@cryptotaxi247 / netdata / commits / 215875e5c

deps(mcp/bridge/stdio-golang): switch to github.com/coder/websocket (#21006)

Ilya Mashchenko committed Sep 18, 2025 at 20:12 UTC 215875e5cfbddc88e22ec24384a81ffe2782a900

6 files changed +62 -62

src/web/mcp/bridges/stdio-golang/README.md

+3 -3

@@ -5,7 +5,7 @@ This Go bridge converts MCP stdio communication to Netdata's MCP over WebSocket.

5 ## Requirements

7 - Go 1.16+

8 -- nhooyr.io/websocket package

8 +- github.com/coder/websocket package

10 ## Installation

@@ -32,7 +32,7 @@ Alternatively, you can build it manually:

32 go mod init netdata/nd-mcp-bridge

34 # Add dependencies

35 -go get nhooyr.io/websocket

35 +go get github.com/coder/websocket

36 go mod tidy

38 # Build the binary

@@ -89,7 +89,7 @@ The reconnection algorithm starts with a 1-second delay and doubles the wait tim

89 ## Implementation Notes

91 This implementation:

92 -- Uses the nhooyr.io/websocket library for WebSocket communication

92 +- Uses the github.com/coder/websocket library for WebSocket communication

93 - Explicitly sets WebSocket headers including Sec-WebSocket-Key and Sec-WebSocket-Version

94 - Implements proper WebSocket handshake to ensure compatibility with Netdata's WebSocket server

95 - Sends and receives raw text messages directly (without JSON serialization/deserialization)

src/web/mcp/bridges/stdio-golang/build.bat

+1 -1

@@ -34,7 +34,7 @@ if not exist "go.mod" (

35 REM Add required dependencies

36 echo Adding dependencies...

37 -go get nhooyr.io/websocket

37 +go get github.com/coder/websocket

38 go mod tidy

40 REM Build the binary

src/web/mcp/bridges/stdio-golang/build.sh

+1 -1

@@ -27,7 +27,7 @@ fi

28 # Add required dependencies

29 echo "Adding dependencies..."

30 -go get nhooyr.io/websocket

30 +go get github.com/coder/websocket

31 go mod tidy

33 # Build the binary

src/web/mcp/bridges/stdio-golang/go.mod

+1 -1

@@ -2,4 +2,4 @@ module netdata/nd-mcp-bridge

3 go 1.24.0

5 -require nhooyr.io/websocket v1.8.17

5 +require github.com/coder/websocket v1.8.14

src/web/mcp/bridges/stdio-golang/go.sum

+2 -2

@@ -1,2 +1,2 @@

1 -nhooyr.io/websocket v1.8.17 h1:KEVeLJkUywCKVsnLIDlD/5gtayKp8VoCkksHCGGfT9Y=

2 -nhooyr.io/websocket v1.8.17/go.mod h1:rN9OFWIUwuxg4fR5tELlYC04bXYowCP9GX47ivo2l+c=

1 +github.com/coder/websocket v1.8.14 h1:9L0p0iKiNOibykf283eHkKUHHrpG7f65OE3BhhO7v9g=

2 +github.com/coder/websocket v1.8.14/go.mod h1:NX3SzP+inril6yawo5CQXx8+fk145lPDC6pumgx0mVg=

src/web/mcp/bridges/stdio-golang/nd-mcp.go

+54 -54

@@ -17,7 +17,7 @@ import (

17 "syscall"

18 "time"

20 - "nhooyr.io/websocket"

20 + "github.com/coder/websocket"

21 )

23 // Connection states

@@ -35,10 +35,10 @@ const (

36 // JSON-RPC 2.0 related structures

37 type JsonRpcMessage struct {

38 - JsonRpc string `json:"jsonrpc"`

39 - Id interface{} `json:"id,omitempty"`

40 - Method string `json:"method,omitempty"`

41 - Result interface{} `json:"result,omitempty"`

38 + JsonRpc string `json:"jsonrpc"`

39 + Id interface{} `json:"id,omitempty"`

40 + Method string `json:"method,omitempty"`

41 + Result interface{} `json:"result,omitempty"`

42 Error *JsonRpcError `json:"error,omitempty"`

43 }

@@ -80,10 +80,10 @@ func main() {

80 }

82 // Set up channels for communication

83 - stdinCh := make(chan string, 100) // Buffer stdin messages

84 - reconnectCh := make(chan struct{}, 1) // Signal for immediate reconnection

85 - doneCh := make(chan struct{}) // Signal for program termination

86 - stdinClosedCh := make(chan struct{}) // Signal that stdin is closed

83 + stdinCh := make(chan string, 100) // Buffer stdin messages

84 + reconnectCh := make(chan struct{}, 1) // Signal for immediate reconnection

85 + doneCh := make(chan struct{}) // Signal for program termination

86 + stdinClosedCh := make(chan struct{}) // Signal that stdin is closed

88 // Global state

89 var state int // Connection state

@@ -91,7 +91,7 @@ func main() {

91 var messageQueueMu sync.Mutex

92 messageQueue := []string{}

93 stdinActive := true

94 -

94 +

95 // Pending requests that are waiting for connection to be established

96 var pendingMu sync.Mutex

97 pendingRequests := make(map[interface{}]*PendingRequest)

@@ -136,7 +136,7 @@ func main() {

136 pendingMu.Lock()

137 if req, exists := pendingRequests[msgId]; exists {

138 fmt.Fprintf(os.Stderr, "%s: Connection timeout for request ID %v, sending error response\n", programName, msgId)

139 -

139 +

140 // Create and send error response

141 errorResponse := createJsonRpcError(

142 msgId,

@@ -144,16 +144,16 @@ func main() {

144 "MCP server connection failed",

145 map[string]string{"details": "Could not establish connection to Netdata within timeout period"},

146 )

147 -

147 +

148 fmt.Println(errorResponse)

149 -

149 +

150 // Get the original message

151 originalMessage := req.Message

152 -

152 +

153 // Remove request from pending

154 delete(pendingRequests, msgId)

155 pendingMu.Unlock()

156 -

156 +

157 // Also remove from messageQueue if it exists there

158 messageQueueMu.Lock()

159 for i, msg := range messageQueue {

@@ -191,23 +191,23 @@ func main() {

191 go func() {

192 scanner := bufio.NewScanner(os.Stdin)

193 scannerRunning := true

194 -

194 +

195 // Make scanner buffer larger to handle large messages

196 const maxScanBufferSize = 1024 * 1024 // 1MB

197 buf := make([]byte, maxScanBufferSize)

198 scanner.Buffer(buf, maxScanBufferSize)

199 -

199 +

200 for scannerRunning && scanner.Scan() {

201 text := scanner.Text()

202 -

202 +

203 // Parse for JSON-RPC ID

204 msgId, _ := parseJsonRpcMessage(text)

205 -

205 +

206 // Check connection state

207 stateMu.Lock()

208 currentState := state

209 stateMu.Unlock()

210 -

210 +

211 if currentState != stateConnected && msgId != nil {

212 // Store as pending request with timeout

213 pendingMu.Lock()

@@ -218,13 +218,13 @@ func main() {

218 }

219 pendingRequests[msgId] = req

220 pendingMu.Unlock()

221 -

221 +

222 fmt.Fprintf(os.Stderr, "%s: Received request with ID %v, setting response timeout\n", programName, msgId)

223 }

224 -

224 +

225 // Queue the message

226 stdinCh <- text

227 -

227 +

228 // If we're not connected, trigger immediate reconnection

229 if currentState != stateConnected {

230 select {

@@ -235,14 +235,14 @@ func main() {

235 }

236 }

237 }

238 -

238 +

239 // Check for scanner error

240 if err := scanner.Err(); err != nil {

241 fmt.Fprintf(os.Stderr, "%s: ERROR: stdin read error: %v\n", programName, err)

242 } else {

243 fmt.Fprintf(os.Stderr, "%s: End of stdin\n", programName)

244 }

245 -

245 +

246 // Signal that stdin is closed

247 stdinActive = false

248 close(stdinClosedCh)

@@ -252,10 +252,10 @@ func main() {

252 baseDelay := 1 * time.Second

253 maxDelay := 60 * time.Second

254 attempt := 0

255 -

255 +

256 // Timer for reconnection backoff

257 var timer *time.Timer

258 -

258 +

259 // Main connection loop

260 for {

261 select {

@@ -271,12 +271,12 @@ func main() {

271 if timer != nil {

272 timer.Stop()

273 }

274 -

274 +

275 // Only proceed with immediate reconnection if we're not already connecting/connected

276 stateMu.Lock()

277 currentState := state

278 stateMu.Unlock()

279 -

279 +

280 if currentState == stateDisconnected {

281 // Reset the reconnection timer

282 attempt = 0

@@ -293,17 +293,17 @@ func main() {

293 fmt.Fprintf(os.Stderr, "%s: Stdin closed and disconnected, exiting\n", programName)

294 return

295 }

296 -

296 +

297 delaySeconds := math.Min(float64(maxDelay.Seconds()),

298 float64(baseDelay.Seconds())*math.Pow(2, float64(attempt-1))*(0.5+jitter()))

299 delay := time.Duration(delaySeconds * float64(time.Second))

300 -

300 +

301 fmt.Fprintf(os.Stderr, "%s: Reconnecting in %.1f seconds (attempt %d)...\n",

302 programName, delaySeconds, attempt)

303 -

303 +

304 // Create timer and wait for it to expire, or for signals

305 timer = time.NewTimer(delay)

306 -

306 +

307 select {

308 case <-timer.C:

309 // Timer expired, continue to connection attempt

@@ -330,7 +330,7 @@ func main() {

330

331 // Set up connection context with cancellation

332 ctx, cancel := context.WithCancel(context.Background())

333 -

333 +

334 // Set up connection timeout

335 connectionCtx, connectionCancel := context.WithTimeout(ctx, 15*time.Second)

336 defer connectionCancel()

@@ -347,15 +347,15 @@ func main() {

347 CompressionMode: websocket.CompressionContextTakeover,

348 HTTPHeader: header,

349 })

350 -

350 +

351 // Connection failed

352 if err != nil {

353 fmt.Fprintf(os.Stderr, "%s: ERROR: websocket connection failed: %v\n", programName, err)

354 cancel()

355 -

355 +

356 // Increment attempt counter and try again

357 attempt++

358 -

358 +

359 // Update state to disconnected

360 stateMu.Lock()

361 state = stateDisconnected

@@ -400,7 +400,7 @@ func main() {

400 messageQueue = nil // Clear the queue

401 }

402 messageQueueMu.Unlock()

403 -

403 +

404 // Memory management: Limit size of pendingRequests to prevent memory leaks

405 pendingMu.Lock()

406 if len(pendingRequests) > 1000 {

@@ -413,10 +413,10 @@ func main() {

413

414 // Signal for connection closure

415 connClosed := make(chan struct{})

416 -

416 +

417 // Create wait group for goroutines

418 var wg sync.WaitGroup

419 -

419 +

420 // Goroutine for handling termination signals during connection

421 wg.Add(1)

422 go func() {

@@ -435,7 +435,7 @@ func main() {

435 return

436 }

437 }()

438 -

438 +

439 // Goroutine for sending messages to websocket

440 wg.Add(1)

441 go func() {

@@ -456,14 +456,14 @@ func main() {

456 if err != nil {

457 // Check if this was a message with ID

458 msgId, _ := parseJsonRpcMessage(msg)

459 -

459 +

460 select {

461 case <-connClosed:

462 // Connection already known to be closed, queue the message

463 messageQueueMu.Lock()

464 messageQueue = append(messageQueue, msg)

465 messageQueueMu.Unlock()

466 -

466 +

467 // If the message had an ID, keep the pending status

468 if msgId != nil {

469 pendingMu.Lock()

@@ -483,7 +483,7 @@ func main() {

483 messageQueueMu.Lock()

484 messageQueue = append(messageQueue, msg)

485 messageQueueMu.Unlock()

486 -

486 +

487 // Same ID handling as above

488 if msgId != nil {

489 pendingMu.Lock()

@@ -523,7 +523,7 @@ func main() {

523 go func() {

524 defer wg.Done()

525 defer close(connClosed)

526 -

526 +

527 for {

528 messageType, message, err := conn.Read(ctx)

529 if err != nil {

@@ -533,10 +533,10 @@ func main() {

533 }

534 return

535 }

536 -

536 +

537 if messageType == websocket.MessageText {

538 fmt.Println(string(message))

539 -

539 +

540 // Check if this is a response to a request with an ID

541 var response JsonRpcMessage

542 if err := json.Unmarshal(message, &response); err == nil && response.JsonRpc == "2.0" && response.Id != nil {

@@ -561,7 +561,7 @@ func main() {

561 defer wg.Done()

562 ticker := time.NewTicker(pingInterval)

563 defer ticker.Stop()

564 -

564 +

565 for {

566 select {

567 case <-ticker.C:

@@ -581,26 +581,26 @@ func main() {

581

582 // Wait for connection closed

583 <-connClosed

584 -

584 +

585 // Update state to disconnected

586 stateMu.Lock()

587 state = stateDisconnected

588 stateMu.Unlock()

589 -

589 +

590 // Clean up

591 cancel()

592 wg.Wait()

593 -

593 +

594 // Don't automatically reconnect if stdin closed and no messages in queue

595 messageQueueMu.Lock()

596 hasMessages := len(messageQueue) > 0

597 messageQueueMu.Unlock()

598 -

598 +

599 if !stdinActive && !hasMessages {

600 fmt.Fprintf(os.Stderr, "%s: Stdin closed and no pending messages, exiting\n", programName)

601 return

602 }

603 -

603 +

604 // Increment attempt counter for next reconnection

605 attempt++

606 }

@@ -613,4 +613,4 @@ func jitter() float64 {

613 return 0.5 // Fall back to 0.5 if there's an error

614 }

615 return float64(n.Int64()) / 1000.0

616 -}

\ No newline at end of file

616 +}