policy X on the response.