Shell Operator

Table of Contents

• Shell Operator
  • Table of Contents
  • Overview
  • How to use
    • Build the docker image
    • Create an overlay
    • ACM Overview
  • Disclaimer

Overview

This repository follows ACM trait pattern with examples to be deployed onto Google Distributed Cloud Conencted Clusters. Namely there are 3 examples that show how shell operator can be used to automate based on kubernete events occuring in the cluster.

• Pod Affinity for VMs:
  • In a specific given scenario where podAffinity is not being met, ensure VM(s) are migrated to the desired affinity that is required. In this example the vm called aligned-vm through shell-operator will be further rensured to be deployed onto the same node as robin-master. Review example, example2 for more details.

  scheduling:
    affinity:
      podAffinity:
        preferredDuringSchedulingIgnoredDuringExecution:
          - podAffinityTerm:
              labelSelector:
                matchLabels:
                  app: robin-master
              namespaces:
                - vm-workloads
                - robinio
              topologyKey: kubernetes.io/hostname
            weight: 100

• Load balancing VMs: In a specific given scenario where all VMs land on 1 node, ensure VM(s) are migrated over to other nodes for proper load balancing. In this example if 3 VM's [vm1,vm2,vm3] land onto 1 node, then VM Migration will take place. Review example for more details.
• Webhooks: Simiarly to OPA/Gatekeeper, here is an example network guardrail to stop users from deploy a bad network resource on to the cluster.Review example for more details.

How to use

Build the docker image

cd build

docker build -t gcr.io/PROJECT_NAME/shell-operator:TAG_NAME .

docker push gcr.io/PROJECT_NAME/shell-operator:TAG_NAME

Create an overlay

Create the kustomization.yaml file, replacing the patch value with the docker image path built in the previous step.

tree

.
├── overlays
│   └── shell-operator
│       └── kustomization.yaml

cat overlays/shell-operator/kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- https://gitlab.com/gcp-solutions-public/retail-edge/available-cluster-traits/shell-operator-trait.git/config

patches:
- patch: |-
    - op: replace
      path: /spec/template/spec/containers/0/image
      value: gcr.io/PROJECT_NAME/shell-operator:TAG_NAME
  target:
    group: apps
    kind: Deployment
    name: shell-operator
    version: v1

Apply the following RootSync, changing the dir to match where you saved the overlay.

apiVersion: configsync.gke.io/v1beta1
kind: RootSync
metadata:
  name: shell-operator-trait-sync
  namespace: config-management-system
spec:
  sourceFormat: unstructured
  git:
    auth: "token"
    branch: "main"
    dir: "/config/clusters/CLUSTER_NAME/overlays/shell-operator"
    repo: "https://path/to/your/repo.git"
    secretRef:
      name: git-creds
  override:
    enableShellInRendering: true

After this is applied, this should deploy shell-operator with the said examples.

ACM Overview

See our documentation for how to use each subdirectory.

Disclaimer

This project is not an official Google project. It is not supported by Google and Google specifically disclaims all warranties as to its quality, merchantability, or fitness for a particular purpose.