Gitlab CI/CD: deploy docker image to existing kubernetes cluster

Question

I have node.js application that I need to deploy to exising kubernetes cluster.

The cluster is setup using kops on AWS.

I have created .gitlab-ci.yml file for building docker images.

So, whenever a change is pushed to either master or develop branch. It will build the docker image.

Now, I have to deploy it to exisitng kubernetes cluster. I have already followed steps mentioned here to add existing cluster.

For now, I am using shared runner.

How can I integrate kubernetes deployment after image is built with gitlab ci/cd to deploy on aws (cluster is created with kops)?

For registry I am using gitlab's container registry not docker hub.

I have tried below gitlab-ci.yaml file,

gitlab-ci.yaml

stages:
  - docker-build
  - deploy

docker-build-master:
  image: docker:latest
  stage: docker-build
  services:
    - docker:dind
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  script:
    - docker build --pull -t "$CI_REGISTRY_IMAGE:prod" .
    - docker push "$CI_REGISTRY_IMAGE:prod"
  only:
    - master

deploy-prod:
  stage: deploy
  image: roffe/kubectl
  script:
    - kubectl apply -f scheduler-deployment.yaml
  only:
    - master


docker-build-dev:
  image: docker:latest
  stage: docker-build
  services:
    - docker:dind
  before_script:
    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
  script:
    - docker build --pull -t "$CI_REGISTRY_IMAGE:dev" .
    - docker push "$CI_REGISTRY_IMAGE:dev"
  only:
    - develop

I am getting below error.

Executing "step_script" stage of the job script
00:01
Using docker image sha256:c8d24d490701efec4c8d544978b3e4ecc4855475a221b002a8f9e5e473398805 for roffe/kubectl with digest roffe/kubectl@sha256:ba13f8ffc55c83a7ca98a6e1337689fad8a5df418cb160fa1a741c80f42979bf ...
$ kubectl apply -f scheduler-deployment.yaml
error: unable to recognize "scheduler-deployment.yaml": Get http://localhost:8080/api?timeout=32s: dial tcp [::1]:8080: connect: connection refused
Cleaning up file based variables
00:00
ERROR: Job failed: exit code 1

File scheduler-deployment.yaml is a valid yaml file and it works when I apply manually.

Below is the deployment file.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: sheduler-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: scheduler
  template:
    metadata:
      labels:
        app: scheduler
    spec:
      containers:
        - name: scheduler
          image: registry.gitlab.com/user/schedulingapis:dev
          env:
            - name: REDIS_HOST
              value: "redis://redis-master "
            - name: RABBITMQ_HOST
              value: "amqp://rabbitmq"
      imagePullSecrets:
        - name: registry-credentials

If someone has any better idea to automate deployment to a k8s cluster with gitlab.

Pease do suggest. Any link or reference will also work.

Answer 1

Your error is most likely from referencing the wrong directory in your script block of your job.

When GitLab executes your job in a container, it mounts the project directory to the /builds directory in the container. You can reference this either by specifying /builds/scheduler-deployment.yaml or by using the predefined environment variable $CI_PROJECT_DIR with $CI_PROJECT_DIR/scheduler-deployment.yaml.