pm2-slack-monitor/src/monitor.js

A CLI tool to monitor PM2 processes and send error logs to individual Slack channels via webhook.

const pm2 = require('pm2');
const slack = require('./slack');
const config = require('./config');

async function start() {
    const monitored = config.getProcesses();

    pm2.connect(err => {
        if (err) {
            console.error('❌ PM2 connection error', err);
            process.exit(2);
        }

        pm2.launchBus((err, bus) => {
            console.log('✅ Monitoring PM2 process events...');

            bus.on('process:event', data => {
                const { process, event } = data;
                const name = process.name;

                if (monitored.includes(name) && ['exit', 'error', 'exception'].includes(event)) {
                    const webhook = config.getWebhookForProcess(name);
                    if (!webhook) return;

                    // Fetch process logs
                    pm2.describe(name, (err, list) => {
                        if (err || !list || list.length === 0) {
                            return slack.send(`🚨 *${name}* had an event: *${event}* (but log fetch failed)`, webhook);
                        }

                        const info = list[0];
                        const lastLogs = ['exit', 'error', 'exception'].includes(event) ? info.pm2_env?.pm_err_log_path : info.pm2_env?.pm_out_log_path;
                        const fs = require('fs');
                        const tail = fs.readFileSync(lastLogs, 'utf8').split('\n').slice(-10).join('\n');
                        const msg = `🚨 *${name}* triggered *${event}*\n\`\`\`\n${tail}\n\`\`\``;
                        slack.send(msg, webhook);
                    });
                }
            });
        });
    });
}

module.exports = { start };