Manage runtime plane components

This topic explains how to configure and manage the Apigee hybrid runtime plane components. For a list of the runtime plane components that you can configure, see Runtime service configuration overview.

About the overrides file

The first time you install the hybrid runtime into a cluster, you must create a configuration overrides file. This file lets you override default configuration values as needed, configure environments, reference TLS certificates and service account keys, assign Kubernetes node pools to specific hybrid components, and so on.

The hybrid installation steps walk through the process of creating an overrides file and applying your configuration to a cluster. If you want to change the configuration later, modify the overrides file you created and re-apply it.

Making a configuration change

To make a configuration change to a hybrid runtime plane component, edit your overrides file and apply the changes with apigeectl.

For example, to change the replica count on the Message processor, follow these steps:

Open your overrides YAML file. Be sure to use the same overrides file that was used to install the hybrid runtime into the cluster.

Locate the runtime element in the file. For example:

...
runtime:
  nodeSelector:
    key: cloud.google.com/gke-nodepool
    value: apigee-runtime
  replicaCountMin: 1
  replicaCountMax: 2
...

Change the replica count properties as needed. For example:

...
runtime:
  nodeSelector:
    key: cloud.google.com/gke-nodepool
    value: apigee-runtime
  replicaCountMin: 2
  replicaCountMax: 4
...

Use apigeectl to apply the change to the cluster:
```
apigeectl apply -f ./my_overrides.yaml -c runtime
```
Use the -c option when you want to restrict the cluster update to one component. If you omit the -c flag, apigeectl applies all of the changes changes it finds in the overrides file. If that's what you want, then omit the -c flag when applying. If not, use -c to specify a component to update. See also Apply the configuration for a single component.

Which configuration properties can you modify?

You can find the complete list of configurable properties in the Configuration property reference. The reference only lists the properties you can modify; if you try to modify a property that's not in the reference, the change is ignored.

How to use the configuration reference

The Configuration property reference uses dot notation to describe configuration elements, where the first item is the top-level element name followed by properties and child properties. For example:

authz.image.pullPolicy

In the overrides file, the property are formatted in proper YAML. For the above example, the top-level authz element is left-indented and sub-element properties are indented under it. Also, YAML requires a colon at the end of each element and sub-element.

For example, to set the authz.image.pullPolicy property to Always, locate this YAML stanza in the overrides file and set it:

authz:
  image:
    pullPolicy: Always

For another example, the property cassandra.auth.admin.password (as it is listed in the Configuration property reference) is used to set the Cassandra admin password. To change it, locate the following YAML in the overrides file and set it:

cassandra:
  auth:
    admin:
      password: abc123

Remember, the Configuration property reference describes all of the properties that you can set on hybrid runtime plane components. Follow the pattern explained above to modify these elements in your overrides file before applying the changes to your cluster.

Using pre-defined example overrides files

When you first install hybrid runtime, Apigee recommends that you use one of the pre-configured example overrides files. These examples provide a complete set of configuration properties for specific installation scenarios, such as for setting up a production or test installation. All you need to do is provide appropriate values for the properties and apply the overrides file to your cluster. See Create an overrides file for more information.

About configuration defaults

Apigee maintains its default component configuration in the file hybrid_root_dir/config/values.yaml. Your overrides file(s) follows the same YAML structure as values.yaml.

An overrides file typically includes only a subset of the configuration properties found in values.yaml. Remember, not all properties are editable. When you apply a configuration to a cluster, your overrides are merged with the defaults to create the complete Kubernetes cluster configuration. See also Output the merged configuration.

The following code shows the default configuration for the mart component as found in values.yaml. Note that some values have defaults, while others such as sslCertPath and sslKeyPath do not. You must provide these missing values in your overrides file, as explained in the installation steps. If you want to change any of the default values, make sure they are editable by checking in the Configuration property reference.

...
mart:
  replicaCountMin: 2
  replicaCountMax: 4
  targetCPUUtilizationPercentage: 75
  terminationGracePeriodSeconds: 30
  sslCertPath:
  sslKeyPath:
  hostAlias:
  nodeSelector:
    key:
    value:
  revision: blue
  image:
    url: "google/apigee-mart-server"
    tag: "1.0.0"
    pullPolicy: IfNotPresent
  resources:
    requests:
      cpu: 500m
      memory: 512Mi
  initCheckCF:
    resources:
      requests:
        cpu: 10m
  livenessProbe:
    timeoutSeconds: 1
    failureThreshold: 12
    periodSeconds: 5
    initialDelaySeconds: 15
  readinessProbe:
    timeoutSeconds: 1
    successThreshold: 1
    failureThreshold: 2
    periodSeconds: 5
    initialDelaySeconds: 15
  metricsURL: "/v1/server/metrics"
  cwcAppend: |
...

If you want to modify a component's defaults and the component is not already in your overrides file, you can copy its YAML from values.yaml into your overrides file and modify it there.

Never edit values.yaml directly; always use an overrides file to specify your configuration properties.

Sample overrides files

Apigee provides a set of sample overrides files to help guide you in setting up your hybrid deployment. It's a good practice to copy and modify the overrides file that most closely matches your installation requirements.

The following samples are included in the directory hybrid_root_dir/examples:

Sample overrides files	Description
`overrides-small.yaml`	This sample is ideal for a getting started quickly. It uses the minimum recommended footprint to start the hybrid runtime components. This sample configuration relies as much as possible on default settings and values. All the minimum replicas are set 1.
`overrides-medium.yaml`	This sample is a good starting point for testing and QA environments. Individual components have been granted a higher level of resources to deal with additional traffic. Cassandra uses SSD disks for performance. In this environment, it is recommended that users install stateful and stateless components on separate nodes. See Configure dedicated nodes.
`overrides-large.yaml`	This sample is a good starting point for high performance environments such as pre-production and production. The sample includes properties for setting encryption keys, passwords, and others. Individual components have a minimum of two replicas.

Output the merged configuration

You can use the --dry-run flag with apigeectl to output the merged configuration file without actually applying it to your cluster. This option is useful for debugging an installation problem because it shows you exactly what will be applied to the cluster. It is also a good practice to output the configuration and store it in source control so that you have a reference of the resources installed and configured in the cluster.

For example:

apigeectl apply -f ./my_overrides.yaml --dry-run --print-yaml > apigee-hybrid.yaml

For more information, see apigeectl.

Create multiple overrides files as needed

You can create as many overrides files as you want, where each one serves a specific requirement. For example, you might have an overrides file that tunes your cluster for production, and another for creating a testing cluster. You can then maintain these files in your source control system.

Use the -f option with apigeectl to specify the location and name of an overrides file. For example:

apigeectl apply  -f ./test_env_override.yaml

For more information, see apigeectl.

Delete hybrid-specific runtime plane components

To delete the hybrid-specific runtime plane components from your cluster, use the apigeectl delete command. These components include synchronizer, mart, runtime, cassandra, and udca. Be sure to specify the same overrides file that you used to install the runtime components:

For example:

apigeectl delete -f ./my_overrides.yaml

You can use the apigeectl apply command to recreate a specific component or components:

apigeectl apply -c synchronizer -f ./my_overrides.yaml

For more information, see apigeectl.

Delete a specific component

If you only want to delete a specific component, use the -c option with apigeectl delete Be sure to specify the same overrides file you used to install the runtime components.

For example, to delete the Synchronizer component, use this command:

apigeectl delete -c synchronizer -f ./my_overrides.yaml

You can then use the apigeectl apply command to recreate the component:

apigeectl apply -c synchronizer -f ./my_overrides.yaml

For more information, see apigeectl.

Delete all components

To delete all of your cluster components hybrid, including those created by the apigeectl init command, use the apigeectl delete command with the --all flag. Be sure to specify the same overrides file that you used to install the runtime components:

For example:

apigeectl delete -f ./my_overrides.yaml --all

For more information, see apigeectl.