# GitLab Container Registry for CI/CD and Seamless Deployment

GitLab is an excellent SaaS tool for storing your code and automating workflows. If you have a managed Kubernetes cluster, you can also use GitLab as the container registry and the CI/CD platform.

## Create Secret

First, you need to create a permanent `Access Token` from your GitLab repository or group that will have access to all the child repositories and the container registry. This token will be used by `kubelet` to pull images from the GitLab-managed container registry. The secret creation will look like the following.

```bash
kubectl create secret docker-registry gitlab-token-auth \
   --docker-server=https://registry.gitlab.com \
   --docker-username=kubelet \
   --docker-password=1234zxcv0987
```

## CI/CD Pipeline

If you trigger a GitLab workflow inside GitLab-hosted runners, the workflow will have the privilege to push container images into the same code repository. Built-in variables like `CI_REGISTRY_USER`, `CI_REGISTRY_PASSWORD`, and `CI_REGISTRY_IMAGE` will be automatically populated during the pipeline run. Here is the code snippet that needs to be added to push the newly built image into Gitlab's container registry.

```yaml
push:
  image: docker:24
  services:
    - docker:24-dind
  stage: push
  script:
    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
    - docker build . -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
```

## Deployment

Once the image is pushed into Gitlab registry, you can use the previosly created `Secret` to pull the image into Kubernetes and run it. You will need to patch your deployment to include the `imagePullSecrets`.

```yaml
spec:
  metadata:
    spec:
      containers:
      - name: app
        image: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      imagePullSecrets:
      - name: gitlab-token-auth
```