api.md

Loki API

The Loki server has the following API endpoints (Note: Authentication is out of scope for this project):

• POST /api/prom/push

  For sending log entries, expects a snappy compressed proto in the HTTP Body:

  • ProtoBuffer definition
  • Golang client library

  Also accepts JSON formatted requests when the header Content-Type: application/json is sent. Example of the JSON format:

  {
    "streams": [
      {
        "labels": "{foo=\"bar\"}",
        "entries": [{ "ts": "2018-12-18T08:28:06.801064-04:00", "line": "baz" }]
      }
    ]
  }

• GET /api/prom/query

  For doing queries, accepts the following parameters in the query-string:

  • query: a logQL query (eg: {name=~"mysql.+"} or {name=~"mysql.+"} |= "error")
  • limit: max number of entries to return
  • start: the start time for the query, as a nanosecond Unix epoch (nanoseconds since 1970) or as RFC3339Nano (eg: "2006-01-02T15:04:05.999999999-07:00"). Default is always one hour ago.
  • end: the end time for the query, as a nanosecond Unix epoch (nanoseconds since 1970) or as RFC3339Nano (eg: "2006-01-02T15:04:05.999999999-07:00"). Default is current time.
  • direction: forward or backward, useful when specifying a limit. Default is backward.
  • regexp: a regex to filter the returned results

  Loki needs to query the index store in order to find log streams for particular labels and the store is spread out by time, so you need to specify the start and end labels accordingly. Querying a long time into the history will cause additional load to the index server and make the query slower.

  Responses looks like this:

  {
    "streams": [
      {
        "labels": "{instance=\"...\", job=\"...\", namespace=\"...\"}",
        "entries": [
          {
            "ts": "2018-06-27T05:20:28.699492635Z",
            "line": "..."
          },
          ...
        ]
      },
      ...
    ]
  }

• GET /api/prom/label

  For doing label name queries, accepts the following parameters in the query-string:

  • start: the start time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is always 6 hour ago.
  • end: the end time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is current time.

  Responses looks like this:

  {
    "values": [
      "instance",
      "job",
      ...
    ]
  }

• GET /api/prom/label/<name>/values

  For doing label values queries, accepts the following parameters in the query-string:

  • start: the start time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is always 6 hour ago.
  • end: the end time for the query, as a nanosecond Unix epoch (nanoseconds since 1970). Default is current time.

  Responses looks like this:

  {
    "values": [
      "default",
      "cortex-ops",
      ...
    ]
  }

Examples of using the API in a third-party client library

1. Take a look at this client, but be aware that the API is not stable yet (Golang).
2. Example on Python3