Logging

Logging can either be as plain messages or as JSON with one line per log message.

Plain log messages (default)

The format of plain messages is:

[<date>] [<severity>] [<context>] <message>

Example plain log message:

[2022/02/22 01:02:03.456] [i] [MessageService] An example log message.

The placeholder values are:

• date: YYYY/MM/DD hh:mm:ss.SSS
• severity:
  • e: error
  • w: warning
  • i: information / notice
  • v: verbose
  • d: debug
• context: a service name consisting of [A-Za-z0-9].
• message: a human readable text message.
  • May contain a JSON object at the end if there’s additional information available that’s not included in the message itself.

JSON format

Logs one line per message as an object containing:

• timestamp: unix timestamp of the message, including milliseconds.
• level: one of error, warn, info, verbose, debug.
• context: a service name consisting of [A-Za-z0-9].
• message: a human readable text message.
• …: any additional information that’s not included in the message, e.g. stack if an exception was thrown.