CI/CD deployment tools for Kubernetes

This alpine-based docker image contains next tools:

• kubectl - Kubernetes CLI
• oc - OpenShift CLI
• istioctl - Istio cli
• gettext - so you can use envsubst to substitute environment variables in your CI/CD pipeline

Why should I use envsubst? You should never put secrets into your version control, so you might want to keep them in secret variables in your CI/CD system. You can use envsubst to substituted them correctly in your templates.

A CI/CD system usually sets a bunch of variables to the build environment. Below I'll show an example of GitLab CI variables set in the build environment.

• CI_PROJECT_NAME: my_awesome_project
• CI_BUILD_REF_SLUG: f1234d

Your app.yaml could look similar the one below:

...
- apiVersion: v1
  kind: DeploymentConfig
  metadata:
    labels:
      app: ${CI_PROJECT_NAME}
    name: sample
  spec:
    replicas: 1
    selector:
      app: ${CI_PROJECT_NAME}
      deployment: ${CI_BUILD_REF_SLUG}
...

After cat app.yaml | envsubst > app.yaml you'll notice the variables have been replaced with their actual values:

...
- apiVersion: v1
  kind: DeploymentConfig
  metadata:
    labels:
      app: my_awesome_project
    name: sample
  spec:
    replicas: 1
    selector:
      app: my_awesome_project
      deployment: f1234d
...

Below a sample job in an .gitlab-ci.yml file:

deploy:
  image: spaceonfire/k8s-deploy-tools
  stage: deploy
  before_script:
    - oc login "$KUBE_URL" --token="$KUBE_TOKEN" --insecure-skip-tls-verify
    - oc project "$KUBE_NAMESPACE" 2> /dev/null || oc new-project "$KUBE_NAMESPACE"
  script:
    - cat app.yaml | envsubst > app.yaml
    - oc apply -f app.yaml