Prometheus MongoDB query exporter

MongoDB aggregation query exporter for Prometheus.

Features

Support for gauge and counter metrics
Multiple metrics for different db/collections
Pull and Push (Push is only supported for MongoDB >= 3.6)
Supports multiple MongoDB servers
Public API for Golang

Note that this is not designed to be a replacement for the MongoDB exporter to instrument MongoDB internals. This application exports custom MongoDB metrics in the prometheus format based on the queries (aggregations) you want.

Beta notice

This software is currently beta and the API/configuration may break without notice until a stable version is released.

Installation

Get Prometheus MongoDB aggregation query exporter, either as a binary or packaged as a Docker image.

Helm Chart

For kubernetes users there is an official helm chart for the MongoDB query exporter.

Usage

$ mongodb_query_exporter

Use the -help flag to get help information.

If you use MongoDB Authorization, best practices is to create a dedicated readonly user:

Create a user with 'read' on your database, like the following (replace username/password/db!):

db.getSiblingDB("admin").createUser({
    user: "mongodb_query_exporter",
    pwd: "secret",
    roles: [
        { role: "read", db: "mydb" }
    ]
})

Set environment variable MONGODB_URI before starting the exporter:

export MDBEXPORTER_MONGODB_URI=mongodb://mongodb_query_exporter:secret@localhost:27017

If you use x.509 Certificates to Authenticate Clients, pass in username and authMechanism via connection options to the MongoDB uri. Eg:

mongodb://CN=myName,OU=myOrgUnit,O=myOrg,L=myLocality,ST=myState,C=myCountry@localhost:27017/?authMechanism=MONGODB-X509

Access metrics

The metrics are exposed at /metrics.

curl localhost:9412/metrics

Configuration

The exporter is looking for a configuration in ~/config.yaml and /etc/mongodb-query-exporter/config.yaml or if set the path from the env MDBEXPORTER_CONFIG.

You may also use env variables to configure the exporter:

Env variable	Description
MDBEXPORTER_CONFIG	Custom path for the configuration
MDBEXPORTER_MONGODB_URI	The MongoDB connection URI
MDBEXPORTER_MONGODB_QUERY_TIMEOUT	Timeout until a MongoDB operations gets aborted
MDBEXPORTER_LOG_LEVEL	Log level
MDBEXPORTER_LOG_ENCODING	Log format
MDBEXPORTER_BIND	Bind address for the HTTP server

Note if you have multiple collectors you can inject an env variable for the MongoDB connection URI like:

MDBEXPORTER_COLLECTOR_0_MONGODB_URI=mongodb://srv1:27017
MDBEXPORTER_COLLECTOR_1_MONGODB_URI=mongodb://srv2:27017
...

Format v2.0

The config format v2.0 is not supported in any version before v1.0.0-beta5. Please use v1.0 or upgrade to the latest version otherwise.

Example: config.yml

version: 2.0
bind: 0.0.0.0:9412
log:
  encoding: json
  level: info
  development: false
  disableCaller: false
collectors:
- mongodb:
    uri: mongodb://localhost:27017
    queryTimeout: 10
    maxConnection: 3
    defaultInterval: 5
  metrics:
  - name: myapp_example_simplevalue_total
    type: gauge
    help: 'Simple gauge metric'
    value: total
    labels: []
    mode: pull
    interval: 10
    constLabels: []
    database: mydb
    collection: objects  
    pipeline: |
      [
        {"$count":"total"}
      ]  
  - name: myapp_example_processes_total
    type: gauge
    help: 'The total number of processes in a job queue'
    value: total
    mode: push
    labels: [type,status]
    constLabels: []
    database: mydb
    collection: queue
    pipeline: |
      [
        {"$group": {
          "_id":{"status":"$status","name":"$class"},
          "total":{"$sum":1}
        }},
        {"$project":{
          "_id":0,
          "type":"$_id.name",
          "total":"$total",
          "status": {
            "$switch": {
                "branches": [
                   { "case": { "$eq": ["$_id.status", 0] }, "then": "waiting" },
                   { "case": { "$eq": ["$_id.status", 1] }, "then": "postponed" },
                   { "case": { "$eq": ["$_id.status", 2] }, "then": "processing" },
                   { "case": { "$eq": ["$_id.status", 3] }, "then": "done" },
                   { "case": { "$eq": ["$_id.status", 4] }, "then": "failed" },
                   { "case": { "$eq": ["$_id.status", 5] }, "then": "canceled" },
                   { "case": { "$eq": ["$_id.status", 6] }, "then": "timeout" }
                ],
                "default": "unknown"
            }}
        }}
      ]

Format v1.0

The config version v1.0 is the predescer of v2.0 and does not have support for multiple MongoDB servers nor is it possible to customize logging. When possible use v2.0 however v1.0 support won't be dropped.