Helm Dependency Updater

This project resolves the problem of missing recursive dependency updates in Helm charts. It is a simple tool that can be used to update the dependencies of a Helm chart recursively. Charts from Registry already have their subcharts included, but if you use local file references file:// you need to update subcharts recursivly if you have more than one hierarchy level of dependencies.

There is an open issue and PR in the Helm project to add this functionality to Helm itself. Until this is resolved, this tool can be used to update the dependencies of a Helm chart recursively. It will be part of the Milestone 3.13.0 which is released on 13th of September 2023.

Install

wget -qO- "https://github.com/signavio/k8s-helm-dep-updater/releases/latest/download/k8s-helm-dep-updater_$(uname -s)_$(uname -m).tar.gz" | tar -C /tmp -xzf- k8s-helm-dep-updater
sudo mv /tmp/k8s-helm-dep-updater /usr/local/bin/k8s-helm-dep-updater

Install Helm Plugin

helm plugin install https://github.com/signavio/k8s-helm-dep-updater.git

Argocd Integration

To activate the helm dep updater we use downloader plugin to activate it. dummy can be anything. Most importantly with the deps:// prefix you can activate the downloader plugin.

project: default
source:
  repoURL: 'https://github.com/signavio/k8s-helm-dep-updater'
  path: charts/umbrella
  targetRevision: main
  helm:
    valueFiles:
      - 'deps://dummy'
destination:
  server: 'https://kubernetes.default.svc'
  namespace: default

To add the plugin to argocd, those are the relevant lines:

repoServer:
  initContainers:
    - name: download-tools
      image: alpine:3
      command: [sh, -c]
      args:
        - |
          mkdir -p /custom-tools/helm-plugins/helm-dep-updater
          wget -qO- "https://github.com/signavio/k8s-helm-dep-updater/releases/latest/download/k8s-helm-dep-updater.tar.gz" | tar -C /custom-tools/helm-plugins/helm-dep-updater -xzf-;
          wget -qO- "https://github.com/signavio/k8s-helm-dep-updater/releases/latest/download/k8s-helm-dep-updater_$(uname -s)_$(uname -m).tar.gz" | tar -C /custom-tools/ -xzf- k8s-helm-dep-updater
    volumeMounts:
      - mountPath: /custom-tools
        name: custom-tools
  env:
  - name: HELM_PLUGINS
    value: /custom-tools/helm-plugins
  # optionally if you want to login to ECR before fetching the charts
  # it expects a comma separated list of secret names
  - name: HELM_DEPS_SECRET_NAMES
    value: helm-ecr-staging,helm-ecr-production
  volumeMounts:
    - mountPath: /custom-tools
      name: custom-tools
    - mountPath: /usr/local/bin/k8s-helm-dep-updater
      name: custom-tools
      subPath: k8s-helm-dep-updater

Usage

Environment Variables

Environment Name	Default Value	Description
HELM_DEPS_SECRET_NAMES	""	Comma-separated list of registries to update.
HELM_DEPS_SECRET_NAMES_REPO_ADD	""	DEPRECATED: Comma-separated list of registries using 'helm repo add'.
HELM_DEPS_SKIP_REPO_OVERWRITE	false	Skips adding the repository if it already exists, useful during testing.
HELM_DEPS_SKIP_REFRESH	false	Skips repository update for sub-dependencies, providing a significant performance boost.
HELM_DEPS_SKIP_START_LOGIN	false	Skips login to all available registries at the start if combined with HELM_DEPS_SKIP_REFRESH=true.
HELM_DEPS_FETCH_ARGOCD_REPO_SECRETS	false	Adds registries that are registered in the argocd repository secrets.
HELM_DEPS_RANDOM_CACHE_DIR	false	Uses a random cache directory for the helm plugin. Useful for parallel executions when using in ArgoCD. This give additional speed boost of ~30%

Local

Local Usage:

export HELM_DEPS_SKIP_REPO_OVERWRITE=true
cd charts/benchmark-subchart-level-1
k8s-helm-dep-updater

# for maximum performance
export HELM_DEPS_SKIP_REFRESH=true
export HELM_DEPS_SKIP_REPO_OVERWRITE=true
export HELM_DEPS_SKIP_START_LOGIN=true
k8s-helm-dep-updater

Helm Plugin Usage

Usage as helm plugin is the same. All Configuration needs to be done via environment variables.

export HELM_DEPS_SKIP_REPO_OVERWRITE=true
helm template . -f deps://dummy

Changelog V2

Here are the major changes for version 2:

Improved Runtime The runtime has been reduce significantly by 50-80% depending on how many chart depedencies need to be installed. This was achieved by using go routines to install the dependencies in parallel, that are on the same hierarchy level.

This benchmark was done on a chart with 3 hierarchy levels and around 40 dependencies in total.

helm template . -f deps://dummy -f env/qa/values.yaml  181.52s user 12.70s system 152% cpu 2:07.40 total # V1

export HELM_DEPS_SKIP_REPO_OVERWRITE=true
helm template . -f deps://dummy -f env/qa/values.yaml  200.83s user 19.00s system 358% cpu 1:01.37 total # V2 Default

export HELM_DEPS_SKIP_REFRESH=true
export HELM_DEPS_SKIP_REPO_OVERWRITE=true
export HELM_DEPS_SKIP_START_LOGIN=true
helm template . -f deps://dummy -f env/qa/values.yaml  129.04s user 8.81s system 286% cpu 48.064 total # V2 Performance

export HELM_DEPS_RANDOM_CACHE_DIR=true
helm template -f env/qa/values.yaml -f deps://dummy . > app.yaml  41.07s user 6.11s system 184% cpu 25.541 total # V2 Performance with Random Cache Dir