# Get a Shell to a Running Container LLMS index: [llms.txt](/llms.txt) --- This page shows how to use `kubectl exec` to get a shell to a running container. ## Before you begin

You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

## 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:

    application/shell-demo.yaml
    
apiVersion: v1
kind: Pod
metadata:
  name: shell-demo
spec:
  volumes:
  - name: shared-data
    emptyDir: {}
  containers:
  - name: nginx
    image: nginx
    volumeMounts:
    - name: shared-data
      mountPath: /usr/share/nginx/html
  hostNetwork: true
  dnsPolicy: Default

Create the Pod: ```shell kubectl apply -f https://k8s.io/examples/application/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 --stdin --tty shell-demo -- /bin/bash ```

Note:

The double dash (--) separates the arguments you want to pass to the command from the kubectl arguments.

In your shell, list the root directory: ```shell # Run this inside the container ls / ``` In your shell, experiment with other commands. Here are some examples: ```shell # 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 at `/usr/share/nginx/html`. In your shell, create an `index.html` file in the `/usr/share/nginx/html` directory: ```shell # 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 # 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: ``` Hello shell demo ``` When you are finished with your shell, enter `exit`. ```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: ```shell kubectl exec shell-demo -- env ``` 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 ``` ## 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 -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

## What's next * Read about [kubectl exec](/docs/reference/generated/kubectl/kubectl-commands/#exec)