airshipctl/krm-functions/toolbox

Toolbox

This is KRM function written in go and uses the kyaml library for executing binaries inside container. It helps to run scripts in container as a airshipctl phase. The toolbox image has pre-installed sh shell,kubectl and calicoctl.

How to run your script as airshipctl phase

NOTE: All file paths in the following steps depend on the site you are working with and differ depending on the environment.

1. Create a phase document (kind: Phase)

    apiVersion: airshipit.org/v1alpha1
    kind: Phase
    metadata:
      name: kubectl-wait-node-ephemeral
      clusterName: ephemeral-cluster
    config:
      executorRef:
        apiVersion: airshipit.org/v1alpha1
        kind: GenericContainer
        name: kubectl-get-node
   

2. Create executor document (kind: GenericContainer). The executor use configRef to reference ConfigMap that will be generated using configMapGenerator. configRef must reference a Kubernetes ConfigMap with data key script with the script you want to execute. You can use kustomize configMapGenerator to create ConfigMaps (see example).

    apiVersion: airshipit.org/v1alpha1
    kind: GenericContainer
    metadata:
      name: kubectl-get-node
      labels:
        airshipit.org/deploy-k8s: "false"
    spec:
      type: krm
      image: localhost/toolbox
      hostNetwork: true
      envVars
        MY_ENV # airshipctl will populate this value from your current env, you can pass credentials like this
        MY_ENV_TWO="my-value"
    configRef:
      kind: ConfigMap
      name: kubectl-get-node
      apiVersion: v1
   

3. Add your script as a ConfigMap. Scripts inside container have access to site kubeconfig in ${KUBECONFIG} and to context of the cluster in ${KCTL_CONTEXT} environment variables.

    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: kubectl-get-node
    data:
      script: |
        #!/bin/sh
        calicoctl apply --context ${KTCL_CONTEXT} -f $RENDERED_BUNDLE_PATH
        kubectl apply --context ${KTCL_CONTEXT} -f $RENDERED_BUNDLE_PATH
   

   1. add kustomize resources
   2. include them into PhaseConfigBundle

4. Make sure it is added to the bundle:

   1. airshipctl phase render --source config -k ConfigMap find your configmap in the output
   2. airshipctl phase render --source config -k Phase find your phase in output
   3. airshipctl phase render --source config -k GenericContainer find your executor in output

5. Run your phase: airshipctl phase run kubectl-wait-node-ephemeral

Input bundle usage

The KRM function writes to filesystem input bundle specified in documentEntryPoint in phase declaration and imports the path to this bundle in RENDERED_BUNDLE_PATH environment variable. For example it can be used with calicoctl as calicoctl apply -f $RENDERED_BUNDLE_PATH Documents can be filtered by group, version and kind. You need to set RESOURCE_GROUP_FILTER, RESOURCE_VERSION_FILTER and/orRESOURCE_KIND_FILTER in executor definition to enable filtering.

Important notes

1. The script must write to STDOUT valid yaml or redirect output to STDERR otherwise phase will fail with mapping values are not allowed in this context
2. All shell scripts must begin with set -xe. This allows errors to be passed from the container to the airshipctl itself. Without this flags the container will never fail.