const output = await ddClient.extension.host?.cli.exec("kubectl", [
  "get",
  "namespaces",
  "--no-headers",
  "-o",
  'custom-columns=":metadata.name"',
  "--context",
  "docker-desktop",
]);
```

## Persisting the kubeconfig file

Below there are different ways to persist and read the `kubeconfig` file from the host filesystem. Users can add, edit, or remove Kubernetes context to the `kubeconfig` file at any time.

> Warning
>
> The `kubeconfig` file is very sensitive and if found can give an attacker administrative access to the Kubernetes Cluster.

### Extension's backend container

If you need your extension to persist the `kubeconfig` file after it's been read, you can have a backend container that exposes an HTTP POST endpoint to store the content of the file either in memory or somewhere within the container filesystem. This way, if the user navigates out of the extension to another part of Docker Desktop and then comes back, you don't need to read the `kubeconfig` file again.

```typescript
export const updateKubeconfig = async () => {
  const kubeConfig = await ddClient.extension.host?.cli.exec("kubectl", [
    "config",
    "view",
    "--raw",
    "--minify",
    "--context",
    "docker-desktop",
  ]);
  if (kubeConfig?.stderr) {
    console.log("error", kubeConfig?.stderr);
    return false;
  }

  // call backend container to store the kubeconfig retrieved into the container's memory or filesystem
  try {
    await ddClient.extension.vm?.service?.post("/store-kube-config", {
      data: kubeConfig?.stdout,
    });
  } catch (err) {
    console.log("error", JSON.stringify(err));
  }
};
```

### Docker volume

Volumes are the preferred mechanism for persisting data generated by and used by Docker containers. You can make use of them to persist the `kubeconfig` file.
By persisting the `kubeconfig` in a volume you won't need to read the `kubeconfig` file again when the extension pane closes. This makes it ideal for persisting data when navigating out of the extension to other parts of Docker Desktop.

```typescript
const kubeConfig = await ddClient.extension.host?.cli.exec("kubectl", [
  "config",
  "view",
  "--raw",
  "--minify",
  "--context",
  "docker-desktop",
]);
if (kubeConfig?.stderr) {
  console.log("error", kubeConfig?.stderr);
  return false;
}

await ddClient.docker.cli.exec("run", [
  "--rm",
  "-v",
  "my-vol:/tmp",
  "alpine",
  "/bin/sh",
  "-c",
  `"touch /tmp/.kube/config && echo '${kubeConfig?.stdout}' > /tmp/.kube/config"`,
]);
```

### Extension's `localStorage`

`localStorage` is one of the mechanisms of a browser's web storage. It allows users to save data as key-value pairs in the browser for later use.
`localStorage` does not clear data when the browser (the extension pane) closes. This makes it ideal for persisting data when navigating out of the extension to other parts of Docker Desktop.

```typescript
localStorage.setItem("kubeconfig", kubeConfig);
```

```typescript
localStorage.getItem("kubeconfig");
```