`output` stage

The output stage is an action stage that takes data from the extracted map and changes the log line that will be sent to Loki.

Schema

output:
  # Name from extracted data to use for the log entry.
  source: <string>

Example

For the given pipeline:

- json:
    expressions:
      user: user
      message: message
- labels:
    user:
- output:
    source: message

And the given log line:

{"user": "alexis", "message": "hello, world!"}

Then the first stage will extract the following key-value pairs into the extracted map:

user: alexis
message: hello, world!

The second stage will then add user=alexis to the label set for the outgoing log line, and the final output stage will change the log line from the original JSON to hello, world!

Related Loki resources

Getting started with logging and Grafana Loki (Part 3 of 4)

Join this webinar to learn why correlating metrics and logs is critical across the development lifecycle, and how Loki helps reduce logging costs and operations overhead.