# Useful commands for Helm > Helm is an open source package manager for Kubernetes. It provides the ability to provide, share, and use software built for Kubernetes. In this post, we will cover the most common Helm commands (and their most common parameters) from our daily work and provide a brief review of the core concepts. You can review the official documentation [here](https://helm.sh/docs/). # Helm core concepts * The **Chart** is a Helm package that contains information sufficient for installing a set of Kubernetes resources into a Kubernetes cluster. * The **Repository** is a simple HTTP server to store collection of charts. You can search, download and install charts from a repository. * The **Release** is an instance or a deployment of a chart. When you perform a helm install command, you are creating a new release of that chart on your Kubernetes cluster. # Helm commands ## Repository management List chart repositories: ```powershell helm repo list ``` ```powershell helm repo list NAME URL bitnami https://charts.bitnami.com/bitnami ingress-nginx https://kubernetes.github.io/ingress-nginx ``` Search for charts in the local repositories: ```powershell helm search repo [keyword] ``` ```powershell helm search repo rabbitmq NAME CHART VERSION APP VERSION DESCRIPTION bitnami/rabbitmq 9.0.0 3.9.16 RabbitMQ is an open source general-purpose mess... bitnami/rabbitmq-cluster-operator 2.6.0 1.12.1 The RabbitMQ Cluster Kubernetes Operator automa... ``` Search for charts in the [Artifact Hub](https://artifacthub.io/): ```powershell helm search hub [keyword] -o yaml ``` ```powershell helm search hub jaeger -o yaml - app_version: 1.17.1 description: A Jaeger Helm chart for Kubernetes repository: name: hkube url: https://hkube.io/helm/ url: https://artifacthub.io/packages/helm/hkube/jaeger version: 0.27.2006 - app_version: 1.30.0 description: A Jaeger Helm chart for Kubernetes repository: name: jaegertracing url: https://jaegertracing.github.io/helm-charts url: https://artifacthub.io/packages/helm/jaegertracing/jaeger version: 0.56.1 ``` Add a repository: ```powershell helm repo add [repository] [repository-url] ``` ```powershell helm repo add jaegertracing https://jaegertracing.github.io/helm-charts "jaegertracing" has been added to your repositories ``` Update information of charts in local repositories: ```powershell helm repo update ``` ```powershell helm repo update Hang tight while we grab the latest from your chart repositories... ...Successfully got an update from the "ingress-nginx" chart repository ...Successfully got an update from the "jaegertracing" chart repository ``` ## Chart management ### Using packages created by us Create a directory containing the common chart files and directories: ```powershell helm create [chart] ``` ```csharp helm create demo-app Creating demo-app ``` Examine a chart for possible issues: ```powershell helm lint [chart] ``` ```powershell helm lint demo-app ==> Linting demo-app [INFO] Chart.yaml: icon is recommended ``` Upgrade a release: ```powershell helm upgrade [release] [chart] ``` ```powershell --namespace namespace scope for this request --install if a release by this name doesn't already exist, run an install --dry-run simulate an upgrade --debug enable verbose output --values specify values in a YAML file or a URL (can specify multiple) --set set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2) --create-namespace if --install is set, create the release namespace if not present ``` ```powershell helm upgrade release-demo demo-app --debug --install --values values.local.yaml --set image.tag=1.0.0 ``` Package a chart directory into a chart archive: ```powershell helm package [chart] --app-version ``` ```powershell helm package demo-app --app-version 1.0.0 Successfully packaged chart and saved it to: C:\demo-app-1.0.0.tgz ``` Push a chart to a remote repository (depending on the server): * [Azure Container Registry](https://docs.microsoft.com/en-us/azure/container-registry/container-registry-helm-repos) * [Amazon ECR](https://docs.aws.amazon.com/AmazonECR/latest/userguide/push-oci-artifact.html) ### Using packages from a remote repository Show the chart's definition: ```powershell helm show chart [chart] ``` ```powershell helm show chart ingress-nginx/ingress-nginx apiVersion: v2 appVersion: 1.2.0 description: Ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer home: https://github.com/kubernetes/ingress-nginx icon: https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Nginx_logo.svg/500px-Nginx_logo.svg.png keywords: - ingress - nginx kubeVersion: '>=1.19.0-0' maintainers: - name: rikatz - name: strongjz - name: tao12345666333 name: ingress-nginx sources: - https://github.com/kubernetes/ingress-nginx type: application version: 4.1.0 ``` Show the chart's values: ```powershell helm show values [chart] ``` Download a chart from a repository: ```powershell helm pull [chart] ``` ```powershell helm pull ingress-nginx/ingress-nginx ``` Install a chart: ```powershell helm install [release] [chart] ``` ```csharp helm install ingress-nginx/ingress-nginx ``` ## Release management List releases: ```powershell helm list --namespace [namespace] ``` ```powershell helm list --namespace default NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION release-demo default 3 2022-04-27 14:09:35.2202953 -0500 -05 failed demo-app-1.0.0 1.16.0 ``` Fetch release history: ```powershell helm history [release] ``` ```powershell helm history release-demo REVISION UPDATED STATUS CHART APP VERSION DESCRIPTION 1 Wed Apr 27 08:52:02 2022 superseded demo-app-0.1.0 1.16.0 Upgrade complete 2 Wed Apr 27 12:53:03 2022 deployed demo-app-0.1.0 1.16.0 Upgrade complete 3 Wed Apr 27 14:09:35 2022 failed demo-app-1.0.0 1.16.0 Upgrade "demo-app" failed: pre-upgrade hooks failed: timed out waiting for the condition ``` Rollback a release to a previous revision: ```powershell helm rollback [release] [revision] ``` ```powershell helm rollback demo-app 2 Rollback was a success! Happy Helming! ``` Uninstall a release: ```powershell helm uninstall [release] ``` ```powershell helm uninstall demo-app release "demo-app" uninstalled ```