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Configuring micro-gw.conf for Kubernetes¶

You can use environment variables when running Kubernetes to override the configurations in the <MGW-RUNTIME-HOME>/conf/micro-gw.conf file.

You need to create the variable name by appending the micro-gw.conf configuration hierarchy by using an _ underscore to define each level of the hierarchy.

Example 1 - Defining the Listener HTTPS port with secret references¶

Note

It is mandatory to define secret references when working with sensitive data such as user credentials.

Let’s assume that you are going to override the assigned value for httpPort, which is under [listenerConfig].

[listenerConfig]
 ...
  httpPort = 9090
  ...

Create a Kubernetes secret for the configuration.
1. Create a file (secret.yaml) with the following content.
  
  The data attributes need to be base64 encoded. Therefore, in this case the encoded value for 8000 has been added in the following code snippet.
```
apiVersion: v1
kind: Secret
metadata:
  name: test-secret
data:
  port: ODAwMA==
```
2. Create the secret.
  Format
```
kubectl apply -f <file-path>/<secret-file-name.yaml>
```
  Example
```
kubectl apply -f file-path/secret.yaml
```

Declare the secret as an environment variable in the deployment-config.toml file.

Format

  [kubernetes]
      [kubernetes.kubernetesDeployment]
          enable = true
          ...
          env = '{ "<environment-variable>": {secretKeyRef: {key: "<configuration>",name: "<secret-name>"}} }'

Example

  [kubernetes]
      [kubernetes.kubernetesDeployment]
          enable = true
          ...
          env = '{ "listenerConfig_httpPort": {secretKeyRef: {key: "port",name: "test-secret"}} }'

As the httpPort configuration is under the listenerConfig, the variable name can be obtained by appending both with an underscore_.
You need to use the same key (e.g., port) and the name (e.g., test-secret) of the secret that you created.

Generate the Kubernetes artifacts by building the project.

micro-gw build k8s_project — deployment-config deployment.toml

The following is the generated Kubernetes artifact (k8s_project.yaml) content with the environment variable.

  ...
  spec:
        containers:
        - env:
          - name: "listenerConfig_httpPort"
            valueFrom:
              secretKeyRef:
                key: "port"
                name: "test-secret"
          - name: "CONFIG_FILE"
            value: "/home/ballerina/conf/ballerina.conf"
  ...

Start the Kubernetes cluster.

Example 2 - Defining the Listener HTTPS port without secret references¶

Let’s assume that you want to fetch the configuration of httpPort, which is under [listenerConfig].

[listenerConfig]
 ...
  httpPort = 9090
  ...

Declare the secret as an environment variable in the deployment-config.toml file.

Format

  [kubernetes]
      [kubernetes.kubernetesDeployment]
          enable = true
          ...
          env = '{ "<environment-variable-name>": "<environment-variable-value>" }'

Example

  [kubernetes]
      [kubernetes.kubernetesDeployment]
          enable = true
          ...
          env = '{ "listenerConfig_httpPort": 9090 }'

Tip

You can define multiple environment variables in the deployment-config.toml file as follows:

env = '{ "<environment-variable-name1>": "<environment-variable-value1>", "<environment-variable-name2>": "<environment-variable-value2>" }'

As the httpPort configuration is under the listenerConfig, the variable name can be obtained by appending both with an underscore_.

Generate the Kubernetes artifacts by building the project.

micro-gw build k8s_project — deployment-config deployment.toml

The following is the generated Kubernetes artifact (k8s_project.yaml) content with the environment variable.

  ...
  spec:
        containers:
        - env:
          - name: "listenerConfig_httpPort"
            value: 9091
          - name: "CONFIG_FILE"
            value: "/home/ballerina/conf/ballerina.conf"
  ...

Start the Kubernetes cluster.

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