website/content/en/docs/reference/kubectl/docker-cli-to-kubectl.md

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2016-02-10 20:29:07 +00:00
---
title: kubectl for Docker Users
content_template: templates/concept
reviewers:
2016-07-29 17:36:25 +00:00
- brendandburns
- thockin
2016-02-10 20:29:07 +00:00
---
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You can use the Kubernetes command line tool kubectl to interact with the API Server. Using kubectl is straightforward if you are familiar with the Docker command line tool. However, there are a few differences between the docker commands and the kubectl commands. The following sections show a docker sub-command and describe the equivalent kubectl command.
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## docker run
To run an nginx Deployment and expose the Deployment, see [kubectl run](/docs/reference/generated/kubectl/kubectl-commands/#run).
docker:
```shell
docker run -d --restart=always -e DOMAIN=cluster --name nginx-app -p 80:80 nginx
```
```
55c103fa129692154a7652490236fee9be47d70a8dd562281ae7d2f9a339a6db
```
```shell
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:
```shell
# start the pod running nginx
kubectl run --image=nginx nginx-app --port=80 --env="DOMAIN=cluster"
```
```
deployment "nginx-app" created
```
{{< note >}}
`kubectl` commands print the type and name of the resource created or mutated, which can then be used in subsequent commands. You can expose a new Service after a Deployment is created.
{{< /note >}}
```shell
# expose a port through with a service
kubectl expose deployment nginx-app --port=80 --name=nginx-http
```
```
service "nginx-http" exposed
```
By using kubectl, you can create a [Deployment](/docs/concepts/workloads/controllers/deployment/) to ensure that N pods are running nginx, where N is the number of replicas stated in the spec and defaults to 1. You can also create a [service](/docs/concepts/services-networking/service/) with a selector that matches the pod labels. For more information, see [Use a Service to Access an Application in a Cluster](/docs/tasks/access-application-cluster/service-access-application-cluster).
By default images run in the background, similar to `docker run -d ...`. To run things in the foreground, use:
```shell
kubectl run [-i] [--tty] --attach <name> --image=<image>
```
Unlike `docker run ...`, if you specify `--attach`, then you attach `stdin`, `stdout` and `stderr`. You cannot control which streams are attached (`docker -a ...`).
To detach from the container, you can type the escape sequence Ctrl+P followed by Ctrl+Q.
Because the kubectl run command starts a Deployment for the container, the Deployment restarts if you terminate the attached process by using Ctrl+C, unlike `docker run -it`.
To destroy the Deployment and its pods you need to run `kubectl delete deployment <name>`.
## docker ps
To list what is currently running, see [kubectl get](/docs/reference/generated/kubectl/kubectl-commands/#get).
docker:
```shell
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:
```shell
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
To attach a process that is already running in a container, see [kubectl attach](/docs/reference/generated/kubectl/kubectl-commands/#attach).
docker:
```shell
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
```
```shell
docker attach 55c103fa1296
...
```
kubectl:
```shell
kubectl get pods
```
```
NAME READY STATUS RESTARTS AGE
nginx-app-5jyvm 1/1 Running 0 10m
```
```shell
kubectl attach -it nginx-app-5jyvm
...
```
To detach from the container, you can type the escape sequence Ctrl+P followed by Ctrl+Q.
## docker exec
To execute a command in a container, see [kubectl exec](/docs/reference/generated/kubectl/kubectl-commands/#exec).
docker:
```shell
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
```
```shell
docker exec 55c103fa1296 cat /etc/hostname
```
```
55c103fa1296
```
kubectl:
```shell
kubectl get po
```
```
NAME READY STATUS RESTARTS AGE
nginx-app-5jyvm 1/1 Running 0 10m
```
```shell
kubectl exec nginx-app-5jyvm -- cat /etc/hostname
```
```
nginx-app-5jyvm
```
To use interactive commands.
docker:
```shell
docker exec -ti 55c103fa1296 /bin/sh
# exit
```
kubectl:
```shell
kubectl exec -ti nginx-app-5jyvm -- /bin/sh
# exit
```
For more information, see [Get a Shell to a Running Container](/docs/tasks/debug-application-cluster/get-shell-running-container/).
## docker logs
To follow stdout/stderr of a process that is running, see [kubectl logs](/docs/reference/generated/kubectl/kubectl-commands/#logs).
docker:
```shell
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:
```shell
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" "-"
```
There is a slight difference between pods and containers; by default pods do not terminate if their processes exit. Instead the pods restart the process. This is similar to the docker run option `--restart=always` with one major difference. In docker, the output for each invocation of the process is concatenated, but for Kubernetes, each invocation is separate. To see the output from a previous run in Kubernetes, do this:
```shell
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" "-"
```
For more information, see [Logging Architecture](/docs/concepts/cluster-administration/logging/).
## docker stop and docker rm
To stop and delete a running process, see [kubectl delete](/docs/reference/generated/kubectl/kubectl-commands/#delete).
docker:
```shell
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
```
```shell
docker stop a9ec34d98787
```
```
a9ec34d98787
```
```shell
docker rm a9ec34d98787
```
```
a9ec34d98787
```
kubectl:
```shell
kubectl get deployment nginx-app
```
```
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-app 1/1 1 1 2m
```
```shell
kubectl get po -l run=nginx-app
```
```
NAME READY STATUS RESTARTS AGE
nginx-app-2883164633-aklf7 1/1 Running 0 2m
```
```shell
kubectl delete deployment nginx-app
```
```
deployment "nginx-app" deleted
```
```shell
kubectl get po -l run=nginx-app
# Return nothing
```
{{< note >}}
When you use kubectl, you don't delete the pod directly. You have to first delete the Deployment that owns the pod. If you delete the pod directly, the Deployment recreates the pod.
{{< /note >}}
## docker login
There is no direct analog of `docker login` in kubectl. If you are interested in using Kubernetes with a private registry, see [Using a Private Registry](/docs/concepts/containers/images/#using-a-private-registry).
## docker version
To get the version of client and server, see [kubectl version](/docs/reference/generated/kubectl/kubectl-commands/#version).
docker:
```shell
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:
```shell
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
To get miscellaneous information about the environment and configuration, see [kubectl cluster-info](/docs/reference/generated/kubectl/kubectl-commands/#cluster-info).
docker:
```shell
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:
```shell
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
```
2018-11-28 12:55:28 +00:00
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