Configurable API & Dashboard base path

Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>

docs/content/reference/static-configuration/cli-ref.md

@@ -42,6 +42,9 @@ Access log format: json | common (Default: ```common```)
 `--api`:  
 Enable api/dashboard. (Default: ```false```)
 
+`--api.basepath`:  
+Defines the base path where the API and Dashboard will be exposed. (Default: ```/```)
+
 `--api.dashboard`:  
 Activate dashboard. (Default: ```true```)
 

docs/content/reference/static-configuration/env-ref.md

@@ -42,6 +42,9 @@ Access log format: json | common (Default: ```common```)
 `TRAEFIK_API`:  
 Enable api/dashboard. (Default: ```false```)
 
+`TRAEFIK_API_BASEPATH`:  
+Defines the base path where the API and Dashboard will be exposed. (Default: ```/```)
+
 `TRAEFIK_API_DASHBOARD`:  
 Activate dashboard. (Default: ```true```)
 

docs/content/reference/static-configuration/file.toml

@@ -294,6 +294,7 @@
       name1 = "foobar"
 
 [api]
+  basePath = "foobar"
   insecure = true
   dashboard = true
   debug = true

docs/content/reference/static-configuration/file.yaml

@@ -330,6 +330,7 @@ providers:
       name0: foobar
       name1: foobar
 api:
+  basePath: foobar
   insecure: true
   dashboard: true
   debug: true