Cheatsheet collection

• Home
• Ansible
• Git
• GCP
• Docker
• Azure
• Terraform
• Helm
• ElasticSearch
• Kubernetes
• Istio
• OIDC
• PostgreSQL
• Terraform

---

“The package manager for k8s, provide users with a better way to manage all the Kubernetes YAML files for a k8s project”

• managing multiple k8s objects it’s hard (versioning yaml 😔) - helm allows yml templating

• Helm chart contents:

• helm repos: https://artifacthub.io/ and https://bitnami.com/ (VMWare)
• Kustomize (patch k8s obj) kubectl kustomize . vs HELM (package manager)
• HELM2 (using Tiller pod inside k8s) vs HELM3 which communicates directly with K8s API server (ditch Tiller approach)

## REPOSITORY = chart repository is a location where packaged charts can be stored and share
## CHART = bundle/collection of one or more Kubernetes manifests, a chart is a Helm pacakge.
## RELEASE = instance of a chart running in a k8s cluster.

# add chart repo <REPO_NAME> has been added to your repositories
# downloads an index file that lists all the available charts in the repository
helm repo add [REPO_NAME] [URL]
helm repo add bitnami https://charts.bitnami.com/bitnami

# Make sure we get the latest list of charts
helm repo update 

# list repos
helm repo list
# list charts
helm list -A

# add/list/update repositories: 
helm repo add [REPO_NAME] [URL]
helm repo list
# Make sure we get the latest list of charts
helm repo update
helm search repo <CHART> --versions

# Retrieve a package from a package repository, and download it locally to a tgz file
# Download a chart from a repository and (optionally) unpack it in local directory
helm pull [chart URL | repo/chartname]

# nice flow add repo -> fetch chart to inspect
helm repo add cetic https://cetic.github.io/helm-charts
# download and extract the chart
helm fetch cetic/pgadmin --untar

# install chart very usefull --dry-run
helm install [NAME] [CHART] [flags]

# install latest chart version
helm upgrade -i <release_name> <REPO_NAME>  /<CHART> --version 2.12

# override values
helm install --set replicaCount=2  <release_name> <CHART>

# create chart
helm create <chart name>

# pick the latest chart and update him : Release "<RELEASE_NAME>  " does not exist. Installing it now.
helm upgrade -i <RELEASE_NAME>  <REPO>/<CHART> --version 2.16

# Install chart:
helm install bitnami/mysql --generate-name
helm install <realease_name> bitnami/rabbitmq

• When installing Helm, make sure you’re installing version 3. Version 2 still works, but it needs a server-side component called Tiller, which ties your helm installation to a single cluster. Helm 3 removed this need with the addition of several CRDs, but it’s not supported in all Kubernetes versions.

• Helm chart repositories Artifact Hub:

• RabbitMQ flow:

helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update
helm repo list
helm search repo bitnami
helm fetch bitnami/rabbitmq --untar

# create k8s namespace
kubectl create ns rabbit

# helm install <release_name> bitnami/rabbitmq
helm install testrabbit ./rabbitmq/ --namespace rabbit

# auto generate name 
helm install bitnami/rabbitmq --generate-name --namespace rabbit

# list charts and view charts history
helm list

# delete/uninstall chart
helm delete <release_name>

# get helmrealease for a namespace
kubectl -n <namespace> get hr

# get helm values for a chart
helm -n <namespace> get values <chart_name>

---

                    ___ _____
                   /\ (_)    \
                  /  \      (_,
                 _)  _\   _    \
                /   (_)\_( )____\
                \_     /    _  _/
                  ) /\/  _ (o)(
                  \ \_) (o)   /
                   \/________/         @dejanualex