面向 Docker 用户的 kubectl

您可以使用 Kubernetes 命令行工具 `kubectl` 与 API 服务器进行交互。如果您熟悉 Docker 命令行工具,则使用 kubectl 很简单。但是,Docker 命令和 kubectl 命令之间存在一些差异。以下部分显示了 Docker 子命令并描述了等效的 `kubectl` 命令。

docker run

要运行 nginx 部署并公开部署,请参阅 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

通过使用 kubectl,您可以创建一个 部署 以确保 N 个 pod 运行 nginx,其中 N 是规范中声明的副本数量,默认为 1。您还可以创建一个具有匹配 pod 标签的选择器的 服务。有关更多信息,请参阅 使用服务访问集群中的应用程序

默认情况下,映像在后台运行,类似于 `docker run -d ...`。要在前台运行事物,请使用 `kubectl run` 创建 pod。

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

与 `docker run ...` 不同,如果您指定 `--attach`,那么您将附加 `stdin`、`stdout` 和 `stderr`。您无法控制哪些流被附加(`docker -a ...`)。要从容器分离,您可以键入转义序列 Ctrl+P,然后键入 Ctrl+Q。

docker ps

要列出当前正在运行的内容,请参阅 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

要附加到容器中已运行的进程,请参阅 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
...

要从容器分离,您可以键入转义序列 Ctrl+P,然后键入 Ctrl+Q。

docker exec

要在容器中执行命令,请参阅 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

要使用交互式命令。

docker

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

kubectl

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

有关更多信息,请参阅 获取运行容器的 Shell

docker logs

要跟踪正在运行的进程的 stdout/stderr,请参阅 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 和容器之间存在细微的差异;默认情况下,pod 的进程退出时不会终止。相反,pod 会重新启动该进程。这类似于 docker run 选项 `--restart=always`,但有一个主要区别。在 docker 中,每个进程调用的输出都会被串联起来,但在 Kubernetes 中,每次调用都是独立的。要查看 Kubernetes 中先前运行的输出,请执行以下操作

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" "-"

有关更多信息,请参阅 日志记录体系结构

docker stop 和 docker rm

要停止和删除运行的进程,请参阅 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

kubectl 中没有 `docker login` 的直接对应项。如果您有兴趣将 Kubernetes 与私有注册表一起使用,请参阅 使用私有注册表

docker version

要获取客户端和服务器的版本,请参阅 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

要获取有关环境和配置的杂项信息,请参阅 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
最后修改时间:2024 年 8 月 8 日下午 4:19 PST:更新 docker-cli-to-kubectl.md,添加缺失的换行符 (b26372054e)