Installing latest Helm version hits API rate limit after 60 executions

[lukerogers]

We use a hosted agent for Helm deployments to speed up the process and if we are deploying a lot of services we hit the rate limit when the task is trying to get the latest stable version.

Downloading: https://api.github.com/repos/helm/helm/releases
##[warning]Cannot get the latest Helm info from https://api.github.com/repos/helm/helm/releases. Error Error: Unexpected HTTP response: 403

In the code located at common-npm-packages/kubernetes-common/helmutility.ts it is loading the full list of releases on each run if a version is not specified, meaning get the latest version. If that request is rate limited and returns a 403 it will fall back to the old version 3.1.2 from March 2020 which is missing functionality and breaks pipelines.

This issue was reported in microsoft/azure-pipelines-tasks#17569 with the "fix" to install it on the machine and skip the helm installer. This is inflexible and requires regular updates.

I think at the least a more recent version number should be the fallback. The use of the newer https://get.helm.sh/helm-latest-version endpoint to get the latest version could work too since it's hitting a storage account, but I don't know if they post RC versions there or not.

I am using the following workaround to hopefully prevent rate limit issues:

- bash: |
    url="https://get.helm.sh/helm-latest-version"
    version=$(curl -s $url | sed 's/^v//')
    echo "Latest Helm Version: $version"
    echo "##vso[task.setvariable variable=HELM_VERSION]$version"
  displayName: 'Get latest version of Helm'

- task: HelmInstaller@1
  displayName: 'Install Helm'
  inputs: 
    helmVersionToInstall: $(HELM_VERSION)