kubectl for Docker Users

您可以使用 Kubernetes 命令列工具 kubectl 與 API 伺服器互動。如果您熟悉 Docker 命令列工具，使用 kubectl 非常簡單。然而，Docker 命令與 kubectl 命令之間存在一些差異。以下章節顯示 Docker 子命令，並描述對應的 kubectl 命令。

docker run

若要執行 nginx Deployment 並公開 Deployment，請參閱 kubectl create deployment。

docker

docker run -d --restart=always -e DOMAIN=cluster --name nginx-app -p 80:80 nginx

55c103fa129692154a7652490236fee9be47d70a8dd562281ae7d2f9a339a6db

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
55c103fa1296        nginx               "nginx -g 'daemon of…"   9 seconds ago       Up 9 seconds        0.0.0.0:80->80/tcp   nginx-app

kubectl

# start the pod running nginx
kubectl create deployment --image=nginx nginx-app

deployment.apps/nginx-app created

# add env to nginx-app
kubectl set env deployment/nginx-app  DOMAIN=cluster

deployment.apps/nginx-app env updated

# expose a port through with a service
kubectl expose deployment nginx-app --port=80 --name=nginx-http

service "nginx-http" exposed

透過使用 kubectl，您可以建立 Deployment，以確保有 N 個 Pod 正在執行 nginx，其中 N 是規格中說明的副本數量，預設為 1。您也可以建立具有選擇器的 service，該選擇器符合 Pod 標籤。如需更多資訊，請參閱 使用服務存取叢集中的應用程式。

預設情況下，映像檔會在背景執行，類似於 docker run -d ...。若要在前景中執行，請使用 kubectl run 建立 Pod

kubectl run [-i] [--tty] --attach <name> --image=<image>

與 docker run ... 不同的是，如果您指定 --attach，則會附加 stdin、stdout 和 stderr。您無法控制要附加哪些串流 (docker -a ...)。若要從容器分離，您可以輸入跳脫序列 Ctrl+P，然後輸入 Ctrl+Q。

docker ps

若要列出目前正在執行的項目，請參閱 kubectl get。

docker

docker ps -a

CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS                     PORTS                NAMES
14636241935f        ubuntu:16.04        "echo test"              5 seconds ago        Exited (0) 5 seconds ago                        cocky_fermi
55c103fa1296        nginx               "nginx -g 'daemon of…"   About a minute ago   Up About a minute          0.0.0.0:80->80/tcp   nginx-app

kubectl

kubectl get po

NAME                        READY     STATUS      RESTARTS   AGE
nginx-app-8df569cb7-4gd89   1/1       Running     0          3m
ubuntu                      0/1       Completed   0          20s

docker attach

若要附加已在容器中執行的程序，請參閱 kubectl attach。

docker

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
55c103fa1296        nginx               "nginx -g 'daemon of…"   5 minutes ago       Up 5 minutes        0.0.0.0:80->80/tcp   nginx-app

docker attach 55c103fa1296
...

kubectl

kubectl get pods

NAME              READY     STATUS    RESTARTS   AGE
nginx-app-5jyvm   1/1       Running   0          10m

kubectl attach -it nginx-app-5jyvm
...

若要從容器分離，您可以輸入跳脫序列 Ctrl+P，然後輸入 Ctrl+Q。

docker exec

若要在容器中執行命令，請參閱 kubectl exec。

docker

docker ps

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
55c103fa1296        nginx               "nginx -g 'daemon of…"   6 minutes ago       Up 6 minutes        0.0.0.0:80->80/tcp   nginx-app

docker exec 55c103fa1296 cat /etc/hostname

55c103fa1296

kubectl

kubectl get po

NAME              READY     STATUS    RESTARTS   AGE
nginx-app-5jyvm   1/1       Running   0          10m

kubectl exec nginx-app-5jyvm -- cat /etc/hostname

nginx-app-5jyvm

使用互動式命令。

docker

docker exec -ti 55c103fa1296 /bin/sh
# exit

kubectl

kubectl exec -ti nginx-app-5jyvm -- /bin/sh
# exit

如需更多資訊，請參閱 取得執行中容器的 Shell。

docker logs

若要追蹤正在執行程序的 stdout/stderr，請參閱 kubectl logs。

docker

docker logs -f a9e

192.168.9.1 - - [14/Jul/2015:01:04:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"
192.168.9.1 - - [14/Jul/2015:01:04:03 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"

kubectl

kubectl logs -f nginx-app-zibvs

10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"

Pod 與容器之間存在些微差異；預設情況下，如果 Pod 的程序結束，Pod 不會終止。而是 Pod 會重新啟動程序。這類似於 Docker run 選項 --restart=always，但有一個主要差異。在 Docker 中，程序每次調用的輸出會串連在一起，但對於 Kubernetes 而言，每次調用都是獨立的。若要查看 Kubernetes 中先前執行的輸出，請執行以下操作

kubectl logs --previous nginx-app-zibvs

10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"

如需更多資訊，請參閱 日誌架構。

docker stop 和 docker rm

若要停止與刪除執行中的程序，請參閱 kubectl delete。

docker

docker ps

CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                         NAMES
a9ec34d98787        nginx               "nginx -g 'daemon of"  22 hours ago        Up 22 hours         0.0.0.0:80->80/tcp, 443/tcp   nginx-app

docker stop a9ec34d98787

a9ec34d98787

docker rm a9ec34d98787

a9ec34d98787

kubectl

kubectl get deployment nginx-app

NAME         READY   UP-TO-DATE   AVAILABLE   AGE
nginx-app    1/1     1            1           2m

kubectl get po -l app=nginx-app

NAME                         READY     STATUS    RESTARTS   AGE
nginx-app-2883164633-aklf7   1/1       Running   0          2m

kubectl delete deployment nginx-app

deployment "nginx-app" deleted

kubectl get po -l app=nginx-app
# Return nothing

docker login

在 kubectl 中沒有與 docker login 直接對應的項目。如果您有興趣將 Kubernetes 與私有登錄檔搭配使用，請參閱 使用私有登錄檔。

docker version

若要取得用戶端和伺服器的版本，請參閱kubectl version。

docker

docker version

Client version: 1.7.0
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 0baf609
OS/Arch (client): linux/amd64
Server version: 1.7.0
Server API version: 1.19
Go version (server): go1.4.2
Git commit (server): 0baf609
OS/Arch (server): linux/amd64

kubectl

kubectl version

Client Version: version.Info{Major:"1", Minor:"6", GitVersion:"v1.6.9+a3d1dfa6f4335", GitCommit:"9b77fed11a9843ce3780f70dd251e92901c43072", GitTreeState:"dirty", BuildDate:"2017-08-29T20:32:58Z", OpenPaasKubernetesVersion:"v1.03.02", GoVersion:"go1.7.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"6", GitVersion:"v1.6.9+a3d1dfa6f4335", GitCommit:"9b77fed11a9843ce3780f70dd251e92901c43072", GitTreeState:"dirty", BuildDate:"2017-08-29T20:32:58Z", OpenPaasKubernetesVersion:"v1.03.02", GoVersion:"go1.7.5", Compiler:"gc", Platform:"linux/amd64"}

docker info

若要取得關於環境和組態的各種資訊，請參閱kubectl cluster-info。

docker

docker info

Containers: 40
Images: 168
Storage Driver: aufs
 Root Dir: /usr/local/google/docker/aufs
 Backing Filesystem: extfs
 Dirs: 248
 Dirperm1 Supported: false
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 3.13.0-53-generic
Operating System: Ubuntu 14.04.2 LTS
CPUs: 12
Total Memory: 31.32 GiB
Name: k8s-is-fun.mtv.corp.google.com
ID: ADUV:GCYR:B3VJ:HMPO:LNPQ:KD5S:YKFQ:76VN:IANZ:7TFV:ZBF4:BYJO
WARNING: No swap limit support

kubectl

kubectl cluster-info

Kubernetes master is running at https://203.0.113.141
KubeDNS is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/kube-dns/proxy
kubernetes-dashboard is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
Grafana is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
Heapster is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-heapster/proxy
InfluxDB is running at https://203.0.113.141/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
最後修改時間：2024 年 8 月 8 日下午 4:19 PST：Update docker-cli-to-kubectl.md, add the missing newline (b26372054e)