Different Prometheus scrape URL for every target

Question

Every instance of my application has a different URL. How can I configure prometheus.yml so that it takes path of a target along with the host name?

scrape_configs:
- job_name:       'example-random'

# Override the global default and scrape targets from this job every 5 seconds.
scrape_interval: 5s

static_configs:
  - targets: ['localhost:8090','localhost:8080']
    labels:
      group: 'dummy'

Answer 1

You currently can't configure the metrics_path per target within a job but you can create separate jobs for each of your targets so you can define metrics_path per target.

Your config file would look something like this:

scrape_configs:
- job_name:       'example-target-1'
  scrape_interval: 5s
  metrics_path: /target-1-path-to-metrics
  static_configs:
    - targets: ['localhost:8090']
      labels:
        group: 'dummy'

- job_name:       'example-target-2'
  scrape_interval: 5s
  metrics_path: /totally-different-path-for-target-2
  static_configs:
    - targets: ['localhost:8080']
      labels:
        group: 'dummy-2'

Answer 2

I achieved this by using file_sd_config option. All targets are described in separate file(s), which can be either in YML or JSON format.

prometheus.yml:

scrape_configs:
  - job_name: 'dummy'  # This will be overridden in targets.yml
    file_sd_configs:
      - files:
        - targets.yml

targets.yml:

- targets: ['host1:9999']
  labels:
    job: my_job
    __metrics_path__: /path1

- targets: ['host2:9999']
  labels:
    job: my_job  # can belong to the same job
    __metrics_path__: /path2

Answer 3

I believe you need to do some relabelling of the __metrics_path__ label set to include the varying paths of your applications.

The Prometheus configuration docs will prove useful to you here and this article should help you understand relabelling a little better.