helm-wrapper

helm-wrapper is a tool that wraps Kubernetes Helm to simplify helm/tiller version management.

⚠️ Helm v2 is no longer supported. This repository is now archived.

Why do I need helm-wrapper?

When using helm, have you ever seen this message, or something similar?

Error: incompatible versions client[v2.9.1] server[v2.8.2]

Given that:

• Helm has two parts: a client (helm) and a server (tiller)
• In many cases the client and the server versions must match for a helm call to succeed.
• A common Helm security best practice is installing a tiller server in each Kubernetes namespace that helm will be used.
• Many organizations use multiple clusters.

Keeping the same tiller version across all clusters and all namespaces at all times is impractical. This forces users and build scripts to use several different helm client versions - a problem that is frustrating and error-prone.

helm-wapper solve this problem by negotiating with the target tiller, determining its version, and then using the corresponding helm client for each request. It does this automatically so the user/script does not need to be modified from its current helm usage.

Tiller Namespace

For helm commands that call the server, helm-wrapper must first calculate the tiller namespace so that it can determine the installed tiller version. It uses the following algorithm to determine the tiller namespace:

1. use --tiller-namespace if specified in command
2. use TILLER_NAMESPACE environment variable if it is set
3. use the current kubectl config ("kubeconfig") namespace if it is set ← this is divergent behavior from helm, but simplifies working in a tiller-per-namespace environment
4. use the default helm namespace, kube-system

Installation

  HELM_WRAPPER_VERSION=v1.0.0

  # remove old helm if it exists
  sudo rm -rf /usr/local/bin/helm

  # install helm wrapper
  curl https://raw.githubusercontent.com/cradlepoint/helm-wrapper/${HELM_WRAPPER_VERSION}/helm -o helm
  chmod +x ./helm
  sudo mv ./helm /usr/local/bin/helm

  # download helm installer
  curl https://raw.githubusercontent.com/cradlepoint/helm-wrapper/${HELM_WRAPPER_VERSION}/install-helm-versions.sh -o install-helm-versions.sh
  chmod +x ./install-helm-versions.sh

  # use installer to install desired helm versions (https://github.com/helm/helm/releases)
  # usage: ./install-helm-versions.sh [ver1 ver2 verN]
  ./install-helm-versions.sh 2.12.3 2.13.1