Use a sidecar container in Kubernetes

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If your database runs in a Kubernetes cluster, then you can add sidecar containers to your database cluster using the AlloyDB Omni Kubernetes operator. AlloyDB Omni operator sidecar containers are regular Kubernetes containers that run independently alongside the main application container within the same Pod. You can use these sidecar containers to serve requests for application monitoring, logging, and tracing.

AlloyDB Omni operator sidecar containers are distinct from Kubernetes built-in sidecar containers.

To manually add a sidecar container to an existing AlloyDB Omni installation, you create a sidecar custom resource (CR) and add it to your database cluster.

Create a sidecar CR

  1. Apply the following manifest:

    apiVersion: alloydbomni.dbadmin.goog/v1 kind: Sidecar metadata:  name: SIDECAR_CR_NAME spec:  sidecars:  - image: CONTAINER_IMAGE  command: ["CONTAINER_COMMAND"]  args: ["CONTAINER_ARGS"]  name: CONTAINER_NAME

    Replace the following variables:

    • SIDECAR_CR_NAME: the name for your sidecar container.
    • CONTAINER_IMAGE: the name of the image file to run in your sidecar container. For example, busybox.
    • CONTAINER_COMMAND: the command for the container that runs in the Pod. The command can be a list of quoted strings. For more information, see Define a command and arguments when you create a Pod.
    • CONTAINER_ARGS: arguments for CONTAINER_COMMAND.
    • CONTAINER_NAME: the name of the container. You can have multiple containers in the same sidecar CR, and each container has a different container name, image, command, and arguments.

  2. To verify that the sidecar CR is created, run the following command:

    kubectl describe Sidecar/SIDECAR_CR_NAME

    The output is similar to the following:

    Name: SIDECAR_CR_NAME Labels: <none> Annotations: <none> API Version: alloydbomni.dbadmin.goog/v1 Kind: Sidecar Metadata:  Creation Timestamp: 2024-04-15T21:49:00Z  Finalizers:  sidecars.dbadmin.goog/finalizer  Generation: 2  Resource Version: 2561336  UID: e57f2e13-20c5-4905-b13b-39203bab36b4 Spec:  Sidecars:  Args:  CONTAINER_ARGS  Command:  CONTAINER_COMMAND  Image: CONTAINER_IMAGE  Name: CONTAINER_NAME  Resources: Status:  Observed Generation: 2  Reconciled: true Events: <none>

Register a sidecar container

To register the sidecar container name to your database cluster, use the following command to apply the updated specification:

kubectl patch dbclusters.alloydbomni.dbadmin.goog DB_CLUSTER_NAME -p '{"spec":{"primarySpec":{"sidecarRef":{"name":"SIDECAR_CR_NAME"}}}}' --type=merge

Replace the following variables:

  • DB_CLUSTER_NAME: the name of your database cluster.
  • SIDECAR_CR_NAME: the name for your sidecar container.

Access logs from a sidecar container

  1. Create, or modify an existing, sidecar container so that spec.sidecars.volumeMounts.name is set to obsdisk and spec.sidecars.volumeMounts.mountPath to a path visible within the sidecar container.

     apiVersion: alloydbomni.dbadmin.goog/v1  kind: Sidecar  metadata:  name: SIDECAR_CR_NAME  spec:  sidecars:  - image: CONTAINER_IMAGE  command: ["CONTAINER_COMMAND"]  args: ["CONTAINER_ARGS"]  name: CONTAINER_NAME  volumeMounts:  - name: obsdisk  mountPath: LOGS_PATH

    Replace the following:

    • SIDECAR_CR_NAME: the name for your sidecar container.
    • CONTAINER_IMAGE: the name of the image file to run in your sidecar container. For example, busybox.
    • CONTAINER_COMMAND: the command for the container that runs in the Pod. The command can be a list of quoted strings. For more information, see Define a command and arguments when you create a Pod.
    • CONTAINER_ARGS: the arguments for CONTAINER_COMMAND.
    • CONTAINER_NAME: the name of the container. You can have multiple containers in the same sidecar CR, and each container has a different container name, image, command, and arguments.
    • LOGS_PATH: the path within the sidecar container that AlloyDB Omni should output logs to.

  2. Register your new, or modified, sidecar container.

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