Helmfile

Helmfile is a declarative spec for deploying Helm charts. It lets you…

• Keep a directory of chart value files and maintain changes in version control.
• Apply CI/CD to configuration changes.
• Periodically sync to avoid skew in environments.

To avoid upgrades for each iteration of Helm, the Helmfile executable delegates to Helm - as a result, Helm must be installed.

This page will offer some usage examples of deplying Kubedeploy chart with Helmfile. It's by no means a replacement for Helmfile documentation, for full reference of configuration values and Helmfile options, please visit the official Helmfile page.

Quick start

1. Install Helmfile or use it from container

2. Create helmfile.yaml configuration

---
repositories:
  - name: sysbee
    url: https://charts.sysbee.io/stable/sysbee

releases:
  - name: my-webserver
    namespace: apps
    chart: sysbee/kubedeploy
    disableValidationOnInstall: true
    version: 1.1.0
    installed: true

    values:
      - image:
          repository: nginx
          tag: latest

1. Deploy with helmfile

helmfile --file helmfile.yaml apply

Deploying multiple releases

From quickstart we might not get really great benefits while handling single deploymet. Where Helmfile shines is the managing multiple releases, and their dependencies, while helping you template repetitive values.

Deploy multiple applications with dependencies

---
repositories:
  - name: sysbee
    url: https://charts.sysbee.io/stable/sysbee

releases:
  - name: my-webserver
    namespace: apps
    chart: sysbee/kubedeploy
    version: 1.1.0
    installed: true

    values:
      - image:
          repository: nginx
          tag: latest

  - name: my-app
    namespace: apps
    chart: sysbee/kubedeploy
    version: 1.1.0
    installed: true

    needs:
      - my-webserver

    values:
      - image:
          repository: my-app
          tag: latest

Deploy command

helmfile --file helmfile.yaml apply --skip-needs=false

When making modification to our release values we can also do preview of changes prior to applying them directly to the cluster

Example

helmfile --file helmfile.yaml diff

Will output any changes in our releases

Templating releases

If we wish to follow the Best practices for multiple releases managed with Helmfile we can easily define all the best practices in release template, and reuse it in all our releases:

Release templating

---
repositories:
  - name: sysbee
    url: https://charts.sysbee.io/stable/sysbee

templates:
  default: &default
    namespace: apps
    chart: sysbee/kubedeploy
    version: 1.1.0
    installed: true
    valuesTemplate:
      - nameOverride: '{{`{{ .Release.Name }}`}}'
      - replicaCount: 3
      - podDisruptionBudget:
          enabled: true
      - topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: host
          whenUnsatisfiable: ScheduleAnyway
          labelSelector:
            matchLabels:
              app.kubernetes.io/instance: '{{`{{ .Release.Name }}`}}'

releases:
  - name: my-webserver
    <<: *default
    values:
      - replicaCount: 2
      - image:
          repository: nginx
          tag: latest

  - name: my-app
    <<: *default
    needs:
      - my-webserver
    values:
      - image:
          repository: my-app
          tag: latest

All releases referencing the default anchor will inherit settings from default template. We can then easily keep common configuration values in one place, and override them per release if we need to.

Using environment variables

Helmfile can use environment variables as inputs for chart values which can be pretty useful in defining variable values via CI/CD pipelines.

Users can define variables or secrets in CI/CD settings on GitHub or GitLab projects and then reference them in helmfile.yaml

Using environment variables

---
repositories:
  - name: sysbee
    url: https://charts.sysbee.io/stable/sysbee

releases:
  - name: my-webserver
    namespace: apps
    chart: sysbee/kubedeploy
    disableValidationOnInstall: true
    version: 1.1.0
    installed: true

    values:
      - image:
          repository: nginx
          tag: latest
      - extraSecrets:
          - name: app-secret
            type: Opaque
            data:
              username: {{ requiredEnv "NGINX_USERNAME" }}
              password: {{ requiredENV "NGINX_PASSWORD" }}

Let's export the env vars before running helmfile

export env vars

export NGINX_USERNAME=user
export NGINX_PASSWORD=supersecret

Deploy command

hemfile --file helmfile.yaml apply