Customizing the Replicated SDK

This topic describes various ways to customize the Replicated SDK, including customizing RBAC, setting environment variables, and adding tolerations.

Customize RBAC for the SDK

This section describes role-based access control (RBAC) for the Replicated SDK, including the default RBAC, minimum RBAC requirements, and how to install the SDK with custom RBAC.

Default RBAC

The SDK creates default Role, RoleBinding, and ServiceAccount objects during installation. The default Role allows the SDK to get, list, and watch all resources in the namespace, to create Secrets, and to update the replicated and replicated-instance-report Secrets:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    {{- include "replicated.labels" . | nindent 4 }}
  name: replicated-role
rules:
- apiGroups:
  - '*'
  resources:
  - '*'
  verbs:
  - 'get'
  - 'list'
  - 'watch'
- apiGroups:
  - ''
  resources:
  - 'secrets'
  verbs:
  - 'create'
- apiGroups:
  - ''
  resources:
  - 'secrets'
  verbs:
  - 'update'
  resourceNames:
  - replicated
  - replicated-instance-report
  - replicated-custom-app-metrics-report

Minimum RBAC Requirements

The SDK requires the following minimum RBAC permissions:

• Create Secrets.

• Get and update Secrets named replicated, replicated-instance-report, and replicated-custom-app-metrics-report.

• The SDK requires the following minimum RBAC permissions for status informers:

  • If you defined custom status informers, then the SDK must have permissions to get, list, and watch all the resources listed in the replicated.statusInformers array in your Helm chart values.yaml file.
  • If you did not define custom status informers, then the SDK must have permissions to get, list, and watch the following resources:
    • Deployments
    • Daemonsets
    • Ingresses
    • PersistentVolumeClaims
    • Statefulsets
    • Services
  • For any Ingress resources used as status informers, the SDK requires get permissions for the Service resources listed in the backend.Service.Name field of the Ingress resource.
  • For any Daemonset and Statefulset resources used as status informers, the SDK requires list permissions for pods in the namespace.
  • For any Service resources used as status informers, the SDK requires get permissions for Endpoint resources with the same name as the service.

  The Replicated Vendor Portal uses status informers to provide application status data. For more information, see Helm Installations in Enabling and Understanding Application Status.

Install the SDK with Custom RBAC

Custom ServiceAccount

To use the SDK with custom RBAC permissions, provide the name for a custom ServiceAccount object during installation. When a service account is provided, the SDK uses the RBAC permissions granted to the service account and does not create the default Role, RoleBinding, or ServiceAccount objects.

To install the SDK with custom RBAC:

1. Create custom Role, RoleBinding, and ServiceAccount objects. The Role must meet the minimum requirements described in Minimum RBAC Requirements above.
2. During installation, provide the name of the service account that you created by including --set replicated.serviceAccountName=CUSTOM_SERVICEACCOUNT_NAME.

Example:

helm install wordpress oci://registry.replicated.com/my-app/beta/wordpress --set replicated.serviceAccountName=mycustomserviceaccount

For more information about installing with Helm, see Installing with Helm.

Custom ClusterRole

To use the SDK with an existing ClusterRole, provide the name for a custom ClusterRole object during installation. When a cluster role is provided, the SDK uses the RBAC permissions granted to the cluster role and does not create the default RoleBinding. Instead, the SDK creates a ClusterRoleBinding as well as a ServiceAccount object.

To install the SDK with a custom ClusterRole:

1. Create a custom ClusterRole object. The ClusterRole must meet at least the minimum requirements described in Minimum RBAC Requirements above. However, it can also provide additional permissions that can be used by the SDK, such as listing cluster Nodes.
2. During installation, provide the name of the cluster role that you created by including --set replicated.clusterRole=CUSTOM_CLUSTERROLE_NAME.

Example:

helm install wordpress oci://registry.replicated.com/my-app/beta/wordpress --set replicated.clusterRole=mycustomclusterrole

For more information about installing with Helm, see Installing with Helm.

Set Environment Variables

The Replicated SDK provides a replicated.extraEnv value that allows users to set additional environment variables for the deployment that are not exposed as Helm values.

This ensures that users can set the environment variables that they require without the SDK Helm chart needing to be modified to expose the values. For example, if the SDK is running behind an HTTP proxy server, then the user could set HTTP_PROXY or HTTPS_PROXY environment variables to provide the hostname or IP address of their proxy server.

To add environment variables to the Replicated SDK deployment, include the replicated.extraEnv array in your Helm chart values.yaml file. The replicated.extraEnv array accepts a list of environment variables in the following format:

# Helm chart values.yaml

replicated:
  extraEnv:
  - name: ENV_VAR_NAME
    value: ENV_VAR_VALUE

note

If the HTTP_PROXY, HTTPS_PROXY, and NO_PROXY variables are configured with the kots install command, these variables will also be set automatically in the Replicated SDK.

Example:

# Helm chart values.yaml

replicated:
  extraEnv:
  - name: MY_ENV_VAR
    value: my-value
  - name: MY_ENV_VAR_2
    value: my-value-2  

Custom Certificate Authority

When installing the Replicated SDK behind a proxy server that terminates TLS and injects a custom certificate, you must provide the CA to the SDK. This can be done by storing the CA in a ConfigMap or a Secret prior to installation and providing appropriate values during installation.

Using a ConfigMap

To use a CA stored in a ConfigMap:

1. Create a ConfigMap and the CA as the data value. Note that name of the ConfigMap and data key can be anything.

   kubectl -n <NAMESPACE> create configmap private-ca --from-file=ca.crt=./ca.crt
2. Add the name of the config map to the values file:

   replicated:
     privateCAConfigmap: private-ca

note

If the --private-ca-configmap flag is used with the kots install command, this value will be populated in the Replicated SDK automatically.

Using a Secret

To use a CA stored in a Secret:

1. Create a Secret and the CA as a data value. Note that the name of the Secret and the key can be anything.

   kubectl -n <NAMESPACE> create secret generic private-ca --from-file=ca.crt=./ca.crt
2. Add the name of the secret and the key to the values file:

   replicated:
     privateCASecret:
       name: private-ca
       key: ca.crt

Add Tolerations

The Replicated SDK provides a replicated.tolerations value that allows users to add custom tolerations to the deployment. For more information about tolerations, see Taints and Tolerations in the Kubernetes documentation.

To add tolerations to the Replicated SDK deployment, include the replicated.tolerations array in your Helm chart values.yaml file. The replicated.tolerations array accepts a list of tolerations in the following format:

# Helm chart values.yaml

replicated:
  tolerations:
  - key: "key"
    operator: "Equal"
    value: "value"
    effect: "NoSchedule"

Add Affinity

The Replicated SDK provides a replicated.affinity value that allows users to add custom affinity to the deployment. For more information about affinity, see Affinity and anti-affinity in the Kubernetes documentation.

To add affinity to the Replicated SDK deployment, include the replicated.affinity map in your Helm chart values.yaml file. The replicated.affinity map accepts a standard Kubernets affinity object in the following format:

# Helm chart values.yaml

replicated:
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: production/node-pool
            operator: In
            values:
            - private-node-pool