Top 10 Essential Helm Commands for Site Reliability Engineers

Top ten Helm commands for Site Reliability Engineers.

1. helm install: Installs a chart in a Kubernetes cluster.

Example: Install the stable/nginx-ingress chart with the release name nginx-ingress:

$ helm install nginx-ingress stable/nginx-ingress

Output:

NAME: nginx-ingress
LAST DEPLOYED: Thu Aug 19 10:31:17 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
The NGINX Ingress Controller has been installed.

2. helm upgrade: Upgrades a release to a new version.

Example: Upgrade the nginx-ingress release to the latest version:

$ helm upgrade nginx-ingress stable/nginx-ingress

Output:

Release "nginx-ingress" has been upgraded. Happy Helming!
LAST DEPLOYED: Thu Aug 19 10:33:50 2021
NAMESPACE: default
STATUS: deployed
REVISION: 2
TEST SUITE: None

3. helm rollback: Rolls back a release to a previous version.

Example: Roll back the nginx-ingress release to the previous version:

$ helm rollback nginx-ingress 1

Output:

Rollback was a success! Happy Helming!

4. helm list: Lists all releases in a Kubernetes cluster.

Example: List all releases in the Kubernetes cluster:

$ helm list

Output:

NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
nginx-ingress   default         2               2021-08-19 10:33:50.668202851 -0400 EDT  deployed        nginx-ingress-1.41.3    1.19.0

5. helm delete: Deletes a release from a Kubernetes cluster.

Example: Delete the nginx-ingress release:

$ helm delete nginx-ingress

Output:

release "nginx-ingress" uninstalled

6. helm package: Packages a chart into a versioned archive.

Example: Package the nginx-ingress chart into a versioned archive:

$ helm package stable/nginx-ingress

Output:

Successfully packaged chart and saved it to: /home/user/nginx-ingress-1.41.3.tgz

7. helm repo add: Adds a chart repository to Helm.

Example: Add the stable repository to Helm:

$ helm repo add stable https://charts.helm.sh/stable

Output:

"stable" has been added to your repositories

8. helm repo update: Updates the local cache of a chart repository.

Example: Update the local cache of the stable repository:

$ helm repo update

Output:

Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈Happy Helming!⎈

9. helm lint: Lints a chart for errors.

Example: Lint the nginx-ingress chart:

$ helm lint stable/nginx-ingress

Output:

==> Linting stable/nginx-ingress
[INFO] Chart.yaml: icon is recommended
1 chart(s) linted, no failures

10. helm template: Renders a chart as Kubernetes manifests.

Example: Render the nginx-ingress chart as Kubernetes manifests:

$ helm template nginx-ingress stable/nginx-ingress > nginx-ingress.yaml

Output: This command will generate a YAML file containing the Kubernetes manifests for the nginx-ingress release. The output will be saved to a file named nginx-ingress.yaml. You can then use this file to apply the manifests to a Kubernetes cluster using kubectl apply -f. Note that this command does not install the chart in the cluster, but only renders the manifests.