# List All Container Images Running in a Cluster

LLMS index: [llms.txt](/llms.txt)

---

<!-- overview -->

This page shows how to use kubectl to list all of the Container images
for Pods running in a cluster.

## Before you begin

<p>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
<a href="https://minikube.sigs.k8s.io/docs/tutorials/multi_node/">minikube</a>
or you can use one of these Kubernetes playgrounds:</p>
<ul>
<li><a href="https://labs.iximiuz.com/playgrounds?category=kubernetes&filter=all">iximiuz Labs</a></li>
<li><a href="https://killercoda.com/playgrounds/scenario/kubernetes">Killercoda</a></li>
<li><a href="https://kodekloud.com/public-playgrounds">KodeKloud</a></li>
</ul>
 
  <p>To check the version, enter  <code>kubectl version</code>.</p>


<!-- steps -->

In this exercise you will use kubectl to fetch all of the Pods
running in a cluster, and format the output to pull out the list
of Containers for each.

## List all Container images in all namespaces

- Fetch all Pods in all namespaces using `kubectl get pods --all-namespaces`
- Format the output to include only the list of Container image names
  using `-o jsonpath={.items[*].spec['initContainers', 'containers'][*].image}`.  This will recursively parse out the
  `image` field from the returned json.
  - See the [jsonpath reference](/docs/reference/kubectl/jsonpath/)
    for further information on how to use jsonpath.
- Format the output using standard tools: `tr`, `sort`, `uniq`
  - Use `tr` to replace spaces with newlines
  - Use `sort` to sort the results
  - Use `uniq` to aggregate image counts

```shell
kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec['initContainers', 'containers'][*].image}" |\
tr -s '[[:space:]]' '\n' |\
sort |\
uniq -c
```
The jsonpath is interpreted as follows:

- `.items[*]`: for each returned value
- `.spec`: get the spec
- `['initContainers', 'containers'][*]`: for each container
- `.image`: get the image


<div class="alert alert-info" role="note"><h4 class="alert-heading">Note:</h4>When fetching a single Pod by name, for example <code>kubectl get pod nginx</code>,
the <code>.items[*]</code> portion of the path should be omitted because a single
Pod is returned instead of a list of items.</div>


## List Container images by Pod

The formatting can be controlled further by using the `range` operation to
iterate over elements individually.

```shell
kubectl get pods --all-namespaces -o jsonpath='{range .items[*]}{"\n"}{.metadata.name}{":\t"}{range .spec.containers[*]}{.image}{", "}{end}{end}' |\
sort
```

## List Container images filtering by Pod label

To target only Pods matching a specific label, use the -l flag.  The
following matches only Pods with labels matching `app=nginx`.

```shell
kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}" -l app=nginx
```

## List Container images filtering by Pod namespace

To target only pods in a specific namespace, use the namespace flag. The
following matches only Pods in the `kube-system` namespace.

```shell
kubectl get pods --namespace kube-system -o jsonpath="{.items[*].spec.containers[*].image}"
```

## List Container images using a go-template instead of jsonpath

As an alternative to jsonpath, Kubectl supports using [go-templates](https://pkg.go.dev/text/template)
for formatting the output:

```shell
kubectl get pods --all-namespaces -o go-template --template="{{range .items}}{{range .spec.containers}}{{.image}} {{end}}{{end}}"
```

## What's next

### Reference

* [Jsonpath](/docs/reference/kubectl/jsonpath/) reference guide
* [Go template](https://pkg.go.dev/text/template) reference guide