add create-kubeconfigs to warnet admin

I transmuted the setup_user_contexts.sh script into python code.

I also made it so that it would query all namespaces that start "warnet-" looking for service accounts,
and then create token credentials for those accounts.

Currently, user namespaces must start with "warnet-".

src/warnet/admin.py

@@ -1,4 +1,5 @@
 import os
+import subprocess
 from pathlib import Path
 
 import click
@@ -33,3 +34,132 @@ def init():
         f"[green]Copied network and namespace example files to {Path(current_dir) / NETWORK_DIR.name}[/green]"
     )
     richprint(f"[green]Created warnet project structure in {current_dir}[/green]")
+
+
+# Get kubectl values
+def get_kubectl_value(jsonpath):
+    return subprocess.check_output(
+        ["kubectl", "config", "view", "--minify", "-o", f"jsonpath={jsonpath}"]
+    ).decode("utf-8")
+
+
+# Get all namespaces that start with "warnet-"
+def get_warnet_namespaces():
+    namespaces = (
+        subprocess.check_output(
+            ["kubectl", "get", "namespaces", "-o", "jsonpath={.items[*].metadata.name}"]
+        )
+        .decode("utf-8")
+        .split()
+    )
+    return [ns for ns in namespaces if ns.startswith("warnet-")]
+
+
+# Get all service accounts for a given namespace
+def get_service_accounts(namespace):
+    return (
+        subprocess.check_output(
+            [
+                "kubectl",
+                "get",
+                "serviceaccounts",
+                "-n",
+                namespace,
+                "-o",
+                "jsonpath={.items[*].metadata.name}",
+            ]
+        )
+        .decode("utf-8")
+        .split()
+    )
+
+
+@admin.command()
+@click.option(
+    "--kubeconfig-dir",
+    default="kubeconfigs",
+    help="Directory to store kubeconfig files (default: kubeconfigs)",
+)
+@click.option(
+    "--token-duration",
+    default=172800,
+    type=int,
+    help="Duration of the token in seconds (default: 48 hours)",
+)
+def create_kubeconfigs(kubeconfig_dir, token_duration):
+    """Create kubeconfig files for all ServiceAccounts in namespaces starting with 'warnet-'."""
+    kubeconfig_dir = os.path.expanduser(kubeconfig_dir)
+
+    cluster_name = get_kubectl_value("{.clusters[0].name}")
+    cluster_server = get_kubectl_value("{.clusters[0].cluster.server}")
+    cluster_ca = get_kubectl_value("{.clusters[0].cluster.certificate-authority-data}")
+
+    os.makedirs(kubeconfig_dir, exist_ok=True)
+
+    # Get all namespaces that start with "warnet-"
+    warnet_namespaces = get_warnet_namespaces()
+
+    for namespace in warnet_namespaces:
+        click.echo(f"Processing namespace: {namespace}")
+        service_accounts = get_service_accounts(namespace)
+
+        for sa in service_accounts:
+            click.echo(f"Processing ServiceAccount: {sa}")
+
+            # Create a token for the ServiceAccount with specified duration
+            try:
+                token = (
+                    subprocess.check_output(
+                        [
+                            "kubectl",
+                            "create",
+                            "token",
+                            sa,
+                            "-n",
+                            namespace,
+                            f"--duration={token_duration}s",
+                        ]
+                    )
+                    .decode("utf-8")
+                    .strip()
+                )
+            except subprocess.CalledProcessError:
+                click.echo(f"Failed to create token for ServiceAccount {sa}. Skipping...")
+                continue
+
+            # Create a kubeconfig file for the user
+            kubeconfig_file = os.path.join(kubeconfig_dir, f"{sa}-{namespace}-kubeconfig")
+
+            kubeconfig_content = f"""apiVersion: v1
+kind: Config
+clusters:
+- name: {cluster_name}
+  cluster:
+    server: {cluster_server}
+    certificate-authority-data: {cluster_ca}
+users:
+- name: {sa}
+  user:
+    token: {token}
+contexts:
+- name: {sa}-{namespace}
+  context:
+    cluster: {cluster_name}
+    namespace: {namespace}
+    user: {sa}
+current-context: {sa}-{namespace}
+"""
+            with open(kubeconfig_file, "w") as f:
+                f.write(kubeconfig_content)
+
+            click.echo(f"Created kubeconfig file for {sa}: {kubeconfig_file}")
+            click.echo(f"Token duration: {token_duration} seconds")
+            click.echo(f"To use this config, run: kubectl --kubeconfig={kubeconfig_file} get pods")
+            click.echo("---")
+
+    click.echo(f"All kubeconfig files have been created in the '{kubeconfig_dir}' directory.")
+    click.echo("Distribute these files to the respective users.")
+    click.echo(
+        "Users can then use them with kubectl by specifying the --kubeconfig flag or by setting the KUBECONFIG environment variable."
+    )
+    click.echo(f"Note: The tokens will expire after {token_duration} seconds.")