prometheus_scrape source's query doesn't add the [] to mapping list

[valleedelisle]

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Problem

Result:

2024-12-18T03:55:00.342027Z DEBUG source{component_kind="source" component_id=src-metrics-prod-proxy component_type=prometheus_scrape}:http: vector::internal_events::http_client: Sending HTTP request. uri=https://myprometheus/federate?match=%7Bjob%3D%something%22%7D method=GET version=HTTP/1.1 headers={"accept": "text/plain", "user-agent": "Vector/0.43.1 (x86_64-unknown-linux-musl e30bf1f 2024-12-10 16:14:47.175528383)", "accept-encoding": "identity"} body=[empty]

Configuration

Sample config:


      src-metrics-prod-proxy:
        endpoints:
        - "https://myprometheus/federate"
        honor_labels: true
        scrape_interval_secs: 60
        scrape_timeout_secs: 45
        query:
          match:
            - '{job="something"}'
        tls:
          verify_certificate: false
          verify_hostname: false
        type: prometheus_scrape

Version

vector 0.43.1 (x86_64-unknown-linux-musl e30bf1f 2024-12-10 16:14:47.175528383)

Debug Output

No response

Example Data

No response

Additional Context

No response

References

No response

[jszwedko]

HI @valleedelisle !

I think I'm missing the issue here. Could you describe the expected behavior?

[valleedelisle]

Sorry, I should have clarified this.

Prometheus is expecting a url like this:
https://myprometheus/federate?match[]=%7Bjob%3D%something%22%7D

As opposed to this:
https://myprometheus/federate?match=%7Bjob%3D%something%22%7D

[jszwedko]

Ah I see. It's curious that this issue hasn't been reported before. That match feature has been there for quite a while 🤔

[sainad2222]

I tried by modifying your source config to include [] after match, something like this and it's working after that

Sample config:


      src-metrics-prod-proxy:
        endpoints:
        - "https://myprometheus/federate"
        honor_labels: true
        scrape_interval_secs: 60
        scrape_timeout_secs: 45
        query:
          match[]:
            - '{job="something"}'
        tls:
          verify_certificate: false
          verify_hostname: false
        type: prometheus_scrape

But if we want to make it easier, I created a PR to replace match key with match[] at source while building url