Prometheus EC2 Service Discovery

prometheus-ec2-discovery generates target groups by querying the EC2 API and grouping your instances based on their tags. This is to be used in conjunction with Prometheus's custom service discovery feature.

Example

$ prometheus-ec2-discovery --port 9100 --tags=Type,Deployment
[
  {
    "targets": ["172.22.2.57:9100"],
    "labels": {"Deployment": "staging", "Type": "frontend"}
  },
  {
    "targets": ["172.22.1.81:9100", "172.22.1.149:9100", "172.22.2.142:9100"],
    "labels": {"Deployment": "production", "Type": "frontend"}
  },
  {
    "targets": ["172.22.1.121:9100"],
    "labels": {"Deployment": "staging", "Type": "backend"}
  },
  {
    "targets": ["172.22.2.245:9100", "172.22.2.248:9100"],
    "labels": {"Deployment": "production", "Type": "backend"}
  }
]

This generates to stdout all ec2 instances with either the Type or Deployment tag, and then labeled via the tag value. Note that the target ips are the PrivateIpAddress and that you must ensure prometheus is in the correct security groups to access the instances.

You can also filter on the tag value

$ prometheus-ec2-discovery --port 9100 --tags=Type=backend,Deployment
[
  {
    "targets": ["172.22.1.121:9100"],
    "labels": {"Deployment": "staging", "Type": "backend"}
  },
  {
    "targets": ["172.22.2.245:9100", "172.22.2.248:9100"],
    "labels": {"Deployment": "production", "Type": "backend"}
  }
]

Install

First install the binary

$ go get github.com/keegancsmith/prometheus-ec2-discovery

Then configure a [file based service discovery] 1 target group in your prometheus.yml config:

scrape_configs:
  - job_name: my_ec2_service

    file_sd_configs:
    - names: ['tgroups/*.json']

You can then setup a crontab job to update the target groups every minute:

* * * * * cd /path/to/prometheus/dir && . ./aws.inc && prometheus-ec2-discovery --tags=Name --dest=tgroups/ec2.json

In the example crontab command, aws.inc contains the AWS_* access keys environment variables.

All Tags

If you specify empty --tags=, then all tags are used.

Docker

$ docker run --rm -e AWS_SECRET_ACCESS_KEY -e AWS_ACCESS_KEY keegancsmith/prometheus-ec2-discovery