Sivakumar Vunnam

Helm

Oct 1, 2022 • Sivakumar Vunnam

This cheat sheet is organized as per the typical workflow for Helm3

1) Add a chart repository.
2) Find a chart to install.
3) Install a Helm chart.
4) See the list of what is installed.
5) Upgrade your installation.
6) Delete the installation.

Add, remove, list, search and Update Repos

    helm repo add [name] [url] #Add a repository from the internet
    helm repo remove [name] #Remove a repository from your system
    helm repo update #Update repositories
    helm repo list #List chart repositories
    helm repo index #Generate an index file containing charts found in the current directory
    helm search [keyword] #Search charts for a keyword
    helm search repo [keyword] #Search repositories for a keyword
    helm search hub [keyword] #Search Helm Hub

List available packages

To list charts (packages)

    helm search hub wordpress #helm search hub searches the Artifact Hub
    helm search repo wordpress #helm search repo searches the repositories that you have added to your local helm client (with helm repo add)

Install and Uninstall Apps

    helm install [name] [chart] --namespace [namespace] #Install an app in a specific namespace
    helm install [name] [chart] --values [yaml-file/url] #Override the default values with those specified in a file of your choice
    helm install [name] --dry-run --debug #Run a test install to validate and verify the chart
    helm uninstall [release name]  #Uninstall a release

Chart Management

    helm create [name] #Create a directory containing (Chart.yaml, values.yaml,charts/ and templates/)
    helm package [chart-path] #Package a chart into a chart archive
    helm lint [chart] #Run tests to examine a chart and identify possible issues
    helm show all [chart] #Inspect a chart and list its contents
    helm show chart [chart] #Display the chart’s definition
    helm show values [chart] #Display the chart's values
    helm pull [chart] #Download a chart
    helm pull [chart] --untar --untardir [directory] #Download a chart and extract the archive’s contents into a directory
    helm dependency list [chart] #Display a list of a chart’s dependencies
    helm install mychart-0.1.0.tgz --dry-run --debug #Test installation

Helm Plugin Management

    helm plugin list #view a list of all the installed plugins 
    helm plugin install <plugin URL> #Install Plugins
    helm plugin update [plugin1] [plugin2] #update plugin
    helm plugin uninstall [plugin1] #Uninstall a plugin

Setup Docker Registry as Helm Chart Repo

    export HELM_EXPERIMENTAL_OCI=1

Upgrading ,Rollback and list releases

    helm upgrade [release] [chart] #Upgrade an app
    helm upgrade [release] [chart] --atomic #Tell Helm to roll back changes if the upgrade fails
    helm upgrade [release] [chart] --install #Upgrade a release. If it does not exist on the system, install it
    helm upgrade [release] [chart] --version [version-number] #Upgrade to a version other than the latest one
    helm rollback [release] [revision] #Roll back a release
    helm upgrade --wait <name> # Wait for pods to come up
    helm ls #List releases in current namespace
    helm ls -A #List all releases in all namespaces
    helm ls -A -o json | jq  -r '.[] | select(.status = "deployed") | .name' #Find releases in unexpected state
    helm get values <release> # Print the values the release was installed with

Download Release Information

    helm get all [release] #Download all the release information
    helm get hooks [release] #Download all hooks
    helm get manifest [release] #Download the manifest
    helm get notes [release] #Download the notes
    helm get values [release] #Download the values file
    helm history [release] #Fetch release history

##Get help and Version Info

    helm --help #See the general help for Helm
    helm [command] #help #See help for a particular command
    helm version #See the installed version of Helm

##Release Monitoring

    helm list #List all the available releases in the current namespace
    helm list --all-namespaces #List all the available releases across all namespaces
    helm list --namespace [namespace] #List all the releases in a specific namespace
    helm list --output [format] #List all the releases in a specific output format
    helm list --filter ‘[expression]’ #Apply a filter to the list of releases using regular (Pearl compatible) expressions
    helm status [release] #See the status of a release
    helm history [release] #See the release history
    helm env #See information about the Helm client environment

Using Helm in Terraform

Dependency in main.tf

terraform {
  required_providers {
    helm = {
      version = ">= 3.5"
    }
  }
}

Declaring Helm ressources with terraform

 resource "helm_release" "myreleasename" {
   name = "myreleasename"
   namespace = "<namespace>"
   create_namespace = <true|false>
   chart = "<path to local chart|chart name>"
 }

Best Practices

See https://helm.sh/docs/chart_best_practices/conventions/