added fix and test for handling istio header (#26)

* added test for handling istio header

* added current branch to push image

* updated host manager test

* removed push from branch

Author: shubhamrai1993

resolver/go.mod

@@ -12,6 +12,8 @@ require (
 	k8s.io/client-go v0.31.0
 )
 
+require github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+
 replace github.com/truefoundry/elasti/pkg v0.0.0 => ../pkg
 
 require (
@@ -39,6 +41,7 @@ require (
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.55.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/stretchr/testify v1.9.0
 	github.com/x448/float16 v0.8.4 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/oauth2 v0.21.0 // indirect

resolver/internal/hostManager/hostManager.go

@@ -51,6 +51,7 @@ func (hm *HostManager) GetHost(req *http.Request) (*messages.Host, error) {
 		}
 		targetService := utils.GetPrivateSerivceName(sourceService)
 		sourceHost := hm.removeTrailingWildcardIfNeeded(incomingHost)
+		sourceHost = hm.removeTrailingPathIfNeeded(sourceHost)
 		sourceHost = hm.addHTTPIfNeeded(sourceHost)
 		targetHost := hm.replaceServiceName(sourceHost, targetService)
 		targetHost = hm.addHTTPIfNeeded(targetHost)
@@ -149,6 +150,13 @@ func (hm *HostManager) removeTrailingWildcardIfNeeded(serviceURL string) string
 	return serviceURL
 }
 
+func (hm *HostManager) removeTrailingPathIfNeeded(serviceURL string) string {
+	if idx := strings.Index(serviceURL, "/"); idx != -1 {
+		return serviceURL[:idx]
+	}
+	return serviceURL
+}
+
 // replaceServiceName replaces the service name in the service URL
 func (hm *HostManager) replaceServiceName(serviceURL, newServiceName string) string {
 	parts := strings.Split(serviceURL, ".")

resolver/internal/hostManager/hostManager_test.go

@@ -0,0 +1,55 @@
+package hostManager
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/truefoundry/elasti/pkg/messages"
+	"go.uber.org/zap"
+)
+
+func TestGetHost(t *testing.T) {
+	logger, _ := zap.NewDevelopment()
+	hm := NewHostManager(logger, 10*time.Second, "X-Envoy-Decorator-Operation")
+
+	tests := []struct {
+		name          string
+		req           *http.Request
+		expectedHost  *messages.Host
+		expectedError bool
+	}{
+		{
+			name: "Host in header",
+			req: &http.Request{
+				Host: "target.com",
+				Header: http.Header{
+					"X-Envoy-Decorator-Operation": []string{"service.namespace.svc.cluster.local:8080/test/*"},
+				},
+			},
+			expectedHost: &messages.Host{
+				IncomingHost:   "service.namespace.svc.cluster.local:8080/test/*",
+				Namespace:      "namespace",
+				SourceService:  "service",
+				TargetService:  "elasti-service-pvt-9df6b026a8",
+				SourceHost:     "http://service.namespace.svc.cluster.local:8080",
+				TargetHost:     "http://elasti-service-pvt-9df6b026a8.namespace.svc.cluster.local:8080",
+				TrafficAllowed: true,
+			},
+			expectedError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			host, err := hm.GetHost(tt.req)
+			if tt.expectedError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+			assert.Equal(t, tt.expectedHost, host)
+		})
+	}
+}