Add custom ping http code when Traefik is terminating

docs/content/operations/ping.md

@@ -81,3 +81,28 @@ ping:
 ```bash tab="CLI"
 --ping.manualrouting=true
 ```
+
+### `terminatingStatusCode`
+
+_Optional, Default=503_
+
+During the period in which Traefik is gracefully shutting down, the ping handler
+returns a 503 status code by default. If Traefik is behind e.g. a load-balancer
+doing health checks (such as the Kubernetes LivenessProbe), another code might
+be expected as the signal for graceful termination. In which case, the
+terminatingStatusCode can be used to set the code returned by the ping
+handler during termination.
+
+```toml tab="File (TOML)"
+[ping]
+  terminatingStatusCode = 204
+```
+
+```yaml tab="File (YAML)"
+ping:
+  terminatingStatusCode: 204
+```
+
+```bash tab="CLI"
+--ping.terminatingStatusCode=204
+```

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

@@ -279,6 +279,9 @@ EntryPoint (Default: ```traefik```)
 `--ping.manualrouting`:  
 Manual routing (Default: ```false```)
 
+`--ping.terminatingstatuscode`:  
+Terminating status code (Default: ```503```)
+
 `--providers.consul`:  
 Enable Consul backend with default settings. (Default: ```false```)
 

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

@@ -279,6 +279,9 @@ EntryPoint (Default: ```traefik```)
 `TRAEFIK_PING_MANUALROUTING`:  
 Manual routing (Default: ```false```)
 
+`TRAEFIK_PING_TERMINATINGSTATUSCODE`:  
+Terminating status code (Default: ```503```)
+
 `TRAEFIK_PROVIDERS_CONSUL`:  
 Enable Consul backend with default settings. (Default: ```false```)