HealthEndpoint.ts•7.69 kB
import { createServer, IncomingMessage, ServerResponse } from 'http';
import { Logger } from '../utils/logger.js';
import { HealthChecker } from './HealthChecker.js';
export interface HealthEndpointConfig {
port: number;
host: string;
enabled: boolean;
path: string;
}
export class HealthEndpoint {
private static instance: HealthEndpoint | null = null;
private logger: Logger;
private server: ReturnType<typeof createServer> | null = null;
private config: HealthEndpointConfig;
private healthChecker: HealthChecker;
private constructor(config: HealthEndpointConfig) {
this.logger = Logger.getInstance();
this.config = config;
this.healthChecker = HealthChecker.getInstance();
}
static getInstance(config?: HealthEndpointConfig): HealthEndpoint {
if (!HealthEndpoint.instance) {
const defaultConfig: HealthEndpointConfig = {
port: 8080,
host: '127.0.0.1',
enabled: false,
path: '/health'
};
HealthEndpoint.instance = new HealthEndpoint(config || defaultConfig);
}
return HealthEndpoint.instance;
}
/**
* ヘルスチェックエンドポイントを開始
*/
async start(): Promise<void> {
if (!this.config.enabled) {
this.logger.debug('Health endpoint is disabled');
return;
}
if (this.server) {
this.logger.warn('Health endpoint is already running');
return;
}
try {
this.server = createServer((req, res) => {
this.handleRequest(req, res);
});
await new Promise<void>((resolve, reject) => {
this.server!.listen(this.config.port, this.config.host, () => {
this.logger.info('Health endpoint started', {
host: this.config.host,
port: this.config.port,
path: this.config.path
});
resolve();
});
this.server!.on('error', (error) => {
this.logger.error('Failed to start health endpoint', { error });
reject(error);
});
});
} catch (error) {
this.logger.error('Health endpoint startup failed', { error });
throw error;
}
}
/**
* ヘルスチェックエンドポイントを停止
*/
async stop(): Promise<void> {
if (!this.server) {
return;
}
try {
await new Promise<void>((resolve) => {
this.server!.close(() => {
this.logger.info('Health endpoint stopped');
resolve();
});
});
this.server = null;
} catch (error) {
this.logger.error('Failed to stop health endpoint', { error });
}
}
/**
* 設定を更新
*/
updateConfig(config: Partial<HealthEndpointConfig>): void {
this.config = { ...this.config, ...config };
}
/**
* エンドポイントが動作中かどうか
*/
isRunning(): boolean {
return this.server !== null;
}
/**
* HTTPリクエストを処理
*/
private async handleRequest(req: IncomingMessage, res: ServerResponse): Promise<void> {
const url = req.url;
const method = req.method;
// CORS ヘッダーを設定
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
// OPTIONS リクエスト（プリフライト）
if (method === 'OPTIONS') {
res.writeHead(200);
res.end();
return;
}
// ヘルスチェックエンドポイント
if (method === 'GET' && url === this.config.path) {
await this.handleHealthCheck(res);
return;
}
// 詳細ヘルスレポート
if (method === 'GET' && url === `${this.config.path}/detailed`) {
await this.handleDetailedHealthCheck(res);
return;
}
// メトリクス（Prometheus形式）
if (method === 'GET' && url === '/metrics') {
await this.handleMetrics(res);
return;
}
// 404 Not Found
this.sendResponse(res, 404, {
error: 'Not Found',
message: `Path ${url} not found`,
availableEndpoints: [
this.config.path,
`${this.config.path}/detailed`,
'/metrics'
]
});
}
/**
* 基本的なヘルスチェック
*/
private async handleHealthCheck(res: ServerResponse): Promise<void> {
try {
const healthStatus = await this.healthChecker.performHealthCheck();
const response = {
status: healthStatus.isHealthy ? 'healthy' : 'unhealthy',
timestamp: healthStatus.timestamp,
uptime: Math.floor(healthStatus.uptime / 1000),
checks: healthStatus.checks
};
const statusCode = healthStatus.isHealthy ? 200 : 503;
this.sendResponse(res, statusCode, response);
} catch (error) {
this.sendResponse(res, 500, {
status: 'error',
message: `Health check failed: ${error}`,
timestamp: new Date().toISOString()
});
}
}
/**
* 詳細なヘルスチェック
*/
private async handleDetailedHealthCheck(res: ServerResponse): Promise<void> {
try {
const reportJson = await this.healthChecker.generateHealthReport();
const report = JSON.parse(reportJson);
const statusCode = report.status === 'healthy' ? 200 : 503;
this.sendResponse(res, statusCode, report);
} catch (error) {
this.sendResponse(res, 500, {
status: 'error',
message: `Detailed health check failed: ${error}`,
timestamp: new Date().toISOString()
});
}
}
/**
* Prometheusメトリクス
*/
private async handleMetrics(res: ServerResponse): Promise<void> {
try {
const healthStatus = await this.healthChecker.performHealthCheck();
const metrics = [
`# HELP npm_dev_mcp_health Health status of the MCP server (1 = healthy, 0 = unhealthy)`,
`# TYPE npm_dev_mcp_health gauge`,
`npm_dev_mcp_health ${healthStatus.isHealthy ? 1 : 0}`,
'',
`# HELP npm_dev_mcp_uptime_seconds Uptime in seconds`,
`# TYPE npm_dev_mcp_uptime_seconds counter`,
`npm_dev_mcp_uptime_seconds ${Math.floor(healthStatus.uptime / 1000)}`,
'',
`# HELP npm_dev_mcp_memory_usage_bytes Memory usage in bytes`,
`# TYPE npm_dev_mcp_memory_usage_bytes gauge`,
`npm_dev_mcp_memory_usage_bytes{type="heap_used"} ${healthStatus.memoryUsage.heapUsed}`,
`npm_dev_mcp_memory_usage_bytes{type="rss"} ${healthStatus.memoryUsage.rss}`,
`npm_dev_mcp_memory_usage_bytes{type="external"} ${healthStatus.memoryUsage.external}`,
'',
`# HELP npm_dev_mcp_dev_server_status Status of the dev server (1 = running, 0 = stopped, -1 = error)`,
`# TYPE npm_dev_mcp_dev_server_status gauge`,
`npm_dev_mcp_dev_server_status ${
healthStatus.devServerStatus === 'running' ? 1 :
healthStatus.devServerStatus === 'stopped' ? 0 : -1
}`,
''
].join('\n');
res.setHeader('Content-Type', 'text/plain');
res.writeHead(200);
res.end(metrics);
} catch (error) {
this.sendResponse(res, 500, {
error: 'Failed to generate metrics',
message: String(error)
});
}
}
/**
* JSON レスポンスを送信
*/
private sendResponse(res: ServerResponse, statusCode: number, data: any): void {
res.setHeader('Content-Type', 'application/json');
res.writeHead(statusCode);
res.end(JSON.stringify(data, null, 2));
}
/**
* クリーンアップ
*/
cleanup(): void {
this.stop().catch(() => {});
HealthEndpoint.instance = null;
}
}