Overview

Helm is a package manager for Kubernetes.

An Helm Chart provides a set of parametrable Kubernetes Resource (using a Go templating engine) and allows versionning, rollbacks, a reusability.

Installation

To enable this tool, add this to your vars.yml:

---
tools:
  - helm

Examples

Helm can be called within a Bash manifest, in a bundle to deploy a Chart or generating a template manifest.

FluxCD Helm Operator

This pipeline will install the FluxCD Helm Operator:

vars.yml:

---
tools:
  - helm

packages:
  - name: helm-operator
    kind: bundle

bundles/helm-operator/10-namespace.yml:

---
apiVersion: v1
kind: Namespace
metadata:
  name: fluxcd

bundles/helm-operator/20-helm-dependencies.sh:

#!/bin/bash

set -eux

helm repo add fluxcd https://charts.fluxcd.io
helm repo update

kubectl apply -f https://raw.githubusercontent.com/fluxcd/helm-operator/1.2.0/deploy/crds.yaml

helm upgrade -i helm-operator fluxcd/helm-operator --wait \
  --namespace fluxcd \
  --set helm.versions=v3 \
  --set git.timeout=300s

Application generation

This pipeline will generate a manifest for the Nginx Ingress Controller to be deployed with kapp using helm as a template engine:

vars.yml:

---
tools:
  - helm

packages:
  - name: generate-nginx-ingress
    kind: bundle
  - name: nginx-ingress
    kind: application

bundles/generate-nginx-ingress/make-app.sh:

#!/bin/bash

set -eux

helm repo add nginx https://kubernetes.github.io/ingress-nginx
helm repo update

helm template helm-operator nginx/ingress-nginx > ./applications/nginx-ingress/manifest.yml

applications/nginx-ingress/README.md:

# Nginx Ingress Controller

This application will be generated by the bundle `generate-nginx-ingress`.

NB: the applications/nginx-ingress/ folder MUST exist. You can put a file .gitkeep inside, but it is recommended to at least add a README.md for documentation purposes.