- 記事作成日：2022/11/30
情報
| 名前 | URL |
|---|---|
| Github | https://github.com/ahmetb/kubectl-foreach |
| 公式サイト | |
| デモサイト | |
| 開発母体 | ahmetb 氏 |
| version | 0.2.1 |
| 言語 | Go |
| 価格 | 無料 |
| ライセンス | Apache-2.0 license |
何ができるもの？
複数の Kubernetes クラスタにまとめて kubectl が実行できます。
使い方
go install github.com/ahmetb/kubectl-foreach@latest
kind でクラスタを作っておく
kind create cluster --name 1 kind create cluster --name 2 kind create cluster --name 3
version チェック
❯ kubectl foreach kind-1 kind-2 kind-3 -- version --short Will run command in context(s): - kind-1 - kind-2 - kind-3 Continue? [Y/n]: Y kind-3 | Flag --short has been deprecated, and will be removed in the future. The --short output will become the default. kind-2 | Flag --short has been deprecated, and will be removed in the future. The --short output will become the default. kind-1 | Flag --short has been deprecated, and will be removed in the future. The --short output will become the default. kind-1 | Client Version: v1.25.0 kind-1 | Kustomize Version: v4.5.7 kind-1 | Server Version: v1.25.3 kind-3 | Client Version: v1.25.0 kind-3 | Kustomize Version: v4.5.7 kind-3 | Server Version: v1.25.3 kind-2 | Client Version: v1.25.0 kind-2 | Kustomize Version: v4.5.7 kind-2 | Server Version: v1.25.3
3ついっぺんにみれている
正規表現
ホスト名を正規表現で引っ掛けることもできる。
❯ kubectl foreach "/^kind-[12]/" -- get pods -A Will run command in context(s): - kind-1 - kind-2 Continue? [Y/n]: kind-1 | NAMESPACE NAME READY STATUS RESTARTS AGE kind-1 | kube-system coredns-565d847f94-4tz8g 1/1 Running 0 3m3s kind-1 | kube-system coredns-565d847f94-blfkj 1/1 Running 0 3m3s kind-1 | kube-system etcd-1-control-plane 1/1 Running 0 3m17s kind-1 | kube-system kindnet-92c9l 1/1 Running 0 3m4s kind-1 | kube-system kube-apiserver-1-control-plane 1/1 Running 0 3m17s kind-1 | kube-system kube-controller-manager-1-control-plane 1/1 Running 0 3m16s kind-1 | kube-system kube-proxy-6vkkz 1/1 Running 0 3m4s kind-1 | kube-system kube-scheduler-1-control-plane 1/1 Running 0 3m18s kind-1 | local-path-storage local-path-provisioner-684f458cdd-gx5zb 1/1 Running 0 3m3s kind-2 | NAMESPACE NAME READY STATUS RESTARTS AGE kind-2 | kube-system coredns-565d847f94-ln8vk 1/1 Running 0 2m46s kind-2 | kube-system coredns-565d847f94-twtg8 1/1 Running 0 2m46s kind-2 | kube-system etcd-2-control-plane 1/1 Running 0 2m59s kind-2 | kube-system kindnet-7pzzr 1/1 Running 0 2m46s kind-2 | kube-system kube-apiserver-2-control-plane 1/1 Running 0 2m59s kind-2 | kube-system kube-controller-manager-2-control-plane 1/1 Running 0 3m kind-2 | kube-system kube-proxy-68xbn 1/1 Running 0 2m46s kind-2 | kube-system kube-scheduler-2-control-plane 1/1 Running 0 3m1s kind-2 | local-path-storage local-path-provisioner-684f458cdd-njptd 1/1 Running 0 2m46s
特定のクラスタ以外
これで kind-3 以外が対象になる。
kubectl foreach ^kind-3 -- get pods -A
Nginx を起動する
-q は確認を出さない
❯ kubectl foreach -q /kind/ -- create ns nginx Will run command in context(s): - kind-1 - kind-2 - kind-3 kind-1 | namespace/nginx created kind-3 | namespace/nginx created kind-2 | namespace/nginx created ❯ kubectl foreach -1 /kind/ -- create deployment nginx --image=nginx --namespace nginx Will run command in context(s): - kind-1 - kind-2 - kind-3 kind-3 | deployment.apps/nginx created kind-2 | deployment.apps/nginx created kind-1 | deployment.apps/nginx created ❯ kubectl foreach -q /kind/ -- get deployments --namespace nginx Will run command in context(s): - kind-1 - kind-2 - kind-3 kind-3 | NAME READY UP-TO-DATE AVAILABLE AGE kind-3 | nginx 1/1 1 1 114s kind-1 | NAME READY UP-TO-DATE AVAILABLE AGE kind-1 | nginx 1/1 1 1 114s kind-2 | NAME READY UP-TO-DATE AVAILABLE AGE kind-2 | nginx 1/1 1 1 114s
ログをまとめてみる
❯ kubectl foreach -q /kind/ -- logs -f -n nginx -l app=nginx Will run command in context(s): - kind-1 - kind-2 - kind-3 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: nginx/1.23.2 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6) kind-3 | 2022/11/30 14:10:10 [notice] 1#1: OS: Linux 5.10.124-linuxkit kind-3 | 2022/11/30 14:10:10 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker processes kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker process 32 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker process 33 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker process 34 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker process 35 kind-3 | 2022/11/30 14:10:10 [notice] 1#1: start worker process 36 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: nginx/1.23.2 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6) kind-2 | 2022/11/30 14:10:04 [notice] 1#1: OS: Linux 5.10.124-linuxkit kind-2 | 2022/11/30 14:10:04 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker processes kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker process 32 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker process 33 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker process 34 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker process 35 kind-2 | 2022/11/30 14:10:04 [notice] 1#1: start worker process 36 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: nginx/1.23.2 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6) kind-1 | 2022/11/30 14:09:46 [notice] 1#1: OS: Linux 5.10.124-linuxkit kind-1 | 2022/11/30 14:09:46 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker processes kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker process 32 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker process 33 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker process 34 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker process 35 kind-1 | 2022/11/30 14:09:46 [notice] 1#1: start worker process 36 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 15 (SIGTERM) received from 49, exiting
ここで Pod を kill してみた
kind-3 | 2022/11/30 14:19:13 [notice] 35#35: exiting kind-3 | 2022/11/30 14:19:13 [notice] 36#36: exiting kind-3 | 2022/11/30 14:19:13 [notice] 35#35: exit kind-3 | 2022/11/30 14:19:13 [notice] 36#36: exit kind-3 | 2022/11/30 14:19:13 [notice] 34#34: exiting kind-3 | 2022/11/30 14:19:13 [notice] 33#33: exiting kind-3 | 2022/11/30 14:19:13 [notice] 34#34: exit kind-3 | 2022/11/30 14:19:13 [notice] 33#33: exit kind-3 | 2022/11/30 14:19:13 [notice] 32#32: exiting kind-3 | 2022/11/30 14:19:13 [notice] 32#32: exit kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 17 (SIGCHLD) received from 35 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: worker process 35 exited with code 0 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 29 (SIGIO) received kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 17 (SIGCHLD) received from 33 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: worker process 33 exited with code 0 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: worker process 34 exited with code 0 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: worker process 36 exited with code 0 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 29 (SIGIO) received kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 17 (SIGCHLD) received from 36 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: signal 17 (SIGCHLD) received from 32 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: worker process 32 exited with code 0 kind-3 | 2022/11/30 14:19:13 [notice] 1#1: exit
利用シーン
- 複数の Kubernetes クラスタを運用しており、情報をまとめて確認したい場合
登場背景
気にすること
- Write系の処理は非常に怖いので、
-qはまずつけないこと - 公式より
This tool is not intended for deploying workloads to clusters, or using programmatically. Therefore, it does not provide a structured output format or ordered printing that is meant to be parsed by or piped to other programs (maybe except for grep).
このツールは、クラスタへのワークロードの展開や、プログラムによる使用を意図したものではありません。したがって、他のプログラムによって解析されたり、パイプでつながれたりすることを意図した、構造化された出力形式や順序付き印刷を提供しない（多分、grepは除く）。 by DeepL
