MCP Rewatch

import { spawn, ChildProcess } from 'child_process' import { ProcessConfig, ProcessInfo, ProcessStatus } from './types' import { LogBuffer } from './log-buffer' interface ManagedProcess { config: ProcessConfig process?: ChildProcess status: ProcessStatus pid?: number startTime?: Date logBuffer: LogBuffer error?: string } export class ProcessManager { private processes: Map<string, ManagedProcess> = new Map() constructor(processConfigs: Record<string, ProcessConfig>) { for (const [name, config] of Object.entries(processConfigs)) { this.processes.set(name, { config, status: 'stopped', logBuffer: new LogBuffer() }) } } async restart(name: string): Promise<{ success: boolean; logs: string[] }> { const managed = this.processes.get(name) if (!managed) { throw new Error(`Process '${name}' not found`) } await this.stop(name) managed.logBuffer.clear() await this.start(name) // Wait for the process to start up const startupDelay = managed.config.startupDelay || 3000 // Default 3 seconds await new Promise(resolve => setTimeout(resolve, startupDelay)) // Check if process is still running const isRunning = managed.status === 'running' const logs = managed.logBuffer.getLines(20) // Get initial logs return { success: isRunning, logs } } private async start(name: string): Promise<void> { const managed = this.processes.get(name) if (!managed) { throw new Error(`Process '${name}' not found`) } if (managed.status === 'running' || managed.status === 'starting') { return } managed.status = 'starting' managed.error = undefined try { const env = { ...process.env, ...managed.config.env } const proc = spawn(managed.config.command, managed.config.args, { cwd: managed.config.cwd || process.cwd(), env, shell: false, // Don't use shell to avoid shell syntax issues detached: process.platform !== 'win32' // Create new process group on Unix-like systems }) managed.process = proc managed.pid = proc.pid managed.startTime = new Date() // Listen for spawn event to confirm successful start proc.once('spawn', () => { managed.status = 'running' managed.logBuffer.add(`[system] Process started successfully (PID: ${proc.pid})`) }) proc.stdout?.on('data', (data) => { const lines = data.toString().split('\n').filter(Boolean) lines.forEach((line: string) => managed.logBuffer.add(`[stdout] ${line}`)) }) proc.stderr?.on('data', (data) => { const lines = data.toString().split('\n').filter(Boolean) lines.forEach((line: string) => managed.logBuffer.add(`[stderr] ${line}`)) }) proc.on('error', (error: any) => { managed.status = 'error' // Provide specific error messages based on error code if (error.code === 'ENOENT') { managed.error = `Command not found: ${managed.config.command}` managed.logBuffer.add(`[error] Command '${managed.config.command}' not found. Check if it's installed and in PATH.`) } else if (error.code === 'EACCES') { managed.error = `Permission denied: ${managed.config.command}` managed.logBuffer.add(`[error] Permission denied executing '${managed.config.command}'. Check file permissions.`) } else if (error.code === 'ENOTDIR') { managed.error = `Invalid working directory: ${managed.config.cwd}` managed.logBuffer.add(`[error] Working directory '${managed.config.cwd}' is not a directory.`) } else if (error.code === 'EMFILE') { managed.error = 'Too many open files' managed.logBuffer.add('[error] Too many open files. System limit reached.') } else { managed.error = error.message managed.logBuffer.add(`[error] Process error: ${error.message} (${error.code || 'unknown code'})`) } }) proc.on('exit', (code, signal) => { managed.status = 'stopped' managed.pid = undefined if (signal) { managed.logBuffer.add(`[exit] Process terminated by signal ${signal}`) } else if (code === 0) { managed.logBuffer.add('[exit] Process exited successfully (code 0)') } else { managed.logBuffer.add(`[exit] Process exited with code ${code}`) } }) } catch (error: any) { managed.status = 'error' // Handle spawn errors that might be thrown synchronously if (error.code === 'ENOENT') { managed.error = `Command not found: ${managed.config.command}` managed.logBuffer.add(`[error] Failed to spawn process: command '${managed.config.command}' not found`) } else { managed.error = error instanceof Error ? error.message : String(error) managed.logBuffer.add(`[error] Failed to spawn process: ${managed.error}`) } throw error } } async stop(name: string): Promise<void> { const managed = this.processes.get(name) if (!managed || !managed.process) { return } return new Promise((resolve, reject) => { const proc = managed.process! let killed = false let forceKillTimer: NodeJS.Timeout const cleanup = (reason: string) => { if (!killed) { killed = true clearTimeout(forceKillTimer) managed.process = undefined managed.pid = undefined managed.status = 'stopped' managed.logBuffer.add(`[system] Process stopped: ${reason}`) resolve() } } proc.once('exit', () => cleanup('graceful shutdown')) // Send SIGTERM for graceful shutdown try { // On Unix-like systems, kill the entire process group if (process.platform !== 'win32' && proc.pid) { process.kill(-proc.pid, 'SIGTERM') managed.logBuffer.add(`[system] Sent SIGTERM signal to process group ${proc.pid}`) } else { proc.kill('SIGTERM') managed.logBuffer.add('[system] Sent SIGTERM signal for graceful shutdown') } } catch (error: any) { managed.logBuffer.add(`[error] Failed to send SIGTERM: ${error.message}`) cleanup('kill failed') return } // Force kill after timeout (5 seconds) forceKillTimer = setTimeout(() => { if (!killed) { managed.logBuffer.add('[warning] Process did not respond to SIGTERM within 5 seconds, sending SIGKILL') try { // Kill entire process group on Unix-like systems if (process.platform !== 'win32' && proc.pid) { process.kill(-proc.pid, 'SIGKILL') managed.logBuffer.add(`[system] Sent SIGKILL to process group ${proc.pid}`) } else { proc.kill('SIGKILL') } } catch (error: any) { managed.logBuffer.add(`[error] Failed to send SIGKILL: ${error.message}`) } // Give it another second after SIGKILL setTimeout(() => cleanup('force killed'), 1000) } }, 5000) }) } async stopAll(): Promise<void> { const stopPromises = Array.from(this.processes.keys()).map(name => this.stop(name)) await Promise.all(stopPromises) } getLogs(name: string, lines?: number): string[] { const managed = this.processes.get(name) if (!managed) { throw new Error(`Process '${name}' not found`) } return managed.logBuffer.getLines(lines) } listProcesses(): ProcessInfo[] { return Array.from(this.processes.entries()).map(([name, managed]) => ({ name, status: managed.status, pid: managed.pid, startTime: managed.startTime, error: managed.error })) } // Expose processes for emergency cleanup getProcesses(): Map<string, ManagedProcess> { return this.processes } }