diff --git a/content/en/docs/tasks/debug-application-cluster/get-shell-running-container.md b/content/en/docs/tasks/debug-application-cluster/get-shell-running-container.md index 12502ef102..8535e9763c 100644 --- a/content/en/docs/tasks/debug-application-cluster/get-shell-running-container.md +++ b/content/en/docs/tasks/debug-application-cluster/get-shell-running-container.md @@ -9,7 +9,7 @@ content_type: task This page shows how to use `kubectl exec` to get a shell to a -running Container. +running container. @@ -17,16 +17,16 @@ running Container. ## {{% heading "prerequisites" %}} -{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}} +{{< include "task-tutorial-prereqs.md" >}} -## Getting a shell to a Container +## Getting a shell to a container -In this exercise, you create a Pod that has one Container. The Container +In this exercise, you create a Pod that has one container. The container runs the nginx image. Here is the configuration file for the Pod: {{< codenew file="application/shell-demo.yaml" >}} @@ -37,117 +37,121 @@ Create the Pod: kubectl apply -f https://k8s.io/examples/application/shell-demo.yaml ``` -Verify that the Container is running: +Verify that the container is running: ```shell kubectl get pod shell-demo ``` -Get a shell to the running Container: +Get a shell to the running container: ```shell -kubectl exec -it shell-demo -- /bin/bash +kubectl exec --stdin --tty shell-demo -- /bin/bash ``` + {{< note >}} - -The double dash symbol "--" is used to separate the arguments you want to pass to the command from the kubectl arguments. - +The double dash (`--`) separates the arguments you want to pass to the command from the kubectl arguments. {{< /note >}} In your shell, list the root directory: ```shell -root@shell-demo:/# ls / +# Run this inside the container +ls / ``` In your shell, experiment with other commands. Here are some examples: ```shell -root@shell-demo:/# ls / -root@shell-demo:/# cat /proc/mounts -root@shell-demo:/# cat /proc/1/maps -root@shell-demo:/# apt-get update -root@shell-demo:/# apt-get install -y tcpdump -root@shell-demo:/# tcpdump -root@shell-demo:/# apt-get install -y lsof -root@shell-demo:/# lsof -root@shell-demo:/# apt-get install -y procps -root@shell-demo:/# ps aux -root@shell-demo:/# ps aux | grep nginx +# You can run these example commands inside the container +ls / +cat /proc/mounts +cat /proc/1/maps +apt-get update +apt-get install -y tcpdump +tcpdump +apt-get install -y lsof +lsof +apt-get install -y procps +ps aux +ps aux | grep nginx ``` ## Writing the root page for nginx Look again at the configuration file for your Pod. The Pod -has an `emptyDir` volume, and the Container mounts the volume +has an `emptyDir` volume, and the container mounts the volume at `/usr/share/nginx/html`. In your shell, create an `index.html` file in the `/usr/share/nginx/html` directory: ```shell -root@shell-demo:/# echo Hello shell demo > /usr/share/nginx/html/index.html +# Run this inside the container +echo 'Hello shell demo' > /usr/share/nginx/html/index.html ``` In your shell, send a GET request to the nginx server: ```shell -root@shell-demo:/# apt-get update -root@shell-demo:/# apt-get install curl -root@shell-demo:/# curl localhost +# Run this in the shell inside your container +apt-get update +apt-get install curl +curl http://localhost/ ``` The output shows the text that you wrote to the `index.html` file: -```shell +``` Hello shell demo ``` When you are finished with your shell, enter `exit`. -## Running individual commands in a Container +```shell +exit # To quit the shell in the container +``` + +## Running individual commands in a container In an ordinary command window, not your shell, list the environment -variables in the running Container: +variables in the running container: ```shell kubectl exec shell-demo env ``` -Experiment running other commands. Here are some examples: +Experiment with running other commands. Here are some examples: ```shell -kubectl exec shell-demo ps aux -kubectl exec shell-demo ls / -kubectl exec shell-demo cat /proc/1/mounts +kubectl exec shell-demo -- ps aux +kubectl exec shell-demo -- ls / +kubectl exec shell-demo -- cat /proc/1/mounts ``` -## Opening a shell when a Pod has more than one Container +## Opening a shell when a Pod has more than one container -If a Pod has more than one Container, use `--container` or `-c` to -specify a Container in the `kubectl exec` command. For example, +If a Pod has more than one container, use `--container` or `-c` to +specify a container in the `kubectl exec` command. For example, suppose you have a Pod named my-pod, and the Pod has two containers -named main-app and helper-app. The following command would open a -shell to the main-app Container. +named _main-app_ and _helper-app_. The following command would open a +shell to the _main-app_ container. ```shell -kubectl exec -it my-pod --container main-app -- /bin/bash +kubectl exec -i -t my-pod --container main-app -- /bin/bash ``` - +{{< note >}} +The short options `-i` and `-t` are the same as the long options `--stdin` and `--tty` +{{< /note >}} ## {{% heading "whatsnext" %}} -* [kubectl exec](/docs/reference/generated/kubectl/kubectl-commands/#exec) - - - - - +* Read about [kubectl exec](/docs/reference/generated/kubectl/kubectl-commands/#exec)