Access Logs

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

To enable the access logs:

File (YAML)

File (TOML)

[accessLog]

CLI

--accesslog=true

By default access logs are written to the standard output. To write the logs into a log file, use the filePath option.

File (YAML)

accessLog:
  filePath: "/path/to/access.log"

File (TOML)

[accessLog]
  filePath = "/path/to/access.log"

CLI

By default, logs are written using the Common Log Format (CLF). To write logs in JSON, use json in the format option. If the given format is unsupported, the default (CLF) is used instead.

<remote_IP_address> - <client_user_name_if_available> [<timestamp>] "<request_method> <request_path> <request_protocol>" <origin_server_HTTP_status> <origin_server_content_size> "<request_referrer>" "<request_user_agent>" <number_of_requests_received_since_Traefik_started> "<Traefik_router_name>" "<Traefik_server_URL>" <request_duration_in_ms>ms

To write the logs in an asynchronous fashion, specify a bufferingSize option. This option represents the number of log lines Traefik will keep in memory before writing them to the selected output. In some cases, this option can greatly help performances.

File (YAML)

# Configuring a buffer of 100 lines
accessLog:
  filePath: "/path/to/access.log"
  bufferingSize: 100

File (TOML)

# Configuring a buffer of 100 lines
[accessLog]
  filePath = "/path/to/access.log"
  bufferingSize = 100

CLI

# Configuring a buffer of 100 lines
--accesslog.filepath=/path/to/access.log
--accesslog.bufferingsize=100

To filter logs, you can specify a set of filters which are logically “OR-connected”. Thus, specifying multiple filters will keep more access logs than specifying only one.

The available filters are:

• statusCodes, to limit the access logs to requests with a status codes in the specified range
• retryAttempts, to keep the access logs when at least one retry has happened
• minDuration, to keep access logs when requests take longer than the specified duration (provided in seconds or as a valid duration format, see time.ParseDuration)

File (YAML)

File (TOML)

# Configuring Multiple Filters
  filePath = "/path/to/access.log"
  format = "json"
  [accessLog.filters]
    statusCodes = ["200", "300-302"]
    retryAttempts = true
    minDuration = "10ms"

CLI

# Configuring Multiple Filters
--accesslog.filepath=/path/to/access.log
--accesslog.format=json
--accesslog.filters.statuscodes=200,300-302
--accesslog.filters.retryattempts
--accesslog.filters.minduration=10ms

You can decide to limit the logged fields/headers to a given list with the fields.names and fields.headers options.

• to keep the value
• drop to drop the value
• redact to replace the value with “redacted”

The defaultMode for fields.headers is drop.

[accessLog.fields] defaultMode = “keep”

File (YAML)

# Limiting the Logs to Specific Fields
accessLog:
  filePath: "/path/to/access.log"
  format: json
  fields:
    defaultMode: keep
    names:
      ClientUsername: drop
    headers:
      defaultMode: keep
      names:
          User-Agent: redact
          Authorization: drop
          Content-Type: keep

File (TOML)

[accessLog]
  filePath = "/path/to/access.log"
  format = "json"
    [accessLog.fields.names]
      "ClientUsername" = "drop"
    [accessLog.fields.headers]
      defaultMode = "keep"
      [accessLog.fields.headers.names]
        "User-Agent" = "redact"
        "Authorization" = "drop"
        "Content-Type" = "keep"

CLI

Available Fields

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.

Traefik will timestamp each log line in UTC time by default.

1. Provide time zone data to /etc/localtime or /usr/share/zoneinfo (based on your distribution) or set the environment variable TZ to the desired timezone
2. Specify the field StartLocal by dropping the field named StartUTC (available on the default Common Log Format (CLF) as well as JSON)

Example utilizing Docker Compose:

version: "3.7"
services:
  traefik:
    image: traefik:v2.2
    environment:
      - TZ=US/Alaska
    command:
      - --accesslog.fields.names.StartUTC=drop
      - --providers.docker
    ports:
      - 80:80
    volumes: