kubectl for Docker Users

    To run an nginx Deployment and expose the Deployment, see . docker:

    1. 55c103fa129692154a7652490236fee9be47d70a8dd562281ae7d2f9a339a6db
    1. docker ps
    1. CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
    2. 55c103fa1296        nginx               "nginx -g 'daemon of…"   9 seconds ago       Up 9 seconds        0.0.0.0:80->80/tcp   nginx-app

    kubectl:

    1. # start the pod running nginx
    2. kubectl create deployment --image=nginx nginx-app
    1. deployment.apps/nginx-app created
    1. # add env to nginx-app
    2. kubectl set env deployment/nginx-app  DOMAIN=cluster
    1. deployment.apps/nginx-app env updated

    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.

    1. # expose a port through with a service
    2. kubectl expose deployment nginx-app --port=80 --name=nginx-http
    1. service "nginx-http" exposed

    By using kubectl, you can create a 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 with a selector that matches the pod labels. For more information, see Use a Service to Access an Application in a Cluster.

    By default images run in the background, similar to docker run -d .... To run things in the foreground, use to create pod:

    1. 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.

    docker ps

    To list what is currently running, see .

    docker:

    1. docker ps -a
    1. CONTAINER ID        IMAGE               COMMAND                  CREATED              STATUS                     PORTS                NAMES
    2. 14636241935f        ubuntu:16.04        "echo test"              5 seconds ago        Exited (0) 5 seconds ago                        cocky_fermi
    3. 55c103fa1296        nginx               "nginx -g 'daemon of…"   About a minute ago   Up About a minute          0.0.0.0:80->80/tcp   nginx-app

    kubectl:

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

    docker attach

    To attach a process that is already running in a container, see .

    docker:

    1. docker ps
    1. CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
    2. 55c103fa1296        nginx               "nginx -g 'daemon of…"   5 minutes ago       Up 5 minutes        0.0.0.0:80->80/tcp   nginx-app
    1. docker attach 55c103fa1296
    1. kubectl attach -it nginx-app-5jyvm
    2. ...

    To detach from the container, you can type the escape sequence Ctrl+P followed by Ctrl+Q.

    To execute a command in a container, see .

    docker:

    1. docker ps
    1. CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
    2. 55c103fa1296        nginx               "nginx -g 'daemon of…"   6 minutes ago       Up 6 minutes        0.0.0.0:80->80/tcp   nginx-app
    1. docker exec 55c103fa1296 cat /etc/hostname
    1. 55c103fa1296

    kubectl:

    1. kubectl get po
    1. NAME              READY     STATUS    RESTARTS   AGE
    2. nginx-app-5jyvm   1/1       Running   0          10m
    1. kubectl exec nginx-app-5jyvm -- cat /etc/hostname
    1. nginx-app-5jyvm

    To use interactive commands.

    docker:

    1. docker exec -ti 55c103fa1296 /bin/sh
    2. # exit

    kubectl:

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

    For more information, see Get a Shell to a Running Container.

    docker logs

    To follow stdout/stderr of a process that is running, see kubectl logs.

    docker:

    1. docker logs -f a9e
    1. 192.168.9.1 - - [14/Jul/2015:01:04:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"
    2. 192.168.9.1 - - [14/Jul/2015:01:04:03 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"

    kubectl:

    1. kubectl logs -f nginx-app-zibvs
    1. 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
    2. 10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
    1. kubectl logs --previous nginx-app-zibvs
    1. 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
    2. 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 .

    docker stop and docker rm

    To stop and delete a running process, see .

    docker:

    1. docker ps
    1. docker stop a9ec34d98787
    1. a9ec34d98787
    1. docker rm a9ec34d98787
    1. a9ec34d98787

    kubectl:

    1. kubectl get deployment nginx-app
    1. NAME         READY   UP-TO-DATE   AVAILABLE   AGE
    2. nginx-app    1/1     1            1           2m
    1. kubectl get po -l app=nginx-app
    1. kubectl delete deployment nginx-app
    1. deployment "nginx-app" deleted
    1. kubectl get po -l app=nginx-app
    2. # 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.

    There is no direct analog of docker login in kubectl. If you are interested in using Kubernetes with a private registry, see .

    docker version

    To get the version of client and server, see .

    docker:

    1. docker version
    1. Client version: 1.7.0
    2. Client API version: 1.19
    3. Go version (client): go1.4.2
    4. Git commit (client): 0baf609
    5. OS/Arch (client): linux/amd64
    6. Server version: 1.7.0
    7. Server API version: 1.19
    8. Go version (server): go1.4.2
    9. Git commit (server): 0baf609
    10. OS/Arch (server): linux/amd64

    kubectl:

    1. kubectl version
    1. 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"}
    2. 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 .

    docker:

    1. docker info
    1. Containers: 40
    2. Images: 168
    3. Storage Driver: aufs
    4.  Root Dir: /usr/local/google/docker/aufs
    5.  Backing Filesystem: extfs
    6.  Dirs: 248
    7.  Dirperm1 Supported: false
    8. Execution Driver: native-0.2
    9. Logging Driver: json-file
    10. Kernel Version: 3.13.0-53-generic
    11. Operating System: Ubuntu 14.04.2 LTS
    12. CPUs: 12
    13. Total Memory: 31.32 GiB
    14. Name: k8s-is-fun.mtv.corp.google.com
    15. ID: ADUV:GCYR:B3VJ:HMPO:LNPQ:KD5S:YKFQ:76VN:IANZ:7TFV:ZBF4:BYJO