Logs & AccessLogs
Logs¶
Logs concern everything that happens to Traefik itself (startup, configuration, events, shutdown, and so on).
Configuration Example¶
log:
filePath: "/path/to/log-file.log"
format: json
level: INFO
[log]
filePath = "/path/to/log-file.log"
format = "json"
level = "INFO"
--log.filePath=/path/to/log-file.log
--log.format=json
--log.level=INFO
Configuration Options¶
The section below describe how to configure Traefik logs using the static configuration.
Field | Description | Default | Required |
---|---|---|---|
log.filePath |
By default, the logs are written to the standard output. You can configure a file path instead using the filePath option. |
- | No |
log.format |
Log format (common or json ).The fields displayed with the format common cannot be customized. |
"common" | No |
log.level |
Log level (TRACE , DEBUG , INFO , WARN , ERROR , FATAL , and PANIC ) |
ERROR | No |
log.noColor |
When using the format common , disables the colorized output. |
false | No |
log.maxSize |
Maximum size in megabytes of the log file before it gets rotated. | 100MB | No |
log.maxAge |
Maximum number of days to retain old log files based on the timestamp encoded in their filename. A day is defined as 24 hours and may not exactly correspond to calendar days due to daylight savings, leap seconds, etc. By default files are not removed based on their age. |
0 | No |
log.maxBackups |
Maximum number of old log files to retain. The default is to retain all old log files. |
0 | No |
log.compress |
Compress log files in gzip after rotation. | false | No |
AccessLogs¶
Configuration Example¶
accessLog:
# JSON format
format: json
# Filter on status codes, retry attempts and minimal duration
filters:
statusCodes:
- "200"
- "300-302"
retryAttempts: true
minDuration: "10ms"
fields:
# Keep all the fields by default
defaultMode: keep
names:
# Drop the Field ClientUserName
ClientUsername: drop
headers:
# Keep all the headers by default
defaultMode: keep
names:
# Redact the User-Agent header value
User-Agent: redact
# Drop the Authorization header value
Authorization: drop
[accessLog]
format = "json"
[accessLog.filters]
statusCodes = [ "200", "300-302" ]
retryAttempts = true
minDuration = "10ms"
[accessLog.fields]
defaultMode = "keep"
[accessLog.fields.names]
ClientUsername = "drop"
[accessLog.fields.headers]
defaultMode = "keep"
[accessLog.fields.headers.names]
User-Agent = "redact"
Authorization = "drop"
--accesslog=true
--accesslog.format=json
--accesslog.filters.statuscodes=200,300-302
--accesslog.filters.retryattempts
--accesslog.filters.minduration=10ms
--accesslog.fields.defaultmode=keep
--accesslog.fields.names.ClientUsername=drop
--accesslog.fields.headers.defaultmode=keep
--accesslog.fields.headers.names.User-Agent=redact
--accesslog.fields.headers.names.Authorization=drop
Configuration Options¶
The section below describes how to configure Traefik access logs using the static configuration.
Field | Description | Default | Required |
---|---|---|---|
accesslog.filePath |
By default, the access logs are written to the standard output. You can configure a file path instead using the filePath option. |
No | |
accesslog.format |
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. More information about CLF fields here. |
"common" | No |
accesslog.bufferingSize |
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. |
0 | No |
accesslog.addInternals |
Enables access logs for internal resources (e.g.: ping@internal ). |
false | No |
accesslog.filters.statusCodes |
Limit the access logs to requests with a status codes in the specified range. | false | No |
accesslog.filters.retryAttempts |
Keep the access logs when at least one retry has happened. | false | No |
accesslog.filters.minDuration |
Keep access logs when requests take longer than the specified duration (provided in seconds or as a valid duration format, see time.ParseDuration). | 0 | No |
accesslog.fields.defaultMode |
Mode to apply by default to the access logs fields (keep , redact or drop ). |
keep | No |
accesslog.fields.names |
Set the fields list to display in the access logs (format name:mode ).Available fields list here. |
- | No |
accesslog.headers.defaultMode |
Mode to apply by default to the access logs headers (keep , redact or drop ). |
drop | No |
accesslog.headers.names |
Set the headers list to display in the access logs (format name:mode ). |
- | No |
CLF format fields¶
Below the fields displayed with the CLF format:
<remote_IP_address> - <client_user_name_if_available> [<timestamp>]
"<request_method> <request_path> <request_protocol>" <HTTP_status> <content-length>
"<request_referrer>" "<request_user_agent>" <number_of_requests_received_since_Traefik_started>
"<Traefik_router_name>" "<Traefik_server_URL>" <request_duration_in_ms>ms
Available Fields¶
Field | Description |
---|---|
StartUTC |
The time at which request processing started. |
StartLocal |
The local time at which request processing started. |
Duration |
The total time taken (in nanoseconds) by processing the response, including the origin server's time but not the log writing time. |
RouterName |
The name of the Traefik router. |
ServiceName |
The name of the Traefik backend. |
ServiceURL |
The URL of the Traefik backend. |
ServiceAddr |
The IP:port of the Traefik backend (extracted from ServiceURL ). |
ClientAddr |
The remote address in its original form (usually IP:port). |
ClientHost |
The remote IP address from which the client request was received. |
ClientPort |
The remote TCP port from which the client request was received. |
ClientUsername |
The username provided in the URL, if present. |
RequestAddr |
The HTTP Host header (usually IP:port). This is treated as not a header by the Go API. |
RequestHost |
The HTTP Host server name (not including port). |
RequestPort |
The TCP port from the HTTP Host. |
RequestMethod |
The HTTP method. |
RequestPath |
The HTTP request URI, not including the scheme, host or port. |
RequestProtocol |
The version of HTTP requested. |
RequestScheme |
The HTTP scheme requested http or https . |
RequestLine |
The RequestMethod , + RequestPath and RequestProtocol . |
RequestContentSize |
The number of bytes in the request entity (a.k.a. body) sent by the client. |
OriginDuration |
The time taken (in nanoseconds) by the origin server ('upstream') to return its response. |
OriginContentSize |
The content length specified by the origin server, or 0 if unspecified. |
OriginStatus |
The HTTP status code returned by the origin server. If the request was handled by this Traefik instance (e.g. with a redirect), then this value will be absent (0). |
OriginStatusLine |
OriginStatus + Status code explanation |
DownstreamStatus |
The HTTP status code returned to the client. |
DownstreamStatusLine |
The DownstreamStatus and status code explanation. |
DownstreamContentSize |
The number of bytes in the response entity returned to the client. This is in addition to the "Content-Length" header, which may be present in the origin response. |
RequestCount |
The number of requests received since the Traefik instance started. |
GzipRatio |
The response body compression ratio achieved. |
Overhead |
The processing time overhead (in nanoseconds) caused by Traefik. |
RetryAttempts |
The amount of attempts the request was retried. |
TLSVersion |
The TLS version used by the connection (e.g. 1.2 ) (if connection is TLS). |
TLSCipher |
The TLS cipher used by the connection (e.g. TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA ) (if connection is TLS). |
TLSClientSubject |
The string representation of the TLS client certificate's Subject (e.g. CN=username,O=organization ). |
Log Rotation¶
Traefik 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.
Time Zones¶
Traefik will timestamp each log line in UTC time by default.
It is possible to configure the Traefik to timestamp in a specific timezone by ensuring the following configuration has been made in your environment:
- 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. - Specify the field
StartLocal
by dropping the field namedStartUTC
(available on the default Common Log Format (CLF) as well as JSON):accesslog.fields.names.StartUTC=drop
.
Example utilizing Docker Compose:
version: "3.7"
services:
traefik:
image: traefik:v3.2
environment:
- TZ=US/Alaska
command:
- --accesslog.fields.names.StartUTC=drop
- --providers.docker
ports:
- 80:80
volumes:
- /var/run/docker.sock:/var/run/docker.sock
Using Traefik OSS in Production?
If you are using Traefik at work, consider adding enterprise-grade API gateway capabilities or commercial support for Traefik OSS.
Adding API Gateway capabilities to Traefik OSS is fast and seamless. There's no rip and replace and all configurations remain intact. See it in action via this short video.