fix: logs command resolves server names, proper replica handling

- `mcpctl logs <server-name>` resolves to first RUNNING instance
- `mcpctl logs <server-name> -i <N>` selects specific replica
- Shows "instance N/M" hint when server has multiple replicas
- Added 5 proper tests: server name resolution, RUNNING preference,
  replica selection, out-of-range error, no instances error

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cli/src/commands/logs.ts

@@ -6,31 +6,65 @@ export interface LogsCommandDeps {
   log: (...args: unknown[]) => void;
 }
 
+interface InstanceInfo {
+  id: string;
+  status: string;
+  containerId: string | null;
+}
+
 /**
  * Resolve a name/ID to an instance ID.
  * Accepts: instance ID, server name, or server ID.
- * For servers, picks the first RUNNING instance.
+ * For servers with multiple replicas, picks by --instance index or first RUNNING.
  */
-async function resolveInstanceId(client: ApiClient, nameOrId: string): Promise<string> {
+async function resolveInstance(
+  client: ApiClient,
+  nameOrId: string,
+  instanceIndex?: number,
+): Promise<{ instanceId: string; serverName?: string; replicaInfo?: string }> {
   // Try as instance ID first
   try {
     await client.get(`/api/v1/instances/${nameOrId}`);
-    return nameOrId;
+    return { instanceId: nameOrId };
   } catch {
     // Not a valid instance ID
   }
 
-  // Try as server name → find its instances
+  // Try as server name/ID → find its instances
   const servers = await client.get<Array<{ id: string; name: string }>>('/api/v1/servers');
   const server = servers.find((s) => s.name === nameOrId || s.id === nameOrId);
-  if (server) {
+  if (!server) {
-    const instances = await client.get<Array<{ id: string; status: string }>>(`/api/v1/instances?serverId=${server.id}`);
+    throw new Error(`Instance or server '${nameOrId}' not found`);
-    const running = instances.find((i) => i.status === 'RUNNING') ?? instances[0];
-    if (running) return running.id;
-    throw new Error(`No instances found for server '${nameOrId}'`);
   }
 
-  throw new Error(`Instance or server '${nameOrId}' not found`);
+  const instances = await client.get<InstanceInfo[]>(`/api/v1/instances?serverId=${server.id}`);
+  if (instances.length === 0) {
+    throw new Error(`No instances found for server '${server.name}'`);
+  }
+
+  // Select by index or pick first running
+  let selected: InstanceInfo | undefined;
+  if (instanceIndex !== undefined) {
+    if (instanceIndex < 0 || instanceIndex >= instances.length) {
+      throw new Error(`Instance index ${instanceIndex} out of range (server '${server.name}' has ${instances.length} instance${instances.length > 1 ? 's' : ''})`);
+    }
+    selected = instances[instanceIndex];
+  } else {
+    selected = instances.find((i) => i.status === 'RUNNING') ?? instances[0];
+  }
+
+  if (!selected) {
+    throw new Error(`No instances found for server '${server.name}'`);
+  }
+
+  const result: { instanceId: string; serverName?: string; replicaInfo?: string } = {
+    instanceId: selected.id,
+    serverName: server.name,
+  };
+  if (instances.length > 1) {
+    result.replicaInfo = `instance ${instances.indexOf(selected) + 1}/${instances.length}`;
+  }
+  return result;
 }
 
 export function createLogsCommand(deps: LogsCommandDeps): Command {
@@ -40,8 +74,15 @@ export function createLogsCommand(deps: LogsCommandDeps): Command {
     .description('Get logs from an MCP server instance')
     .argument('<name>', 'Server name, server ID, or instance ID')
     .option('-t, --tail <lines>', 'Number of lines to show')
-    .action(async (nameOrId: string, opts: { tail?: string }) => {
+    .option('-i, --instance <index>', 'Instance/replica index (0-based, for servers with multiple replicas)')
-      const instanceId = await resolveInstanceId(client, nameOrId);
+    .action(async (nameOrId: string, opts: { tail?: string; instance?: string }) => {
+      const instanceIndex = opts.instance !== undefined ? parseInt(opts.instance, 10) : undefined;
+      const { instanceId, serverName, replicaInfo } = await resolveInstance(client, nameOrId, instanceIndex);
+
+      if (replicaInfo) {
+        process.stderr.write(`Showing logs for ${serverName} (${replicaInfo})\n`);
+      }
+
       let url = `/api/v1/instances/${instanceId}/logs`;
       if (opts.tail) {
         url += `?tail=${opts.tail}`;

src/cli/tests/commands/instances.test.ts

@@ -68,16 +68,79 @@ describe('logs command', () => {
     output = [];
   });
 
-  it('shows logs', async () => {
+  it('shows logs by instance ID', async () => {
-    vi.mocked(client.get).mockResolvedValue({ stdout: 'hello world\n', stderr: '' });
+    vi.mocked(client.get)
+      .mockResolvedValueOnce({ id: 'inst-1', status: 'RUNNING' } as never) // instance lookup
+      .mockResolvedValueOnce({ stdout: 'hello world\n', stderr: '' } as never); // logs
     const cmd = createLogsCommand({ client, log });
     await cmd.parseAsync(['inst-1'], { from: 'user' });
+    expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-1');
     expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-1/logs');
     expect(output.join('\n')).toContain('hello world');
   });
 
+  it('resolves server name to instance ID', async () => {
+    vi.mocked(client.get)
+      .mockRejectedValueOnce(new Error('not found')) // instance lookup fails
+      .mockResolvedValueOnce([{ id: 'srv-1', name: 'my-grafana' }] as never) // servers list
+      .mockResolvedValueOnce([{ id: 'inst-1', status: 'RUNNING', containerId: 'abc' }] as never) // instances for server
+      .mockResolvedValueOnce({ stdout: 'grafana logs\n', stderr: '' } as never); // logs
+    const cmd = createLogsCommand({ client, log });
+    await cmd.parseAsync(['my-grafana'], { from: 'user' });
+    expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-1/logs');
+    expect(output.join('\n')).toContain('grafana logs');
+  });
+
+  it('picks RUNNING instance over others', async () => {
+    vi.mocked(client.get)
+      .mockRejectedValueOnce(new Error('not found'))
+      .mockResolvedValueOnce([{ id: 'srv-1', name: 'ha-mcp' }] as never)
+      .mockResolvedValueOnce([
+        { id: 'inst-err', status: 'ERROR', containerId: null },
+        { id: 'inst-ok', status: 'RUNNING', containerId: 'abc' },
+      ] as never)
+      .mockResolvedValueOnce({ stdout: 'running instance\n', stderr: '' } as never);
+    const cmd = createLogsCommand({ client, log });
+    await cmd.parseAsync(['ha-mcp'], { from: 'user' });
+    expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-ok/logs');
+  });
+
+  it('selects specific replica with --instance', async () => {
+    vi.mocked(client.get)
+      .mockRejectedValueOnce(new Error('not found'))
+      .mockResolvedValueOnce([{ id: 'srv-1', name: 'ha-mcp' }] as never)
+      .mockResolvedValueOnce([
+        { id: 'inst-0', status: 'RUNNING', containerId: 'a' },
+        { id: 'inst-1', status: 'RUNNING', containerId: 'b' },
+      ] as never)
+      .mockResolvedValueOnce({ stdout: 'replica 1\n', stderr: '' } as never);
+    const cmd = createLogsCommand({ client, log });
+    await cmd.parseAsync(['ha-mcp', '-i', '1'], { from: 'user' });
+    expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-1/logs');
+  });
+
+  it('throws on out-of-range --instance index', async () => {
+    vi.mocked(client.get)
+      .mockRejectedValueOnce(new Error('not found'))
+      .mockResolvedValueOnce([{ id: 'srv-1', name: 'ha-mcp' }] as never)
+      .mockResolvedValueOnce([{ id: 'inst-0', status: 'RUNNING' }] as never);
+    const cmd = createLogsCommand({ client, log });
+    await expect(cmd.parseAsync(['ha-mcp', '-i', '5'], { from: 'user' })).rejects.toThrow('out of range');
+  });
+
+  it('throws when server has no instances', async () => {
+    vi.mocked(client.get)
+      .mockRejectedValueOnce(new Error('not found'))
+      .mockResolvedValueOnce([{ id: 'srv-1', name: 'empty-srv' }] as never)
+      .mockResolvedValueOnce([] as never);
+    const cmd = createLogsCommand({ client, log });
+    await expect(cmd.parseAsync(['empty-srv'], { from: 'user' })).rejects.toThrow('No instances found');
+  });
+
   it('passes tail option', async () => {
-    vi.mocked(client.get).mockResolvedValue({ stdout: '', stderr: '' });
+    vi.mocked(client.get)
+      .mockResolvedValueOnce({ id: 'inst-1' } as never)
+      .mockResolvedValueOnce({ stdout: '', stderr: '' } as never);
     const cmd = createLogsCommand({ client, log });
     await cmd.parseAsync(['inst-1', '-t', '50'], { from: 'user' });
     expect(client.get).toHaveBeenCalledWith('/api/v1/instances/inst-1/logs?tail=50');