Helm

helm.md

Helm

Kubernetes package manager for managing a lot of yaml files

basic flow

[ *bundle of yamls* -> chart ]  <──────────────────────── management tool "helm"
                          └─> "tgz" file is created.         
                                  └─> upload "Chart repository"  | monocular:Web UI for Helm Chart
                                                                 | chartmuseum: Chart for S3,GCS and so on(Cloud storage)
                       
[ helm client (cli tool) ] ──(grpc)──> helm Tiller Server ──(kubernetes api call)──> install chart on kubernetes clusters

• but Helm3, tiller is gone. https://github.com/helm/community/blob/master/helm-v3/000-helm-v3.md
• chart(configurations for k8s application), config(config map for injection), release(executed instances w/specific config)

how to install

1. helm client : brew install kubernetes-helm
2. helm tiller server

• before you installed, kubeconfig should be setup.
• helm init

command of helm

• helm repo update
• helm repo list
• helm install stable/redis
• helm ls
• helm del erstwhile-quail

directory design of helm

you can create a chart with the basic structure using helm create command

wordpress/
 └─Chart.yaml          # information of Chart
 └─LICENSE
 └─README.md      
 └─requirements.yaml   # dependency of Chart
 └─vaules.yaml         # default value of Chart
 └─charts/             # related chart with this Chart
 └─templates/          # yaml files for kubernetes manifest
 └─templates/NOTES.txt # short manual

how to customizaion the Chart

helm fetch stable/redis

$ tar zxvf redis-4.3.0.tgz
x redis/Chart.yaml
x redis/values.yaml
x redis/templates/NOTES.txt
x redis/templates/_helpers.tpl
x redis/templates/configmap.yaml
x redis/templates/health-configmap.yaml
x redis/templates/metrics-deployment.yaml
x redis/templates/metrics-prometheus.yaml
x redis/templates/metrics-svc.yaml
x redis/templates/networkpolicy.yaml
x redis/templates/redis-master-statefulset.yaml
x redis/templates/redis-master-svc.yaml
x redis/templates/redis-role.yaml
x redis/templates/redis-rolebinding.yaml
x redis/templates/redis-serviceaccount.yaml
x redis/templates/redis-slave-deployment.yaml
x redis/templates/redis-slave-svc.yaml
x redis/templates/secret.yaml
x redis/.helmignore
x redis/README.md
x redis/values-production.yaml

helm install ./redis