fix: use exact service name match searching container labels

`findContainerByServiceName` incorrectly matched containers based on
service and router names when there were two services with similar
names, specifically when one service name was a prefix of the other.

Add a dot to the service and router needles and compare the labels with
HasPrefix() to ensure that only the exact matches get picked up.

docker.go

@@ -65,10 +65,10 @@ func findContainerByServiceName(dc client.APIClient, svcType string, svcName str
 			return types.ContainerJSON{}, errors.Wrapf(err, "failed to inspect container %s", c.ID)
 		}
 		// check labels
-		svcNeedle := fmt.Sprintf("traefik.%s.services.%s", svcType, svcName)
-		routerNeedle := fmt.Sprintf("traefik.%s.routers.%s", svcType, routerName)
+		svcNeedle := fmt.Sprintf("traefik.%s.services.%s.", svcType, svcName)
+		routerNeedle := fmt.Sprintf("traefik.%s.routers.%s.", svcType, routerName)
 		for k := range container.Config.Labels {
-			if strings.Contains(k, svcNeedle) || (routerName != "" && strings.Contains(k, routerNeedle)) {
+			if strings.HasPrefix(k, svcNeedle) || (routerName != "" && strings.HasPrefix(k, routerNeedle)) {
 				logrus.Debugf("found container '%s' (%s) for service '%s'", container.Name, container.ID, svcName)
 				return container, nil
 			}

docker_test.go

@@ -124,3 +124,14 @@ func Test_helloWorldNoCert(t *testing.T) {
 
 	// assert.Fail(t, "TODO: check for no cert")
 }
+
+func Test_samePrefix(t *testing.T) {
+	store := doTest(t, "prefix.yml")
+
+	// Two services `hello` and `hello-test`.
+	// The former's name is a prefix of the latter. Ensure the matching does not mix them up.
+	assertServiceIPs(t, store, []svc{
+		{"hello", "http", "http://192.168.100.100:5555"},
+		{"hello-test", "http", "http://192.168.100.100:5566"},
+	})
+}

fixtures/prefix.yml

@@ -0,0 +1,29 @@
+
+services:
+  hello:
+    image: helloworld
+    restart: unless-stopped
+    ports:
+      - 5555:5555
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.hello.rule=Host(`hello.local`)"
+      - "traefik.http.routers.hello.service=hello"
+      - "traefik.http.routers.hello.tls=true"
+      - "traefik.http.routers.hello.tls.certresolver=default"
+      - "traefik.http.services.hello.loadbalancer.server.scheme=http"
+      - "traefik.http.services.hello.loadbalancer.server.port=5555"
+
+  hello-test:
+    image: helloworld
+    restart: unless-stopped
+    ports:
+      - 5566:5566
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.hello-test.rule=Host(`hello-test.local`)"
+      - "traefik.http.routers.hello-test.service=hello-test"
+      - "traefik.http.routers.hello-test.tls=true"
+      - "traefik.http.routers.hello-test.tls.certresolver=default"
+      - "traefik.http.services.hello-test.loadbalancer.server.scheme=http"
+      - "traefik.http.services.hello-test.loadbalancer.server.port=5566"