Kubernetes plugin for drone.io (for ARM/raspberry pi architecture)

A basic plugin that allows you to update the container for a Kubernetes deployment, on an agent using an arm CPU.

Usage

Each plugin usage requires the kubernetes_server, kubernetes_cert, and kubernetes_token to be provided. Details on how to get (and potentially set) those values can be found at the bottom of this guide.

Examples

This pipeline will update the my-deployment deployment with the image tagged DRONE_COMMIT_SHA:0:8

kind: pipeline
name: kubernetes-deploy

steps:
  - name: deploy
    image: matthewoden/drone-kubernetes-arm
    settings:
      - kubernetes_server: ${KUBERNETES_SERVER}
      - kubernetes_cert: ${KUBERNETES_CERT}
      - kubernetes_token: ${KUBERNETES_TOKEN}
      - deployment: my-deployment
      - repo: myorg/myrepo
      - container: my-container
      - tag: ${DRONE_COMMIT_SHA:0:8}

Deploying containers across several deployments, eg in a scheduler-worker setup. Make sure your container name in your manifest is the same for each pod.

kind: pipeline
name: kubernetes-deploy

steps:
  - name: deploy
    image: matthewoden/drone-kubernetes-arm
    settings:
      - kubernetes_server: ${KUBERNETES_SERVER}
      - kubernetes_cert: ${KUBERNETES_CERT}
      - kubernetes_token: ${KUBERNETES_TOKEN}
      - deployment: [server-deploy, worker-deploy]
      - repo: myorg/myrepo
      - container: my-container
      - tag: mytag

Deploying multiple containers within the same deployment.

kind: pipeline
name: kubernetes-deploy

steps:
  - name: deploy
    image: matthewoden/drone-kubernetes-arm
    settings:
      - kubernetes_server: ${KUBERNETES_SERVER}
      - kubernetes_cert: ${KUBERNETES_CERT}
      - kubernetes_token: ${KUBERNETES_TOKEN}
      - deployment: my-deployment
      - repo: myorg/myrepo
      - container: [container1, container2]
      - tag: mytag

NOTE: Combining multi container deployments across multiple deployments is not recommended

This more complex example demonstrates how to deploy to several environments based on the branch, in a app namespace

kind: pipeline
name: kubernetes-deploy

steps:
  - name: deploy-staging
    image: matthewoden/drone-kubernetes-arm
    settings:
      - kubernetes_server: ${KUBERNETES_SERVER_STAGING}
      - kubernetes_cert: ${KUBERNETES_CERT_STAGING}
      - kubernetes_token: ${KUBERNETES_TOKEN_STAGING}
      - deployment: my-deployment
      - repo: myorg/myrepo
      - container: my-container
      - namespace: app
      - tag: mytag
    when:
      branch: [staging]

  - name: deploy-prod
    image: matthewoden/drone-kubernetes-arm
    settings:
      - kubernetes_server: ${KUBERNETES_SERVER_PROD}
      - kubernetes_token: ${KUBERNETES_TOKEN_PROD}
      - deployment: my-deployment
      - repo: myorg/myrepo
      - container: my-container
      - namespace: app
      - tag: mytag
    when:
      - branch: [master]

Required fields

Each use of the plugin should provide a kubernetes server, cert, token and secret.

You can add these as env variables to your drone.yaml, or as secrets via the CLI:

    drone secret add
      --respository your-user/your-repo
      --name KUBERNETES_SERVER
      --data https://mykubernetesapiserver

    drone secret add
      --repository your-user/your-repo \
      --name KUBERNETES_CERT \
      --data <base64 encoded CA.crt>

    drone secret add
      --repository your-user/your-repo \
      --name KUBERNETES_TOKEN
      --data eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJrdWJ...

When using TLS Verification, ensure Server Certificate used by kubernetes API server is signed for your SERVER url (this could be a reason for failures if you use aliases for your kubernetes cluster)

How to get a token

Default Service Account

I recommend creating a deployment service account with RBAC (further below)

1. After deployment, inspect your pod for the name of your (k8s) secret with token and ca.crt

kubectl describe [ your pod name ] | grep SecretName | grep token

2. Get data from your (k8s) secret

kubectl get secret [ your default secret name ] -o yaml | egrep 'ca.crt:|token:'

3. Copy-paste contents of ca.crt into your drone's KUBERNETES_CERT secret
4. Decode base64 encoded token

echo [ your k8s base64 encoded token ] | base64 -d && echo''

5. Copy-paste decoded token into your drone's KUBERNETES_TOKEN secret

RBAC

When using a version of kubernetes with RBAC (role-based access control) enabled, you will not be able to use the default service account, since it does not have access to update deployments. Instead, you will need to create a custom service account with the appropriate permissions (Role and RoleBinding, or ClusterRole and ClusterRoleBinding if you need access across namespaces using the same service account).

As an example (for the web namespace):

apiVersion: v1
kind: ServiceAccount
metadata:
  name: drone-deploy
  namespace: web

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: drone-deploy
  namespace: web
rules:
  - apiGroups: ["extensions"]
    resources: ["deployments"]
    verbs: ["get", "list", "patch", "update"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: drone-deploy
  namespace: web
subjects:
  - kind: ServiceAccount
    name: drone-deploy
    namespace: web
roleRef:
  kind: Role
  name: drone-deploy
  apiGroup: rbac.authorization.k8s.io

Once the service account is created, you can extract the ca.cert and token parameters as mentioned for the default service account above:

kubectl -n web get secrets
# Substitute XXXXX below with the correct one from the above command
kubectl -n web get secret/drone-deploy-token-XXXXX -o yaml | egrep 'ca.crt:|token:'

Special thanks

Inspired by drone-helm.