Add a status option to the service health check

docs/content/reference/dynamic-configuration/docker-labels.yml

@@ -153,6 +153,7 @@
 - "traefik.http.services.service01.loadbalancer.healthcheck.interval=foobar"
 - "traefik.http.services.service01.loadbalancer.healthcheck.path=foobar"
 - "traefik.http.services.service01.loadbalancer.healthcheck.method=foobar"
+- "traefik.http.services.service01.loadbalancer.healthcheck.status=42"
 - "traefik.http.services.service01.loadbalancer.healthcheck.port=42"
 - "traefik.http.services.service01.loadbalancer.healthcheck.scheme=foobar"
 - "traefik.http.services.service01.loadbalancer.healthcheck.mode=foobar"

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

@@ -56,6 +56,7 @@
           mode = "foobar"
           path = "foobar"
           method = "foobar"
+          status = 42
           port = 42
           interval = "42s"
           timeout = "42s"

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

@@ -61,6 +61,7 @@ http:
           mode: foobar
           path: foobar
           method: foobar
+          status: 42
           port: 42
           interval: 42s
           timeout: 42s

docs/content/reference/dynamic-configuration/kv-ref.md

@@ -220,6 +220,7 @@
 | `traefik/http/services/Service01/loadBalancer/healthCheck/path` | `foobar` |
 | `traefik/http/services/Service01/loadBalancer/healthCheck/port` | `42` |
 | `traefik/http/services/Service01/loadBalancer/healthCheck/scheme` | `foobar` |
+| `traefik/http/services/Service01/loadBalancer/healthCheck/status` | `42` |
 | `traefik/http/services/Service01/loadBalancer/healthCheck/timeout` | `42s` |
 | `traefik/http/services/Service01/loadBalancer/passHostHeader` | `true` |
 | `traefik/http/services/Service01/loadBalancer/responseForwarding/flushInterval` | `42s` |

docs/content/reference/dynamic-configuration/marathon-labels.json

@@ -153,6 +153,7 @@
 "traefik.http.services.service01.loadbalancer.healthcheck.interval": "42s",
 "traefik.http.services.service01.loadbalancer.healthcheck.path": "foobar",
 "traefik.http.services.service01.loadbalancer.healthcheck.method": "foobar",
+"traefik.http.services.service01.loadbalancer.healthcheck.status": "42",
 "traefik.http.services.service01.loadbalancer.healthcheck.port": "42",
 "traefik.http.services.service01.loadbalancer.healthcheck.scheme": "foobar",
 "traefik.http.services.service01.loadbalancer.healthcheck.mode": "foobar",

docs/content/routing/providers/consul-catalog.md

@@ -193,6 +193,14 @@ you'd add the tag `traefik.http.services.{name-of-your-choice}.loadbalancer.pass
     traefik.http.services.myservice.loadbalancer.healthcheck.method=foobar
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+    
+    See [health check](../services/index.md#health-check) for more information.
+    
+    ```yaml
+    traefik.http.services.myservice.loadbalancer.healthcheck.status=42
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
     
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/docker.md

@@ -347,6 +347,14 @@ you'd add the label `traefik.http.services.<name-of-your-choice>.loadbalancer.pa
     - "traefik.http.services.myservice.loadbalancer.healthcheck.method=foobar"
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+
+    See [health check](../services/index.md#health-check) for more information.
+
+    ```yaml
+    - "traefik.http.services.myservice.loadbalancer.healthcheck.status=42"
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
 
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/ecs.md

@@ -195,6 +195,14 @@ you'd add the label `traefik.http.services.{name-of-your-choice}.loadbalancer.pa
     traefik.http.services.myservice.loadbalancer.healthcheck.method=foobar
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+    
+    See [health check](../services/index.md#health-check) for more information.
+    
+    ```yaml
+    traefik.http.services.myservice.loadbalancer.healthcheck.status=42
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
     
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/kv.md

@@ -172,6 +172,14 @@ A Story of key & values
     |-------------------------------------------------------------------|----------|
     | `traefik/http/services/myservice/loadbalancer/healthcheck/method` | `foobar` |
 
+??? info "`traefik/http/services/<service_name>/loadbalancer/healthcheck/status`"
+
+    See [health check](../services/index.md#health-check) for more information.
+
+    | Key (Path)                                                        | Value |
+    |-------------------------------------------------------------------|-------|
+    | `traefik/http/services/myservice/loadbalancer/healthcheck/status` | `42`  |
+
 ??? info "`traefik/http/services/<service_name>/loadbalancer/healthcheck/port`"
 
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/marathon.md

@@ -222,6 +222,14 @@ For example, to change the passHostHeader behavior, you'd add the label `"traefi
     "traefik.http.services.myservice.loadbalancer.healthcheck.method": "foobar"
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+    
+    See [health check](../services/index.md#health-check) for more information.
+    
+    ```json
+    "traefik.http.services.myservice.loadbalancer.healthcheck.status": "42"
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
     
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/nomad.md

@@ -185,6 +185,14 @@ you'd add the tag `traefik.http.services.{name-of-your-choice}.loadbalancer.pass
     traefik.http.services.myservice.loadbalancer.healthcheck.path=/foo
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+
+    See [health check](../services/index.md#health-check) for more information.
+
+    ```yaml
+    traefik.http.services.myservice.loadbalancer.healthcheck.status=42
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
 
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/providers/rancher.md

@@ -228,6 +228,14 @@ you'd add the label `traefik.http.services.{name-of-your-choice}.loadbalancer.pa
     - "traefik.http.services.myservice.loadbalancer.healthcheck.method=foobar"
     ```
 
+??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.status`"
+    
+    See [health check](../services/index.md#health-check) for more information.
+    
+    ```yaml
+    - "traefik.http.services.myservice.loadbalancer.healthcheck.status=42"
+    ```
+
 ??? info "`traefik.http.services.<service_name>.loadbalancer.healthcheck.port`"
     
     See [health check](../services/index.md#health-check) for more information.

docs/content/routing/services/index.md

@@ -316,7 +316,7 @@ On subsequent requests, to keep the session alive with the same server, the clie
 #### Health Check
 
 Configure health check to remove unhealthy servers from the load balancing rotation.
-Traefik will consider your HTTP(s) servers healthy as long as they return status codes between `2XX` and `3XX` to the health check requests (carried out every `interval`).
+Traefik will consider HTTP(s) servers healthy as long as they return a status code to the health check request (carried out every `interval`) between `2XX` and `3XX`, or matching the configured status.
 For gRPC servers, Traefik will consider them healthy as long as they return `SERVING` to [gRPC health check v1](https://github.com/grpc/grpc/blob/master/doc/health-checking.md) requests.
 
 To propagate status changes (e.g. all servers of this service are down) upwards, HealthCheck must also be enabled on the parent(s) of this service.
@@ -333,6 +333,7 @@ Below are the available options for the health check mechanism:
 - `headers` (optional), defines custom headers to be sent to the health check endpoint.
 - `followRedirects` (default: true), defines whether redirects should be followed during the health check calls.
 - `method` (default: GET), defines the HTTP method that will be used while connecting to the endpoint.
+- `status` (optional), defines the expected HTTP status code of the response to the health check request.
 
 !!! info "Interval & Timeout Format"
 

pkg/config/dynamic/http_config.go

@@ -237,6 +237,7 @@ type ServerHealthCheck struct {
 	Mode            string            `json:"mode,omitempty" toml:"mode,omitempty" yaml:"mode,omitempty" export:"true"`
 	Path            string            `json:"path,omitempty" toml:"path,omitempty" yaml:"path,omitempty" export:"true"`
 	Method          string            `json:"method,omitempty" toml:"method,omitempty" yaml:"method,omitempty" export:"true"`
+	Status          int               `json:"status,omitempty" toml:"status,omitempty" yaml:"status,omitempty" export:"true"`
 	Port            int               `json:"port,omitempty" toml:"port,omitempty,omitzero" yaml:"port,omitempty" export:"true"`
 	Interval        ptypes.Duration   `json:"interval,omitempty" toml:"interval,omitempty" yaml:"interval,omitempty" export:"true"`
 	Timeout         ptypes.Duration   `json:"timeout,omitempty" toml:"timeout,omitempty" yaml:"timeout,omitempty" export:"true"`

pkg/config/label/label_test.go

@@ -151,6 +151,7 @@ func TestDecodeConfiguration(t *testing.T) {
 		"traefik.http.services.Service0.loadbalancer.healthcheck.interval":             "1s",
 		"traefik.http.services.Service0.loadbalancer.healthcheck.path":                 "foobar",
 		"traefik.http.services.Service0.loadbalancer.healthcheck.method":               "foobar",
+		"traefik.http.services.Service0.loadbalancer.healthcheck.status":               "401",
 		"traefik.http.services.Service0.loadbalancer.healthcheck.port":                 "42",
 		"traefik.http.services.Service0.loadbalancer.healthcheck.scheme":               "foobar",
 		"traefik.http.services.Service0.loadbalancer.healthcheck.mode":                 "foobar",
@@ -168,6 +169,7 @@ func TestDecodeConfiguration(t *testing.T) {
 		"traefik.http.services.Service1.loadbalancer.healthcheck.interval":             "1s",
 		"traefik.http.services.Service1.loadbalancer.healthcheck.path":                 "foobar",
 		"traefik.http.services.Service1.loadbalancer.healthcheck.method":               "foobar",
+		"traefik.http.services.Service1.loadbalancer.healthcheck.status":               "401",
 		"traefik.http.services.Service1.loadbalancer.healthcheck.port":                 "42",
 		"traefik.http.services.Service1.loadbalancer.healthcheck.scheme":               "foobar",
 		"traefik.http.services.Service1.loadbalancer.healthcheck.mode":                 "foobar",
@@ -655,6 +657,7 @@ func TestDecodeConfiguration(t *testing.T) {
 							Mode:     "foobar",
 							Path:     "foobar",
 							Method:   "foobar",
+							Status:   401,
 							Port:     42,
 							Interval: ptypes.Duration(time.Second),
 							Timeout:  ptypes.Duration(time.Second),
@@ -684,6 +687,7 @@ func TestDecodeConfiguration(t *testing.T) {
 							Mode:     "foobar",
 							Path:     "foobar",
 							Method:   "foobar",
+							Status:   401,
 							Port:     42,
 							Interval: ptypes.Duration(time.Second),
 							Timeout:  ptypes.Duration(time.Second),
@@ -1147,6 +1151,7 @@ func TestEncodeConfiguration(t *testing.T) {
 							Scheme:   "foobar",
 							Path:     "foobar",
 							Method:   "foobar",
+							Status:   401,
 							Port:     42,
 							Interval: ptypes.Duration(time.Second),
 							Timeout:  ptypes.Duration(time.Second),
@@ -1174,6 +1179,7 @@ func TestEncodeConfiguration(t *testing.T) {
 							Scheme:   "foobar",
 							Path:     "foobar",
 							Method:   "foobar",
+							Status:   401,
 							Port:     42,
 							Interval: ptypes.Duration(time.Second),
 							Timeout:  ptypes.Duration(time.Second),
@@ -1335,6 +1341,7 @@ func TestEncodeConfiguration(t *testing.T) {
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Interval":             "1000000000",
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Path":                 "foobar",
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Method":               "foobar",
+		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Status":               "401",
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Port":                 "42",
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Scheme":               "foobar",
 		"traefik.HTTP.Services.Service0.LoadBalancer.HealthCheck.Timeout":              "1000000000",
@@ -1351,6 +1358,7 @@ func TestEncodeConfiguration(t *testing.T) {
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Interval":             "1000000000",
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Path":                 "foobar",
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Method":               "foobar",
+		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Status":               "401",
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Port":                 "42",
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Scheme":               "foobar",
 		"traefik.HTTP.Services.Service1.LoadBalancer.HealthCheck.Timeout":              "1000000000",

pkg/healthcheck/healthcheck.go

@@ -173,10 +173,14 @@ func (shc *ServiceHealthChecker) checkHealthHTTP(ctx context.Context, target *ur
 
 	defer resp.Body.Close()
 
-	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusBadRequest {
+	if shc.config.Status == 0 && (resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusBadRequest) {
 		return fmt.Errorf("received error status code: %v", resp.StatusCode)
 	}
 
+	if shc.config.Status != 0 && shc.config.Status != resp.StatusCode {
+		return fmt.Errorf("received error status code: %v expected status code: %v", resp.StatusCode, shc.config.Status)
+	}
+
 	return nil
 }
 

pkg/healthcheck/healthcheck_test.go

@@ -249,6 +249,7 @@ func TestServiceHealthChecker_Launch(t *testing.T) {
 	testCases := []struct {
 		desc                  string
 		mode                  string
+		status                int
 		server                StartTestServer
 		expNumRemovedServers  int
 		expNumUpsertedServers int
@@ -263,6 +264,15 @@ func TestServiceHealthChecker_Launch(t *testing.T) {
 			expGaugeValue:         1,
 			targetStatus:          runtime.StatusUp,
 		},
+		{
+			desc:                  "healthy server staying healthy, with custom code status check",
+			server:                newHTTPServer(http.StatusNotFound),
+			status:                http.StatusNotFound,
+			expNumRemovedServers:  0,
+			expNumUpsertedServers: 1,
+			expGaugeValue:         1,
+			targetStatus:          runtime.StatusUp,
+		},
 		{
 			desc:                  "healthy server staying healthy (StatusNoContent)",
 			server:                newHTTPServer(http.StatusNoContent),
@@ -287,6 +297,15 @@ func TestServiceHealthChecker_Launch(t *testing.T) {
 			expGaugeValue:         0,
 			targetStatus:          runtime.StatusDown,
 		},
+		{
+			desc:                  "healthy server becoming sick, with custom code status check",
+			server:                newHTTPServer(http.StatusOK),
+			status:                http.StatusServiceUnavailable,
+			expNumRemovedServers:  1,
+			expNumUpsertedServers: 0,
+			expGaugeValue:         0,
+			targetStatus:          runtime.StatusDown,
+		},
 		{
 			desc:                  "healthy server toggling to sick and back to healthy",
 			server:                newHTTPServer(http.StatusServiceUnavailable, http.StatusOK),
@@ -348,6 +367,7 @@ func TestServiceHealthChecker_Launch(t *testing.T) {
 
 			config := &dynamic.ServerHealthCheck{
 				Mode:     test.mode,
+				Status:   test.status,
 				Path:     "/path",
 				Interval: ptypes.Duration(500 * time.Millisecond),
 				Timeout:  ptypes.Duration(499 * time.Millisecond),