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helm Cheatsheet

Releases​

List Releases in All Namespaces​

helm list --all-namespaces

Upgrading Release​

helm upgrade --install app-gw app/app-api-gateway -f deploy/akl-gw/values.yaml

Get Release Values​

Helm saves the deployment values in a secret in the namespace where the chart was deployed. We can retrieve them in JSON format using:

kubectl get secret sh.helm.release.v1.$release_name.$release_version \
-o jsonpath='{.data.release}' \
| base64 -d \
| base64 -d \
| gunzip \
| jq > $release_name.$release_version.json

Repo​

Adding Repo​

helm repo add app https://applabs.github.io/helm-charts
helm repo update

Updating Repo​

helm repo app update

Updating Repo with Git Change​

If we want to update a repo to use a specific git ref (e.g. branch, commit), we can use helm git. For example, if we pushed a change to a chart in a remote branch (fix-allowedAccessPermissions-type-api-gw) and we want to test it out, we can add a new helm repo:

helm repo add app-dev git+https://github.com/applabs/helm-charts@charts?ref=fix-allowedAccessPermissions-type-api-gw

Charts​

Checking Chart Versions​

helm search repo $MY_REPO/$MY_CHART --versions

Upgrading Chart to Specific Version​

helm upgrade $MY_RELEASE_NAME $MY_REPO/$MY_CHART -f $MY_CHART_VALUES.yaml --version $NEW_CHART_VERSION

Get Chart Values​

helm show values app/app-api-gateway | yq

Overriding Values​

Helm charts use customizable values.yaml files that allow you to override default configurations using --set flags.

helm install my-postgres bitnami/postgresql \
  --set global.postgresql.auth.postgresPassword=yourpassword \
  --set global.postgresql.auth.username=myuser \
  --set global.postgresql.auth.password=mypassword \
  --set global.postgresql.auth.database=mydatabase

Generating Post-Processed YAML Manifests​

In some situations we will want to generate the post-processed YAML file(s) manifests that include all the Kubernetes resources that helm uses to later kubectl apply them to the cluster.

To render the manifest into one file, we can use:

helm template \
$RELEASE_NAME \
$CHART_PATH_OR_NAME \
--namespace $NAMESPACE \
-f values.yaml > $OUTPUT_FILENAME.yaml

# example for postgres
helm template \
mypostgres \
bitnami/postgresql \
--namespace database > postgresql.yaml

To render separate manifests into a directory instead of one file:

helm template \
$RELEASE_NAME \
$CHART_PATH_OR_NAME \
--namespace $NAMESPACE \
--output-dir ./generated-manifests \
-f values.yaml
helm template \
mypostgres \
bitnami/postgresql \
--namespace database \
--output-dir ./generated-manifests \
-f values.yaml

Pulling Chart​

helm pull bitnami/redis --version 1.48.2 --untar --untardir /tmp/redis