Use a sidecar container in Kubernetes

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.

What's next