OCM MCP Server

Instructions

Implementation Reference

• python/multicluster_mcp_server/tools/kubectl.py:22-66 (handler)

  Python MCP tool handler for 'kubectl': executes kubectl commands or applies YAML manifests with cluster-specific kubeconfig handling, validation, and error management.
  @mcp.tool(description="Securely run a kubectl command or apply YAML. Provide either 'command' or 'yaml'.") def kube_executor( cluster: Annotated[str, Field(description="The cluster name in a multi-cluster environment. Defaults to the hub cluster.")] = "default", command: Annotated[Optional[str], Field(description="The full kubectl command to execute. Must start with 'kubectl'.")] = None, yaml: Annotated[Optional[str], Field(description="YAML configuration to apply, provided as a string.")] = None, ) -> Annotated[str, Field(description="The execution result")]: try: if not command and not yaml: raise ValueError("Either 'command' or 'yaml' must be provided.") if command and yaml: raise ValueError("Provide only one of 'command' or 'yaml', not both.") kubeconfig_file = None if cluster and cluster != "default": kubeconfig_file = get_kubeconfig_file(cluster) if not validate_kubeconfig_file(kubeconfig_file): kubeconfig_file = setup_cluster_access(cluster=cluster) if not kubeconfig_file: raise FileNotFoundError(f"KUBECONFIG for cluster '{cluster}' does not exist.") if command: if not isinstance(command, str) or not is_valid_kubectl_command(command): raise ValueError("Invalid command: Only 'kubectl' commands are allowed.") final_command = command else: # Write YAML to a temp file if not isinstance(yaml, str) or not yaml.strip(): raise ValueError("Invalid YAML content.") with tempfile.NamedTemporaryFile("w", delete=False, suffix=".yaml") as temp_file: temp_file.write(yaml) temp_file_path = temp_file.name final_command = f"kubectl apply -f {temp_file_path}" # Add --kubeconfig if needed if kubeconfig_file: final_command = inject_kubeconfig(final_command, kubeconfig_file) print(f"[debug] Executing: {final_command}") result = subprocess.run(final_command, shell=True, capture_output=True, text=True, timeout=10) output = result.stdout or result.stderr or "Run kube executor successfully, but no output returned." return output except Exception as e: return f"Error running kube executor: {str(e)}"
• src/tools/kubectl.ts:34-86 (handler)

  TypeScript MCP tool handler for 'kubectl': executes kubectl commands or applies YAML via stdin with cluster kubeconfig injection and validation.
  export async function kubectl({ command, cluster, yaml, }: { command?: string; yaml?: string; cluster?: string; }): Promise<CallToolResult> { try { if (!command && !yaml) { throw new Error("Either 'command' or 'yaml' must be provided."); } if (command && yaml) { throw new Error("Provide only one of 'command' or 'yaml', not both."); } const kubeConfigFile = await getKubeconfigFile(cluster); let stdout = ""; let stderr = ""; if (command) { if (typeof command !== "string" || !isValidKubectlCommand(command)) { throw new Error("Invalid command: Only 'kubectl' commands are allowed."); } const finalCommand = kubeConfigFile ? `${command} --kubeconfig=${kubeConfigFile}` : command; const result = await execPromise(finalCommand); stdout = result.stdout; stderr = result.stderr; } else if (yaml) { stdout = await applyYaml(yaml, kubeConfigFile) } return { content: [{ type: "text", text: stdout?.trim() || stderr?.trim() || "Run kubectl successfully, but no output returned.", }], }; } catch (err: any) { return { content: [{ type: "text", text: `Error running kubectl: ${err.message || String(err)}`, }], }; } }
• src/index.ts:37-42 (registration)

  TypeScript MCP server registration of the 'kubectl' tool using McpServer.tool().
  server.tool( "kubectl", kubectlDesc, kubectlArgs, async (args, extra) => kubectl(args) // ensure connectCluster matches (args, extra) => ... )
• src/tools/kubectl.ts:20-32 (schema)

  TypeScript Zod schema definition for 'kubectl' tool arguments and description.
  export const kubectlDesc = "Securely run a kubectl command or apply YAML. Provide either 'command' or 'yaml'."; export const kubectlArgs = { command: z .string() .describe("The full kubectl command to execute. Must start with 'kubectl'."), yaml: z .string() .describe("YAML configuration to apply, provided as a string."), cluster: z .string() .describe("The cluster name in a multi-cluster environment. Defaults to the hub cluster.") .default("default"), };
• src/tools/kubectl.ts:11-12 (helper)

  Helper function to validate if a command is a valid kubectl command (shared pattern in both implementations).
  // Validate that the command starts with "kubectl" export function isValidKubectlCommand(command: string): boolean {