callmedba / mongo_shell_exporter

Zero-setup MongoDB exporter for Prometheus

MongoDB Shell Exporter

Zero-dependency Prometheus exporter for MongoDB.

Features:

• No dependencies
• Collection & Index level metric export
• Replica Set support

Planned features:

• Sharded Cluster support
• Select metrics to be exported
• Selection of databases and collection to be exported
• More metrics!

Supported MongoDB Versions:

• 4.2.6+

It might work with other versions

Usage

Just download mongo_exporter.js from Releases and run it with mongo shell.

1. curl -L https://github.com/db-ai/mongo_shell_exporter/releases/latest/download/mongo_exporter.js > mongo_exporter.js
2. mongo --quiet mongo_exporter.js

You can pass other options, like authentication, port, host or connection uri as usual.

If you are exporting data from Replica Set, most appropriate strategy is to deploy Script Exporter on each node. Use localhost connection, to ensure that your are making direct connection.

Access control

If you use Authentication, then you have to add an user account:

    db.getSiblingDB("admin").createUser({
      user: "mongodb_exporter",
      pwd: passwordPrompt(),
      roles: [
          { role: "clusterMonitor", db: "admin" },
          { role: "read", db: "local" }
      ]
    })

and then you can run exporter with new credentials:

  mongo --quiet mongo_exporter.js --username mongodb_exporter --password

Exporiting to Prometheus

You can export metrics to prometheus using one of the following methods:

Script Exporter (Recommended)

Best way to export metrics from the mongo_shell_exporter is to install script_exporter, and configure export task:

scripts:
  - name: mongo_shell_exporter
    script: mongo --quiet /path/to/mongo_exporter.js

Don't forget to enable authentication for your exporter.

Node Exporter

You can use [Textfile Collector] to periodically export metrics using scheduler.

Configure your scheduller to pereodically dump metrics to --collector.textfile.directory, for example:

mongo --quiet /path/to/mongo_exporter.js > /path/to/directory/mongo_shell_exporter.prom.$$
mv /path/to/directory/mongo_shell_exporter.prom.$$ /path/to/directory/mongo_shell_exporter.prom

Note: this method doesn't follow Prometheus recommendations. Read more here

nc-based http server

You can find kind of http server example in examples folder. It uses nc to listen on port 9999 and return metrics each time someone is connected.

There is multiple caveats with this method as well:

1. No authentication, authorization or access control of any kind
2. nc implementations can differ and it might be tricky to properly configure it