Add a warning when health checks are overridden

Fixes #31

Signed-off-by: Nick Young <ynick@vmware.com>

internal/translator/testdata/health-checks-multiple/errors.txt

@@ -0,0 +1 @@
+A healthcheck of /healthy2 could not be applied, HTTPProxy only supports a single healthcheck across all services. /healthy is already applied.

internal/translator/testdata/health-checks-multiple/input.yaml

@@ -0,0 +1,28 @@
+---
+apiVersion: contour.heptio.com/v1beta1
+kind: IngressRoute
+metadata:
+  name: health-check
+  namespace: default
+spec:
+  virtualhost:
+    fqdn: health.bar.com
+  routes:
+    - match: /
+      services:
+        - name: s1-health
+          port: 80
+          healthCheck:
+            path: /healthy
+            intervalSeconds: 5
+            timeoutSeconds: 2
+            unhealthyThresholdCount: 3
+            healthyThresholdCount: 5
+        - name: s2-health
+          port: 80
+          healthCheck:
+            path: /healthy2
+            intervalSeconds: 5
+            timeoutSeconds: 2
+            unhealthyThresholdCount: 3
+            healthyThresholdCount: 5

internal/translator/testdata/health-checks-multiple/output.yaml

@@ -0,0 +1,24 @@
+---
+apiVersion: projectcontour.io/v1
+kind: HTTPProxy
+metadata:
+  name: health-check
+  namespace: default
+spec:
+  routes:
+  - conditions:
+    - prefix: /
+    healthCheckPolicy:
+      healthyThresholdCount: 5
+      intervalSeconds: 0
+      path: /healthy
+      timeoutSeconds: 2
+      unhealthyThresholdCount: 3
+    services:
+    - name: s1-health
+      port: 80
+    - name: s2-health
+      port: 80
+  virtualhost:
+    fqdn: health.bar.com
+status: {}

internal/translator/translate.go

@@ -119,6 +119,7 @@ func translateRoute(irRoute irv1beta1.Route, routeLCP string) (hpv1.Route, []str
 	}
 
 	var seenLBStrategy string
+	var seenHealthCheckPolicy string
 	for _, irService := range irRoute.Services {
 
 		service := hpv1.Service{
@@ -129,9 +130,9 @@ func translateRoute(irRoute irv1beta1.Route, routeLCP string) (hpv1.Route, []str
 
 		if irService.Strategy != "" {
 			if seenLBStrategy == "" {
-				seenLBStrategy = irService.Strategy
 				// Copy the first strategy we encounter into the HP loadbalancerpolicy
 				// and save that we've seen that one.
+				seenLBStrategy = irService.Strategy
 				route.LoadBalancerPolicy = &hpv1.LoadBalancerPolicy{
 					Strategy: irService.Strategy,
 				}
@@ -143,12 +144,21 @@ func translateRoute(irRoute irv1beta1.Route, routeLCP string) (hpv1.Route, []str
 
 		}
 		if irService.HealthCheck != nil {
-			route.HealthCheckPolicy = &hpv1.HTTPHealthCheckPolicy{
-				Path:                    irService.HealthCheck.Path,
-				Host:                    irService.HealthCheck.Host,
-				TimeoutSeconds:          irService.HealthCheck.TimeoutSeconds,
-				UnhealthyThresholdCount: irService.HealthCheck.UnhealthyThresholdCount,
-				HealthyThresholdCount:   irService.HealthCheck.HealthyThresholdCount,
+			if seenHealthCheckPolicy == "" {
+				// Copy the first strategy we encounter into the HP loadbalancerpolicy
+				// and save that we've seen that one.
+				seenHealthCheckPolicy = irService.HealthCheck.Host + irService.HealthCheck.Path
+				route.HealthCheckPolicy = &hpv1.HTTPHealthCheckPolicy{
+					Path:                    irService.HealthCheck.Path,
+					Host:                    irService.HealthCheck.Host,
+					TimeoutSeconds:          irService.HealthCheck.TimeoutSeconds,
+					UnhealthyThresholdCount: irService.HealthCheck.UnhealthyThresholdCount,
+					HealthyThresholdCount:   irService.HealthCheck.HealthyThresholdCount,
+				}
+			} else {
+				if seenHealthCheckPolicy != irService.HealthCheck.Host+irService.HealthCheck.Path {
+					warnings = append(warnings, fmt.Sprintf("A healthcheck of %s%s could not be applied, HTTPProxy only supports a single healthcheck across all services. %s is already applied.", irService.HealthCheck.Host, irService.HealthCheck.Path, seenHealthCheckPolicy))
+				}
 			}
 		}
 		route.Services = append(route.Services, service)