Handle Headless Services when no ports are present

pkg/transformer/kubernetes/k8sutils.go

@@ -258,7 +258,7 @@ func convertToVersion(obj runtime.Object, groupVersion unversioned.GroupVersion)
 // PortsExist checks if service has ports defined
 func (k *Kubernetes) PortsExist(name string, service kobject.ServiceConfig) bool {
 	if len(service.Port) == 0 {
-		logrus.Warningf("[%s] Service cannot be created because of missing port.", name)
+		logrus.Warningf("[%s] No ports defined, we will create a Headless service.", name)
 		return false
 	}
 	return true
@@ -282,6 +282,27 @@ func (k *Kubernetes) CreateService(name string, service kobject.ServiceConfig, o
 	return svc
 }
 
+// CreateHeadlessService creates a k8s headless service
+func (k *Kubernetes) CreateHeadlessService(name string, service kobject.ServiceConfig, objects []runtime.Object) *api.Service {
+	svc := k.InitSvc(name, service)
+
+	servicePorts := []api.ServicePort{}
+	// Configure a dummy port: https://github.com/kubernetes/kubernetes/issues/32766.
+	servicePorts = append(servicePorts, api.ServicePort{
+		Name: "headless",
+		Port: 55555,
+	})
+
+	svc.Spec.Ports = servicePorts
+	svc.Spec.ClusterIP = "None"
+
+	// Configure annotations
+	annotations := transformer.ConfigAnnotations(service)
+	svc.ObjectMeta.Annotations = annotations
+
+	return svc
+}
+
 // UpdateKubernetesObjects loads configurations to k8s objects
 func (k *Kubernetes) UpdateKubernetesObjects(name string, service kobject.ServiceConfig, objects *[]runtime.Object) {
 	// Configure the environment variables.

pkg/transformer/kubernetes/kubernetes.go

@@ -477,6 +477,9 @@ func (k *Kubernetes) Transform(komposeObject kobject.KomposeObject, opt kobject.
 				if service.ExposeService != "" {
 					objects = append(objects, k.initIngress(name, service, svc.Spec.Ports[0].Port))
 				}
+			} else {
+				svc := k.CreateHeadlessService(name, service, objects)
+				objects = append(objects, svc)
 			}
 		}
 

script/test/cmd/tests.sh

@@ -23,7 +23,8 @@ convert::expect_failure "kompose -f $KOMPOSE_ROOT/script/test/fixtures/etherpad/
 
 # commenting this test case out until image handling is fixed
 convert::expect_failure "kompose -f $KOMPOSE_ROOT/script/test/fixtures/etherpad/docker-compose-no-image.yml convert --stdout"
-convert::expect_warning "kompose -f $KOMPOSE_ROOT/script/test/fixtures/etherpad/docker-compose-no-ports.yml convert --stdout" "Service cannot be created because of missing port."
+convert::expect_warning "kompose -f $KOMPOSE_ROOT/script/test/fixtures/etherpad/docker-compose-no-ports.yml convert --stdout" "No ports defined, we will create a Headless service."
+
 export $(cat $KOMPOSE_ROOT/script/test/fixtures/etherpad/envs)
 # kubernetes test
 convert::expect_success_and_warning "kompose -f $KOMPOSE_ROOT/script/test/fixtures/etherpad/docker-compose.yml convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/etherpad/output-k8s.json" "Unsupported depends_on key - ignoring"
@@ -51,9 +52,9 @@ convert::expect_success_warning "kompose --provider=openshift -f $KOMPOSE_ROOT/s
 ######
 # Tests related to docker-compose file in /script/test/fixtures/entrypoint-command
 # kubernetes test
-convert::expect_success_and_warning "kompose -f $KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/docker-compose.yml convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/output-k8s.json" "Service cannot be created because of missing port."
+convert::expect_success_and_warning "kompose -f $KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/docker-compose.yml convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/output-k8s.json" "No ports defined, we will create a Headless service."
 # openshift test
-convert::expect_success_and_warning "kompose --provider=openshift -f $KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/docker-compose.yml convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/output-os.json" "Service cannot be created because of missing port."
+convert::expect_success_and_warning "kompose --provider=openshift -f $KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/docker-compose.yml convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/entrypoint-command/output-os.json" "No ports defined, we will create a Headless service."
 
 
 ######
@@ -105,7 +106,7 @@ convert::expect_success_and_warning "kompose --provider=openshift -f $KOMPOSE_RO
 
 ######
 # Test related to kompose --bundle convert to ensure that DSB bundles are converted properly
-convert::expect_success_and_warning "kompose --bundle $KOMPOSE_ROOT/script/test/fixtures/bundles/dsb/docker-voting-bundle.dsb convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/bundles/dsb/output-k8s.json" "Service cannot be created because of missing port."
+convert::expect_success_and_warning "kompose --bundle $KOMPOSE_ROOT/script/test/fixtures/bundles/dsb/docker-voting-bundle.dsb convert --stdout -j" "$KOMPOSE_ROOT/script/test/fixtures/bundles/dsb/output-k8s.json" "No ports defined, we will create a Headless service."
 
 ######
 # Test related to restart options in docker-compose

script/test/fixtures/bundles/dsb/output-k8s.json

@@ -3,6 +3,33 @@
   "apiVersion": "v1",
   "metadata": {},
   "items": [
+    {
+      "kind": "Service",
+      "apiVersion": "v1",
+      "metadata": {
+        "name": "worker",
+        "creationTimestamp": null,
+        "labels": {
+          "service": "worker"
+        }
+      },
+      "spec": {
+        "ports": [
+          {
+            "name": "headless",
+            "port": 55555,
+            "targetPort": 0
+          }
+        ],
+        "selector": {
+          "service": "worker"
+        },
+        "clusterIP": "None"
+      },
+      "status": {
+        "loadBalancer": {}
+      }
+    },
     {
       "kind": "Service",
       "apiVersion": "v1",
@@ -117,6 +144,37 @@
         "loadBalancer": {}
       }
     },
+    {
+      "kind": "Deployment",
+      "apiVersion": "extensions/v1beta1",
+      "metadata": {
+        "name": "worker",
+        "creationTimestamp": null
+      },
+      "spec": {
+        "replicas": 1,
+        "template": {
+          "metadata": {
+            "creationTimestamp": null,
+            "labels": {
+              "service": "worker"
+            }
+          },
+          "spec": {
+            "containers": [
+              {
+                "name": "worker",
+                "image": "docker/example-voting-app-worker",
+                "resources": {}
+              }
+            ],
+            "restartPolicy": "Always"
+          }
+        },
+        "strategy": {}
+      },
+      "status": {}
+    },
     {
       "kind": "Deployment",
       "apiVersion": "extensions/v1beta1",
@@ -270,37 +328,6 @@
         "strategy": {}
       },
       "status": {}
-    },
-    {
-      "kind": "Deployment",
-      "apiVersion": "extensions/v1beta1",
-      "metadata": {
-        "name": "worker",
-        "creationTimestamp": null
-      },
-      "spec": {
-        "replicas": 1,
-        "template": {
-          "metadata": {
-            "creationTimestamp": null,
-            "labels": {
-              "service": "worker"
-            }
-          },
-          "spec": {
-            "containers": [
-              {
-                "name": "worker",
-                "image": "docker/example-voting-app-worker",
-                "resources": {}
-              }
-            ],
-            "restartPolicy": "Always"
-          }
-        },
-        "strategy": {}
-      },
-      "status": {}
     }
   ]
 }

script/test/fixtures/entrypoint-command/output-k8s.json

@@ -39,6 +39,33 @@
         "strategy": {}
       },
       "status": {}
+    },
+    {
+      "kind": "Service",
+      "apiVersion": "v1",
+      "metadata": {
+        "name": "base",
+        "creationTimestamp": null,
+        "labels": {
+          "service": "base"
+        }
+      },
+      "spec": {
+        "ports": [
+          {
+            "name": "headless",
+            "port": 55555,
+            "targetPort": 0
+          }
+        ],
+        "selector": {
+          "service": "base"
+        },
+        "clusterIP": "None"
+      },
+      "status": {
+        "loadBalancer": {}
+      }
     }
   ]
 }