Source Code

1. Go to your cloned repo:

   cd /path/to/watchlog-agent
   vim integration.json
   
2. Locate the MongoDB config:

{ "service": "mongodb", "monitor": false, "host": "localhost", "port": "27017", "username": "", "password": "", "authDatabase": "admin", "tls": false }

3. Update `"monitor"` to `true` and set the credentials:
```diff
-  "monitor": false
+  "monitor": true

authDatabase is where the monitoring user is defined — usually admin. 4. Restart the agent:

pm2 restart watchlog-agent

Prerequisite

mongosh must be on PATH. The collection script uses the Promise-based shell API, which the legacy mongo shell does not provide — with only mongo available the agent falls back to the basic collector and the per-collection, index and slow-query tabs stay empty.

mongosh --version

Run the collector directly

Useful when you want the payload without waiting for the 60s tick:

node -e "
const list = require('./integration.json');
const cfg = list.find(i => i.service === 'mongodb');
require('./app/integrations/mongodb/index').collect(cfg, (err, res) => {
  if (err) return console.error('failed:', err.message);
  console.log('capabilities :', JSON.stringify(res.advanced.capabilities || {}));
  console.log('databases    :', (res.advanced.databases || []).length);
  console.log('collections  :', (res.advanced.collections || []).length);
  console.log('slow queries :', (res.advanced.slowQueries || []).length);
});
"

Running the tests

The MongoDB collector's parsers and shell-script builder are covered by the agent's test suite, which needs no live server:

npm test

Development notes

• The advanced collector sits at app/integrations/mongodb/index.js; the legacy one is app/integrations/mongo.js beside it. Require the advanced one by its full path — require('./app/integrations/mongodb/index').
• Both payloads come from one mongosh round-trip. The legacy event is emitted byte-for-byte as it always was, so existing dashboards keep working; the advanced event is additive.
• mongosh is Promise-based, so a rejection escapes a synchronous try/catch and kills the script. Every safe() callback in evalScript.js must await inside it.
• replSetGetStatus rejects normally on a standalone. That is not an error and must not be logged as one.
• Arguments go through execFile, never a shell, so a password containing a quote or ; cannot break out into the command line. Keep it that way.
• Storage and index traversal are throttled to 300s independently of the 60s tick. Walking every collection every minute is the main way a monitoring agent becomes the problem it was installed to detect.