Logs

Reading What's Happening

By default, logs are written to stdout, in text format.

Configuration

General

Traefik logs concern everything that happens to Traefik itself (startup, configuration, events, shutdown, and so on).

filePath

By default, the logs are written to the standard output. You can configure a file path instead using the filePath option.

  1. # Writing Logs to a File
  2. [log]
  3.   filePath = "/path/to/traefik.log"
  1. # Writing Logs to a File
  2. log:
  3.   filePath: "/path/to/traefik.log"
  1. # Writing Logs to a File
  2. --log.filePath=/path/to/traefik.log

format

By default, the logs use a text format (common), but you can also ask for the json format in the format option. 

  1. # Writing Logs to a File, in JSON
  2. [log]
  3.   filePath = "/path/to/log-file.log"
  4.   format = "json"
  1. # Writing Logs to a File, in JSON
  2. log:
  3.   filePath: "/path/to/log-file.log"
  4.   format: json
  1. # Writing Logs to a File, in JSON
  2. --log.filePath=/path/to/traefik.log
  3. --log.format=json

level

By default, the level is set to ERROR. Alternative logging levels are DEBUG, PANIC, FATAL, ERROR, WARN, and INFO. 

  1. [log]
  2.   level = "DEBUG"
  1. log:
  2.   level: DEBUG
  1. --log.level=DEBUG

Log Rotation

Traefik will close and reopen its log files, assuming they're configured, on receipt of a USR1 signal. This allows the logs to be rotated and processed by an external program, such as logrotate.

Warning

This does not work on Windows due to the lack of USR signals.