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GitLab CI template for Helmfile

This project implements a GitLab CI/CD template to deploy your application to a Kubernetes platform using helmfile.

Usage

This template can be used both as a CI/CD component or using the legacy include:project syntax.

Use as a CI/CD component

Add the following to your gitlab-ci.yml:

include:
  # 1: include the component
  - component: gitlab.com/to-be-continuous/helmfile/gitlab-ci-helmfile@3.2.4
    # 2: set/override component inputs
    inputs:
      # ⚠ this is only an example
      base-app-name: wonderapp
      review-enabled: true
      staging-enabled: true
      prod-enabled: true

Use as a CI/CD template (legacy)

Add the following to your gitlab-ci.yml:

include:
  # 1: include the template
  - project: 'to-be-continuous/helmfile'
    ref: '3.2.4'
    file: '/templates/gitlab-ci-helmfile.yml'

variables:
  # 2: set/override template variables
  # ⚠ this is only an example
  HELMFILE_BASE_APP_NAME: wonderapp
  HELMFILE_REVIEW_ENABLED: "true"
  HELMFILE_STAGING_ENABLED: "true"
  HELMFILE_PROD_ENABLED: "true"

Understand

This chapter introduces key notions and principle to understand how this template works.

Managed deployment environments

This template implements continuous delivery/continuous deployment using helmfile for projects hosted on Kubernetes platforms.

It allows you to manage automatic deployment & cleanup of standard predefined environments. Each environment can be enabled/disabled by configuration. If you're not satisfied with predefined environments and/or their associated Git workflow, you may implement you own environments and workflow, by reusing/extending the base (hidden) jobs. This is advanced usage and will not be covered by this documentation.

The following chapters present the managed predefined environments and their associated Git workflow.

Review environments

The template supports review environments: those are dynamic and ephemeral environments to deploy your ongoing developments (a.k.a. feature or topic branches).

When enabled, it deploys the result from upstream build stages to a dedicated and temporary environment. It is only active for non-production, non-integration branches.

It is a strict equivalent of GitLab's Review Apps feature.

It also comes with a cleanup job (accessible either from the environments page, or from the pipeline view).

Integration environment

If you're using a Git Workflow with an integration branch (such as Gitflow), the template supports an integration environment.

When enabled, it deploys the result from upstream build stages to a dedicated environment. It is only active for your integration branch (develop by default).

Production environments

Lastly, the template supports 2 environments associated to your production branch (main or master by default):

  • a staging environment (an iso-prod environment meant for testing and validation purpose),
  • the production environment.

You're free to enable whichever or both, and you can also choose your deployment-to-production policy:

  • continuous deployment: automatic deployment to production (when the upstream pipeline is successful),
  • continuous delivery: deployment to production can be triggered manually (when the upstream pipeline is successful).

Deployment context variables

In order to manage the various deployment environments, this template provides a couple of dynamic variables that you might use in your hook scripts and helmfile templates.

The environment variables are available in the helmfile template with the {{ env "<ENV_VAR_NAME>" }} directive.

environment variable template directive Description
$environment_name {{ env "environment_name" }} a generated application name to use for the current deployment environment (ex: myproject-review-fix-bug-12 or myproject-staging). This should be used as release name in the helmfile.yaml - details below
$environment_type {{ env "environment_type" }} the current deployment environment type (review, integration, staging or production)
$environment_url {{ env "environment_url" }} the environment URL (see also environment url management)
$environment_hostname {{ env "environment_hostname" }} the environment hostname, extracted from the environment URL
$kube_namespace {{ .Namespace }} the Kubernetes namespace currently used for deployment/cleanup

The $environment_type is also passed as --environment parameter to helmfile which allows you to inject a set of values specific to the environment type (see helmfile environment values).

💡 The docker image output variables passed by the Docker template (docker_image, docker_tag, ...) will also be available with the env directive in the helmfile template (e.g. {{ env "docker_tag" }}).

Example use in helmfile manifest

Below a helmfile.yaml example illustrating the use of environment variables:

environments:
  default:
  integration:
  review:
  production:
---
repositories:
  - name: mycharts
    url: https://repo.example.io/mycharts/stable
releases:
- name: {{ env "environment_name" | Default "myapp" }}
  chart: mycharts/webapp
  version: "1.2.0" 
  namespace: {{ .Namespace }}  
  values:
  - image:
      registry: {{ regexReplaceAll "^([^/]+)\\/([^:^@]+)(@|:|)(.*)$" (env "docker_image") "${1}" }}
      repository: {{ regexReplaceAll "^([^/]+)\\/([^:^@]+)(@|:|)(.*)$" (env "docker_image") "${2}" }}
      {{- if eq .Environment.Name "production" }}
      tag: {{ env "docker_tag" }}
      {{- else }}
      digest: {{ env "docker_digest" }}
      {{- end }}
    ingress:
      enabled: true
      hostname: {{ env "environment_hostname" }}

Generated environment name

The ${environment_name} variable is generated to designate each deployment environment with a unique and meaningful release and application name. By construction, it is suitable for inclusion in DNS, URLs, Kubernetes labels...

It is built from:

  • the application base name (defaults to $CI_PROJECT_NAME but can be overridden globally and/or per deployment environment - see configuration variables)
  • GitLab predefined $CI_ENVIRONMENT_SLUG variable (sluggified name, truncated to 24 characters)

The ${environment_name} variable is then evaluated as:

  • <app base name> for the production environment
  • <app base name>-$CI_ENVIRONMENT_SLUG for all other deployment environments
  • 💡 ${environment_name} can also be overriden per environment with the appropriate configuration variable

Examples (with an application's base name myapp):

$environment_type Branch $CI_ENVIRONMENT_SLUG $environment_name
review feat/blabla review-feat-bla-xmuzs6 myapp-review-feat-bla-xmuzs6
integration develop integration myapp-integration
staging main staging myapp-staging
production main production myapp

Deployment and cleanup scripts

The Helmfile template requires you to provide a helmfile.yaml file to deploy and delete the application.

The environment deployment is processed as follows:

  1. optionally executes the helmfile-pre-deploy.sh script in your project to perform specific environment pre-initialization (for e.g. create required services),
  2. helmfile apply with $environment_type as value for the --environment parameter,
  3. optionally executes the helmfile-post-deploy.sh script in your project to perform specific environment post-initialization stuff,

The environment deletion is processed as follows:

  1. optionally executes the helmfile-pre-delete.sh script in your project to perform specific environment pre-cleanup stuff,
  2. helmfile destroy with $environment_type as value for the --environment parameter,
  3. optionally executes the helmfile-post-delete.sh script in your project to perform specific environment post-cleanup (for e.g. delete bound services).

Using variables

You have to be aware that your helmfile state files and deployment (and cleanup) scripts have to be able to cope with various environments (review, integration, staging and production), each with different application names, exposed routes, settings, ... Most of the complexity can be handled by helmfile by using helmfile environments, environment variables, and templating. All environment variables are at your disposal within your helmfile templates:

The deployment context variable $environment_type is passed as helmfile environment and can be used to select environment values and customize releases per deployment environment type.

Environments URL management

The Helmfile template supports two ways of providing your environments url:

  • a static way: when the environments url can be determined in advance, probably because you're exposing your routes through a DNS you manage,
  • a dynamic way: when the url cannot be known before the deployment job is executed.

The static way can be implemented simply by setting the appropriate configuration variable(s) depending on the environment (see environments configuration chapters):

  • $HELMFILE_ENVIRONMENT_URL to define a default url pattern for all your envs,
  • $HELMFILE_REVIEW_ENVIRONMENT_URL, $HELMFILE_INTEG_ENVIRONMENT_URL, $HELMFILE_STAGING_ENVIRONMENT_URL and $HELMFILE_PROD_ENVIRONMENT_URL to override the default.

ℹ Each of those variables support a late variable expansion mechanism with the %{somevar} syntax, allowing you to use any dynamically evaluated variables such as ${environment_name}.

Example:

variables:
  HELMFILE_BASE_APP_NAME: "wonderapp"
  # global url for all environments
  HELMFILE_ENVIRONMENT_URL: "https://%{environment_name}.nonprod.acme.domain"
  # override for prod (late expansion of $HELMFILE_BASE_APP_NAME not needed here)
  HELMFILE_PROD_ENVIRONMENT_URL: "https://$HELMFILE_BASE_APP_NAME.acme.domain"
  # override for review (using separate resource paths)
  HELMFILE_REVIEW_ENVIRONMENT_URL: "https://wonderapp-review.nonprod.acme.domain/%{environment_name}"

To implement the dynamic way, your deployment script shall simply generate a environment_url.txt file in the working directory, containing only the dynamically generated url. When detected by the template, it will use it as the newly deployed environment url.

Deployment output variables

Each deployment job produces output variables that are propagated to downstream jobs (using dotenv artifacts):

  • $environment_type: set to the type of environment (review, integration, staging or production),
  • $environment_name: the application name (see below),
  • $environment_url: set to the environment URL (whether determined statically or dynamically).

Those variables may be freely used in downstream jobs (for instance to run acceptance tests against the latest deployed environment).

You may also add and propagate your own custom variables, by pushing them to the helmfile.env file in your deployment script.

Configuration reference

Secrets management

Here are some advices about your secrets (variables marked with a 🔒):

  1. Manage them as project or group CI/CD variables:
    • masked to prevent them from being inadvertently displayed in your job logs,
    • protected if you want to secure some secrets you don't want everyone in the project to have access to (for instance production secrets).
  2. In case a secret contains characters that prevent it from being masked, simply define its value as the Base64 encoded value prefixed with @b64@: it will then be possible to mask it and the template will automatically decode it prior to using it.
  3. Don't forget to escape special characters (ex: $ -> $$).

Global configuration

The Helm template uses some global configuration used throughout all jobs.

Input / Variable Description Default value
cli-image / HELMFILE_CLI_IMAGE The Docker image used to run helmfile
⚠ set the version required by your Kubernetes server
ghcr.io/helmfile/helmfile:latest
path / HELMFILE_PATH The path to your helmfile.yaml ./helmfile.yaml
scripts-dir / HELMFILE_SCRIPTS_DIR The folder where hook scripts are located . (root project dir)
kube-namespace / KUBE_NAMESPACE The default Kubernetes namespace to use "${CI_PROJECT_NAME}-${CI_PROJECT_ID}-${CI_ENVIRONMENT_SLUG}" (see GitLab doc)
KUBE_CONTEXT Defines the context to be used in KUBECONFIG. When using GitLab agents with the CI/CD workflow, the value should be like path/to/agent/project:agent-name. To use different agents per environment, define an environment-scoped CI/CD variable for each agent. none
🔒 HELMFILE_DEFAULT_KUBE_CONFIG The default kubeconfig to use (either content or file variable) $KUBECONFIG (thus supports the GitLab Kubernetes integration when enabled)
deploy-args / HELMFILE_DEPLOY_ARGS The helmfile command with options to deploy the application (without dynamic global parameters such as helmfile.yaml path and environment name) apply --wait
delete-args / HELMFILE_DELETE_ARGS The helmfile command with options to cleanup the application (without dynamic global parameters such as helmfile.yaml path and environment name) destroy
base-app-name / HELMFILE_BASE_APP_NAME Base application name $CI_PROJECT_NAME (see GitLab doc)
environment-url / HELMFILE_ENVIRONMENT_URL Default environments url (only define for static environment URLs declaration)
supports late variable expansion (ex: https://%{environment_name}.helm.acme.com)
none
🔒 HELMFILE_PGP_PRIVATE_KEY_FILE PGP Private key for decrypting helmfile secrets (optional) none
🔒 HELMFILE_PGP_PASSPHRASE Passphrase for PGP private key (optional) none
image-pull-secret-name / HELMFILE_IMAGE_PULL_SECRET_NAME Name of the docker-registry k8s secret that will be created if the special GitLab deploy token is available. gitlab-registry

Review environments configuration

Review environments are dynamic and ephemeral environments to deploy your ongoing developments (a.k.a. feature or topic branches).

They are disabled by default and can be enabled by setting the HELMFILE_REVIEW_ENABLED variable (see below).

Here are variables supported to configure review environments:

Input / Variable Description Default value
review-enabled / HELMFILE_REVIEW_ENABLED Set to true to enable review env none (disabled)
review-app-name / HELMFILE_REVIEW_APP_NAME Application name for review env "${HELMFILE_BASE_APP_NAME}-${CI_ENVIRONMENT_SLUG}" (ex: myproject-review-fix-bug-12)
review-environment-url / HELMFILE_REVIEW_ENVIRONMENT_URL The review environments url (only define for static environment URLs declaration and if different from default) $HELMFILE_ENVIRONMENT_URL
review-namespace / HELMFILE_REVIEW_NAMESPACE The Kubernetes namespace to use for review env (only define to override default) $KUBE_NAMESPACE
🔒 HELMFILE_REVIEW_KUBE_CONFIG Specific kubeconfig for review env (only define to override default) $HELMFILE_DEFAULT_KUBE_CONFIG
review-autostop-duration / HELMFILE_REVIEW_AUTOSTOP_DURATION The amount of time before GitLab will automatically stop review environments 4 hours

Integration environment configuration

The integration environment is the environment associated to your integration branch (develop by default).

It is disabled by default and can be enabled by setting the HELMFILE_INTEG_ENABLED variable (see below).

Here are variables supported to configure the integration environment:

Input / Variable Description Default value
integ-enabled / HELMFILE_INTEG_ENABLED Set to true to enable integration env none (disabled)
integ-app-name / HELMFILE_INTEG_APP_NAME Application name for integration env $HELMFILE_BASE_APP_NAME-integration
integ-environment-url / HELMFILE_INTEG_ENVIRONMENT_URL The integration environment url (only define for static environment URLs declaration and if different from default) $HELMFILE_ENVIRONMENT_URL
integ-namespace / HELMFILE_INTEG_NAMESPACE The Kubernetes namespace to use for integration env (only define to override default) $KUBE_NAMESPACE
🔒 HELMFILE_INTEG_KUBE_CONFIG Specific kubeconfig for integration env (only define to override default) $HELMFILE_DEFAULT_KUBE_CONFIG
integ-autostop-duration / HELMFILE_INTEG_AUTOSTOP_DURATION The amount of time before GitLab will automatically stop the integration env never

Staging environment configuration

The staging environment is an iso-prod environment meant for testing and validation purpose associated to your production branch (main or master by default).

It is disabled by default and can be enabled by setting the HELMFILE_STAGING_ENABLED variable (see below).

Here are variables supported to configure the staging environment:

Input / Variable Description Default value
staging-enabled / HELMFILE_STAGING_ENABLED Set to true to enable staging env none (disabled)
staging-app-name / HELMFILE_STAGING_APP_NAME Application name for staging env $HELMFILE_BASE_APP_NAME-staging
staging-environment-url / HELMFILE_STAGING_ENVIRONMENT_URL The staging environment url (only define for static environment URLs declaration and if different from default) $HELMFILE_ENVIRONMENT_URL
staging-namespace / HELMFILE_STAGING_NAMESPACE The Kubernetes namespace to use for staging env (only define to override default) $KUBE_NAMESPACE
🔒 HELMFILE_STAGING_KUBE_CONFIG Specific kubeconfig for staging env (only define to override default) $HELMFILE_DEFAULT_KUBE_CONFIG
staging-autostop-duration / HELMFILE_STAGING_AUTOSTOP_DURATION The amount of time before GitLab will automatically stop the staging env never

Production environment configuration

The production environment is the final deployment environment associated with your production branch (main or master by default).

It is enabled by default and can be disabled by setting the HELMFILE_PROD_DISABLED variable (see below).

Here are variables supported to configure the production environment:

Input / Variable Description Default value
HELMFILE_PROD_DISABLED Set to true to disable production env none (disabled)
prod-app-name / HELMFILE_PROD_APP_NAME Application name for production env $HELMFILE_BASE_APP_NAME
prod-environment-url / HELMFILE_PROD_ENVIRONMENT_URL The production environment url (only define for static environment URLs declaration and if different from default) $HELMFILE_ENVIRONMENT_URL
prod-namespace / HELMFILE_PROD_NAMESPACE The Kubernetes namespace to use for production env (only define to override default) $KUBE_NAMESPACE
🔒 HELMFILE_PROD_KUBE_CONFIG Specific kubeconfig for production env (only define to override default) $HELMFILE_DEFAULT_KUBE_CONFIG
prod-deploy-strategy / HELMFILE_PROD_DEPLOY_STRATEGY Defines the deployment to production strategy. One of manual (i.e. one-click) or auto. manual

helmfile-lint job

This job runs a helm lint across all of the charts/releases in the helmfile manifest and uses the following variables:

Input / Variable Description Default value
lint-enabled / HELMFILE_LINT_ENABLED Set to true to enable Helmfile lint none (disabled)
lint-args / HELMFILE_LINT_ARGS The helmfile command with options to trigger the analysis lint

helmfile-test job

This job runs Helm tests against the specified releases in the helmfile manifest.

It is disabled by default and can be enabled by setting the HELMFILE_TEST_ENABLED variable (see below).

It uses the following variables:

Input / Variable Description Default value
test-enabled / HELMFILE_TEST_ENABLED Set to true to enable Helm test none (disabled)
test-args / HELMFILE_TEST_ARGS The helmfile command with options
to perform acceptance test (without dynamic global arguments such as the helmfile.yaml path, namespace and environment name) test

Variants

Vault variant

This variant allows delegating your secrets management to a Vault server.

Configuration

In order to be able to communicate with the Vault server, the variant requires the additional configuration parameters:

Input / Variable Description Default value
TBC_VAULT_IMAGE The Vault Secrets Provider image to use (can be overridden) registry.gitlab.com/to-be-continuous/tools/vault-secrets-provider:latest
vault-base-url / VAULT_BASE_URL The Vault server base API url none
vault-oidc-aud / VAULT_OIDC_AUD The aud claim for the JWT $CI_SERVER_URL
🔒 VAULT_ROLE_ID The AppRole RoleID must be defined
🔒 VAULT_SECRET_ID The AppRole SecretID must be defined

Usage

Then you may retrieve any of your secret(s) from Vault using the following syntax:

@url@http://vault-secrets-provider/api/secrets/{secret_path}?field={field}

With:

Parameter Description
secret_path (path parameter) this is your secret location in the Vault server
field (query parameter) parameter to access a single basic field from the secret JSON payload

Example

include:
  # main template
  - component: gitlab.com/to-be-continuous/helmfile/gitlab-ci-helmfile@3.2.4
  # Vault variant
  - component: gitlab.com/to-be-continuous/helmfile/gitlab-ci-helmfile-vault@3.2.4
    inputs:
      # audience claim for JWT
      vault-oidc-aud: "https://vault.acme.host"
      vault-base-url: "https://vault.acme.host/v1"
      # $VAULT_ROLE_ID and $VAULT_SECRET_ID defined as a secret CI/CD variable

variables:
  # Secrets managed by Vault
  HELMFILE_DEFAULT_KUBE_CONFIG: "@url@http://vault-secrets-provider/api/secrets/b7ecb6ebabc231/my-app/helmfile/noprod?field=kube_config"
  HELMFILE_PROD_KUBE_CONFIG: "@url@http://vault-secrets-provider/api/secrets/b7ecb6ebabc231/my-app/helmfile/prod?field=kube_config"