---
approvers:
- caesarxuchao
- mikedanese
title: Get a Shell to a Running Container
---

{% capture overview %}

This page shows how to use `kubectl exec` to get a shell to a
running Container.

{% endcapture %}


{% capture prerequisites %}

{% include task-tutorial-prereqs.md %}

{% endcapture %}


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## Getting a shell to a 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:

{% include code.html language="yaml" file="shell-demo.yaml" ghlink="/docs/tasks/debug-application-cluster/shell-demo.yaml" %}

Create the Pod:

```shell
kubectl create -f https://k8s.io/docs/tasks/debug-application-cluster/shell-demo.yaml
```

Verify that the Container is running:

```shell
kubectl get pod shell-demo
```

Get a shell to the running Container:

```shell
kubectl exec -it shell-demo -- /bin/bash
```

In your shell, list the root directory:

```shell
root@shell-demo:/# 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
```

## 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
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
```

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
```

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

In an ordinary command window, not your shell, list the environment
variables in the running Container:

```shell
kubectl exec shell-demo env
```

Experiment 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
```

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{% capture discussion %}

## 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,
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.

```shell
kubectl exec -it my-pod --container main-app -- /bin/bash
```

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{% capture whatsnext %}

* [kubectl exec](/docs/user-guide/kubectl/{{page.version}}/#exec)

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{% include templates/task.md %}
