add post / helm hands on

KimDoKy · Jan 17, 2024 · c444c1d · c444c1d
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diff --git a/_posts/devops/2024-01-16-devops-helm-handson.md b/_posts/devops/2024-01-16-devops-helm-handson.md
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+---
+layout: post
+section-type: post
+title: Helm Hands On
+category: devops
+tags: [ 'k8s', 'helm' ]
+---
+
+## Install Helm CLI
+```bash
+# for Mac
+$ brew install helm
+
+# other linux
+$ curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3
+$ chmod 700 get_helm.sh     (== chmod +x get_helm.sh)
+$ ./get_helm.sh
+
+$ helm version
+```
+## Install Helm Chart
+```bash
+# add repo
+$ helm repo add bitnami https://charts.bitnami.com/bitnami
+"bitnami" has been added to your repositories
+$ helm repo list
+NAME    URL
+bitnami https://charts.bitnami.com/bitnami
+
+## remove repo
+$ helm repo remove [repo-name]
+
+# search repo
+$ helm search repo bitnami
+...
+
+# helm install [name] [chart] [flags]
+$ helm install my-release bitnami/wordpress
+NAME: my-release
+LAST DEPLOYED: Tue Jan 16 22:11:03 2024
+NAMESPACE: default
+STATUS: deployed
+REVISION: 1
+TEST SUITE: None
+NOTES:
+CHART NAME: wordpress
+CHART VERSION: 19.1.0
+APP VERSION: 6.4.2
+
+** Please be patient while the chart is being deployed **
+...
+
+# helm 조회
+$ helm ls
+NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART             APP VERSION
+my-release      default         1               2024-01-16 22:11:03.908208464 +0900 KST deployed        wordpress-19.1.0  6.4.2
+
+$ kubectl get po
+NAME                                     READY   STATUS    RESTARTS   AGE
+my-release-mariadb-0                     0/1     Pending   0          8m35s
+my-release-wordpress-bd87c998b-p7lz9     0/1     Pending   0          8m36s
+
+$ kubectl get cm
+NAME                 DATA   AGE
+kube-root-ca.crt     1      22d
+my-release-mariadb   1      9m46s
+
+$ kubectl get svc
+NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
+kubernetes             ClusterIP      10.96.0.1       <none>        443/TCP                      22d
+my-release-mariadb     ClusterIP      10.104.108.96   <none>        3306/TCP                     10m
+my-release-wordpress   LoadBalancer   10.104.88.7     <pending>     80:31380/TCP,443:31234/TCP   10m
+
+$ kubectl get pvc
+NAME                        STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
+data-my-release-mariadb-0   Pending                                                     10m
+my-release-wordpress        Pending                                                     10m
+
+$ kubectl get secret
+NAME                               TYPE                 DATA   AGE
+my-release-mariadb                 Opaque               2      11m
+my-release-wordpress               Opaque               1      11m
+sh.helm.release.v1.my-release.v1   helm.sh/release.v1   1      11m
+
+## minikube로 실행시 tunnel을 통해 external ip를 생성할 수 있다.
+$ minikube tunnel
+$ kubectl get svc
+```
+## Upgrade Helm Chart
+```bash
+# helm upgrade [release] [chart] [flags]
+# ex) helm upgrade -f myvalues.yaml -f override.yaml redis ./redis
+# ex) helm upgrade --set foo=bar --set foo=newbar redis ./redis
+$ cat myvalues.yaml
+replicaCount: 3
+
+$ helm ls
+NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART             APP VERSION
+my-release      default         1               2024-01-16 22:11:03.908208464 +0900 KST deployed        wordpress-19.1.0  6.4.2
+
+$ helm upgrade my-release bitnami/wordpress -f myvalues.yaml
+Release "my-release" has been upgraded. Happy Helming!
+NAME: my-release
+LAST DEPLOYED: Tue Jan 16 22:39:49 2024
+NAMESPACE: default
+STATUS: deployed
+REVISION: 2
+TEST SUITE: None
+NOTES:
+CHART NAME: wordpress
+CHART VERSION: 19.1.0
+APP VERSION: 6.4.2
+
+** Please be patient while the chart is being deployed **
+...
+
+$ kubectl get po
+NAME                                     READY   STATUS    RESTARTS   AGE
+my-release-mariadb-0                     0/1     Pending   0          29m
+my-release-wordpress-bd87c998b-6hmbf     0/1     Pending   0          22s
+my-release-wordpress-bd87c998b-mj9gc     0/1     Pending   0          22s
+my-release-wordpress-bd87c998b-p7lz9     0/1     Pending   0          29m
+
+$ helm ls
+NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART             APP VERSION
+my-release      default         2               2024-01-16 22:39:49.207040692 +0900 KST deployed        wordpress-19.1.0  6.4.2
+
+$ kubectl get deploy
+NAME                     READY   UP-TO-DATE   AVAILABLE   AGE
+my-release-wordpress     0/3     3            0           31m
+
+## revision을 secret으로 따로 관리한다.
+## rollback시 이를 사용하여 복구한다.
+$ kubectl get secret
+NAME                               TYPE                 DATA   AGE
+my-release-mariadb                 Opaque               2      32m
+my-release-wordpress               Opaque               1      32m
+sh.helm.release.v1.my-release.v1   helm.sh/release.v1   1      32m
+sh.helm.release.v1.my-release.v2   helm.sh/release.v1   1      3m37s
+
+# release가 가지고 있는 값 조회
+# helm get [command]
+## command: all, hooks, manifest, notes, values
+$ helm get values my-release
+USER-SUPPLIED VALUES:    # user가 추가한 값. 기본과 다르다는 것을 알 수 있음
+replicaCount: 3
+
+## revision을 명시하여 바뀐 점을 알 수 있다.
+$ helm get values my-release --revision 1
+USER-SUPPLIED VALUES:
+null
+
+# revision의 다른 점을 조회하는 diff 플러그인이 있다.
+## diff 플러그인 설치
+$ helm plugin install https://github.com/databus23/helm-diff
+# helm diff [command]
+## command: release, revision, rollback, upgrade, version
+$ helm diff revision my-release 1 2
+default, my-release-wordpress, Deployment (apps) has changed:
+...
+    strategy:
+      type: RollingUpdate
+-   replicas: 1
++   replicas: 3
+    template:
+...
+```
+## RollBack Helm Chart
+```bash
+$ helm ls
+NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART             APP VERSION
+my-release      default         2               2024-01-16 22:39:49.207040692 +0900 KST deployed        wordpress-19.1.0  6.4.2
+
+$ cat myvalues.yaml
+replicaCount: 3
+
+# helm history
+$ helm history my-release
+REVISION        UPDATED                         STATUS          CHART                   APP VERSION     DESCRIPTION
+1               Tue Jan 16 22:11:03 2024        superseded      wordpress-19.1.0        6.4.2           Install complete
+2               Tue Jan 16 22:39:49 2024        deployed        wordpress-19.1.0        6.4.2           Upgrade complete
+
+# helm rollback <release> [revision]
+## --dry-run : 실제로 수행하지 않고 수행되었을 때의 결과만 알려준다.
+$ helm rollback my-release 1 --dry-run
+Rollback was a success! Happy Helming!
+$ helm rollback my-release 1
+Rollback was a success! Happy Helming!
+$ helm history my-release
+REVISION        UPDATED                         STATUS          CHART                   APP VERSION     DESCRIPTION
+1               Tue Jan 16 22:11:03 2024        superseded      wordpress-19.1.0        6.4.2           Install complete
+2               Tue Jan 16 22:39:49 2024        superseded      wordpress-19.1.0        6.4.2           Upgrade complete
+3               Wed Jan 17 08:12:24 2024        deployed        wordpress-19.1.0        6.4.2           Rollback to 1
+## revision 1과 같은 상태인 것을 알 수 있다.
+$ helm get values my-release --revision 3
+USER-SUPPLIED VALUES:
+null
+$ kubectl get deploy
+NAME                     READY   UP-TO-DATE   AVAILABLE   AGE
+my-release-wordpress     0/1     1            0           10h
+nfs-client-provisioner   1/1     1            1           17d
+$ kubectl get po
+NAME                                     READY   STATUS    RESTARTS   AGE
+my-release-mariadb-0                     0/1     Pending   0          10h
+my-release-wordpress-bd87c998b-p7lz9     0/1     Pending   0          10h
+```
+## Delete Helm Chart
+```bash
+# helm uninstall
+## alias: uninstall, del, delete, un
+## --key-history : 자원을 모두 지우지만, 지우는 것도 revision으로 관리하여 복구할 수 있다.(secret 유지)
+$  helm delete my-release --keep-history
+release "my-release" uninstalled
+# 관련 자원들이 모두 삭제되었다.
+$ helm ls
+NAME    NAMESPACE       REVISION        UPDATED STATUS  CHART   APP VERSION
+$ kubectl get po
+No resources found in default namespace.
+$ kubectl get svc
+NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
+kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   22d
+$ kubectl get cm
+NAME               DATA   AGE
+kube-root-ca.crt   1      22d
+
+# history를 조회하면 revision이 secret을 통해 관리되고 있다.
+$  helm history my-release
+REVISION        UPDATED                         STATUS          CHART                   APP VERSION     DESCRIPTION
+1               Tue Jan 16 22:11:03 2024        superseded      wordpress-19.1.0        6.4.2           Install complete
+2               Tue Jan 16 22:39:49 2024        superseded      wordpress-19.1.0        6.4.2           Upgrade complete
+3               Wed Jan 17 08:12:24 2024        superseded      wordpress-19.1.0        6.4.2           Rollback to 1
+4               Wed Jan 17 08:19:16 2024        uninstalled     wordpress-19.1.0        6.4.2           Uninstallation complete
+$ kubectl get secret
+NAME                               TYPE                 DATA   AGE
+sh.helm.release.v1.my-release.v1   helm.sh/release.v1   1      10h
+sh.helm.release.v1.my-release.v2   helm.sh/release.v1   1      9h
+sh.helm.release.v1.my-release.v3   helm.sh/release.v1   1      14m
+sh.helm.release.v1.my-release.v4   helm.sh/release.v1   1      7m23s
+
+## 다시 rollback
+$ helm history my-release
+REVISION        UPDATED                         STATUS          CHART                   APP VERSION     DESCRIPTION
+1               Tue Jan 16 22:11:03 2024        superseded      wordpress-19.1.0        6.4.2           Install complete
+2               Tue Jan 16 22:39:49 2024        superseded      wordpress-19.1.0        6.4.2           Upgrade complete
+3               Wed Jan 17 08:12:24 2024        superseded      wordpress-19.1.0        6.4.2           Rollback to 1
+4               Wed Jan 17 08:19:16 2024        uninstalled     wordpress-19.1.0        6.4.2           Uninstallation complete
+5               Wed Jan 17 08:29:18 2024        deployed        wordpress-19.1.0        6.4.2           Rollback to 4
+$ kubectl get po
+NAME                                     READY   STATUS    RESTARTS   AGE
+my-release-mariadb-0                     0/1     Pending   0          23s
+my-release-wordpress-bd87c998b-5lbqz     0/1     Pending   0          23s
+my-release-wordpress-bd87c998b-fmsbq     0/1     Pending   0          23s
+my-release-wordpress-bd87c998b-gj26p     0/1     Pending   0          23s
+
+## namespace를 지우면 해당 secret 및 revision도 삭제된다.
+# 완전 삭제
+## 복구 불가
+$ helm ls
+NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                   APP VERSION
+my-release      default         5               2024-01-17 08:29:18.617890062 +0900 KST deployed        wordpress-19.1.0        6.4.2
+$ helm delete my-release
+release "my-release" uninstalled
+$ helm ls
+NAME    NAMESPACE       REVISION        UPDATED STATUS  CHART   APP VERSION
+$ helm history my-release
+Error: release: not found
+$ kubectl get secret
+No resources found in default namespace.
+```