Kubernetes (k8s) + Helm + GitLab CI / CD. Properly deployed

In this article I want to tell how to deploy applications in different environments. In this example, we will deploy to: “Test” and “Production”. Of course, you can add any media.

For application deployment I use HELM. It allows flexible configuration management. What you can see below. It is assumed that you already have a tuned runner with helm and you know and know how to work with HELM.

Example file: .gitlab-ci.yml
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.base_deploy: &base_deploy stage: deploy script: - PROJECT_NAME="${CI_PROJECT_NAME}-${CI_ENVIRONMENT_SLUG}" - helm --namespace ${CI_ENVIRONMENT_SLUG} upgrade -i ${PROJECT_NAME} helm --set "global.env=${CI_ENVIRONMENT_SLUG}"; stages: - deploy Deploy to Test: <<: *base_deploy environment: name: test Deploy to Production: <<: *base_deploy environment: name: production when: manual 

Here it is worth paying attention to the fact that, depending on the environment, we are passing a variable: “test” or “production”.

We also form the name of the project taking into account the name of the variable, so that helm understands that these are different projects (helm ls).

Next, we pass this variable (environment) to the HELM as: “global.env”.

For the above example, helm should be in the same folder in your repository.

Now let's look at an example of how to use the environment variable in HELM Chart.

Create the following values.yaml :

 replicas: test: 1 production: 3 domain: test: test.domain.com production: production.domain.com resources: requests: cpu: _default: 50m production: 50m memory: _default: 256Mi production: 10Mi limits: memory: _default: 1Gi production: 1Gi cpu: _default: 1000m 

Here you can see that for different environments we specify different settings.
For convenience, you can specify the default settings.

Another example for ingress.yaml:

 apiVersion: extensions/v1beta1 kind: Ingress metadata: name: {{ .Chart.Name }} spec: rules: - host: {{ pluck .Values.global.env .Values.domain | first | default .Values.domain._default }} http: paths: - path: / backend: serviceName: {{ .Chart.Name }} servicePort: 80 

You can always check how your Chart is going, with the command:

 helm template ./helm --set "global.env=test" helm template ./helm --set "global.env=production" 

You can also deploy your code to different nodes depending on the environment.

Example:

 {{ if eq .Values.global.env "test" }} nodeSelector: nodetype: testnodes {{ else if eq .Values.global.env "production" }} nodeSelector: nodetype: productionnodes {{ else }} 

Thanks to all. Deployte right.