Add GenericCLF log format for access logs

docs/content/observability/access-logs.md

@@ -69,27 +69,43 @@ accessLog:
 
 _Optional, Default="common"_
 
-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.
+By default, logs are written using the Traefik Common Log Format (CLF).
+The available log formats are:
 
-!!! info "Common Log Format"
+- `common` - Traefik's extended CLF format (default)
+- `genericCLF` - Generic CLF format compatible with standard log analyzers
+- `json` - JSON format for structured logging
 
+If the given format is unsupported, the default (`common`) is used instead.
+
+!!! info "Traefik Common Log Format vs Generic CLF"
+
+    **Traefik Common Log Format (`common`):**
     ```html
     <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
     ```
+    
+    **Generic CLF Format (`genericCLF`):**
+    ```html
+    <remote_IP_address> - <client_user_name_if_available> [<timestamp>] "<request_method> <request_path> <request_protocol>" <HTTP_status> <content-length> "<request_referrer>" "<request_user_agent>"
+    ```
+    
+    The `genericCLF` format omits Traefik-specific fields (request count, router name, service URL, and duration) for better compatibility with standard CLF parsers.
 
 ```yaml tab="File (YAML)"
+# JSON format
 accessLog:
   format: "json"
 ```
 
 ```toml tab="File (TOML)"
+# JSON format
 [accessLog]
   format = "json"
 ```
 
 ```bash tab="CLI"
+# JSON format
 --accesslog.format=json
 ```
 

docs/content/observe/logs-and-access-logs.md

@@ -155,8 +155,9 @@ When the `observability` options are not defined on a router, it inherits the be
 
 Traefik Proxy supports the following log formats:
 
-- Common Log Format (CLF)
-- JSON
+- `common` - Traefik's extended CLF format (default)
+- `genericCLF` - Generic CLF format compatible with standard log analyzers
+- `json` - JSON format for structured logging
 
 ## Access Log Filters
 

docs/content/reference/install-configuration/configuration-options.md

@@ -18,7 +18,7 @@ THIS FILE MUST NOT BE EDITED BY HAND
 | accesslog.filters.minduration | Keep access logs when request took longer than the specified duration. | 0 |
 | accesslog.filters.retryattempts | Keep access logs when at least one retry happened. | false |
 | accesslog.filters.statuscodes | Keep access logs with status codes in the specified range. | |
-| accesslog.format | Access log format: json | common | common |
+| accesslog.format | Access log format: json, common, or genericCLF | common |
 | accesslog.otlp | Settings for OpenTelemetry. | false |
 | accesslog.otlp.grpc | gRPC configuration for the OpenTelemetry collector. | false |
 | accesslog.otlp.grpc.endpoint | Sets the gRPC endpoint (host:port) of the collector. | localhost:4317 |

docs/content/reference/install-configuration/observability/logs-and-accesslogs.md

@@ -195,7 +195,7 @@ The section below describes how to configure Traefik access logs using the stati
 | Field      | Description    | Default | Required |
 |:-----------|:--------------------------|:--------|:---------|
 | `accesslog.filePath` | By default, the access logs are written to the standard output.<br />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).<br />To write logs in JSON, use `json` in the `format` option.<br />If the given format is unsupported, the default (CLF) is used instead.<br />More information about CLF fields [here](#clf-format-fields). | "common" | No      |
+| `accesslog.format` | By default, logs are written using the Traefik Common Log Format (CLF).<br />Available formats: `common` (Traefik's extended CLF), `genericCLF` (standard CLF compatible with analyzers), or `json`.<br />If the given format is unsupported, the default (`common`) is used instead.<br />More information about CLF fields [here](#clf-format-fields). | "common" | No      |
 | `accesslog.bufferingSize` | To write the logs in an asynchronous fashion, specify a  `bufferingSize` option.<br />This option represents the number of log lines Traefik will keep in memory before writing them to the selected output.<br />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. | [ ]      | No      |