Add channels support to the Habitat type

README.md

@@ -61,6 +61,12 @@ To create an example service run:
 This will create a single-pod deployment of an `nginx` Habitat service.
 More examples are located in the [example directory](https://github.com/kinvolk/habitat-operator/tree/master/examples/).
 
+### Promoting a Habitat application
+
+By default, the example service from `examples/standalone/habitat.yml` uses the `staging` channel. To promote it to the `production` channel, use the following example:
+
+    kubectl create -f examples/standalone/habitat-promote.yml
+
 ## Contributing
 
 ### Dependency management

cmd/habitat-operator/main.go

@@ -24,7 +24,6 @@ import (
 	"github.com/go-kit/kit/log/level"
 	flag "github.com/spf13/pflag"
 	apiextensionsclient "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
-	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
 
@@ -66,15 +65,10 @@ func run() int {
 		return 1
 	}
 
-	// Create Habitat CRD.
-	_, crdErr := habitatclient.CreateCRD(apiextensionsclientset)
-	if crdErr != nil {
-		if !apierrors.IsAlreadyExists(crdErr) {
-			level.Error(logger).Log("msg", crdErr)
-			return 1
-		}
-
-		level.Info(logger).Log("msg", "Habitat CRD already exists, continuing")
+	// Create Habitat CRDs.
+	if crdErr := habitatclient.CreateCRDs(apiextensionsclientset, log.With(logger, "coponent", "crd")); crdErr != nil {
+		level.Error(logger).Log("msg", crdErr)
+		return 1
 	} else {
 		level.Info(logger).Log("msg", "created Habitat CRD")
 	}

docs/api.md

@@ -35,3 +35,19 @@ The following is a description of the Habitat operator API. To see manifest exam
 | name | Name of the bind specified in the Habitat configuration files. | string | true |
 | service | Name of the service this bind refers to. | string | true |
 | group | Group of the service this bind refers to. | string | true |
+
+## HabitatPromote
+
+| Field | Description | Scheme | Required |
+| ----- | ----------- | ------ | -------- |
+| metadata |  | [metav1.ObjectMeta](https://kubernetes.io/docs/api-reference/v1.6/#objectmeta-v1-meta) | true |
+| spec |  | [HabitatSpec](#habitatspec) | true |
+| status |  |  | false |
+
+## HabitatPromoteSpec
+
+| Field | Description | Scheme | Required |
+| ----- | ----------- | ------ | -------- |
+| habitatName | Name of the Habitat object to promote. | string | true |
+| oldChannel | Name of the channel the Habitat application is on before the promotion. | string | true |
+| newChannel | Name of the channel the Habitat application is moved to as part of the promotion. | string | true |

examples/rbac/rbac.yml

@@ -30,6 +30,7 @@ rules:
   - habitat.sh
   resources:
   - habitats
+  - habitatpromotes
   verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
 - apiGroups:
   - apps

examples/standalone/habitat-promotion.yml

@@ -0,0 +1,8 @@
+apiVersion: habitat.sh/v1
+kind: HabitatPromotion
+metadata:
+  name: example-standalone-habitat
+spec:
+  habitatName: example-standalone-habitat
+  oldChannel: staging
+  newChannel: production

examples/standalone/habitat.yml

@@ -1,11 +1,14 @@
 apiVersion: habitat.sh/v1
 kind: Habitat
 metadata:
-  name: example-standalone-habitat
+  name: example-standalone-habitat-qqg4x
+  labels:
+    habitat-name: example-standalone-habitat
 spec:
   # the core/nginx habitat service packaged as a Docker image
   image: kinvolk/nginx-hab
   count: 1
+  channel: staging
   service:
     topology: standalone
     # if not present, defaults to "default"

pkg/habitat/apis/cr/v1/register.go

@@ -41,6 +41,8 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
 		&Habitat{},
 		&HabitatList{},
+		&HabitatPromotion{},
+		&HabitatPromotionList{},
 	)
 
 	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)

pkg/habitat/apis/cr/v1/types.go

@@ -29,6 +29,12 @@ const (
 	HabitatNameLabel = "habitat-name"
 
 	TopologyLabel = "topology"
+
+	// HabitatChannelLabel contains the information about stability of application.
+	// Example: 'channel: production'
+	HabitatChannelLabel = "channel"
+
+	HabitatPromotionResourcePlural = "habitatpromotions"
 )
 
 type Habitat struct {
@@ -44,6 +50,9 @@ type HabitatSpec struct {
 	// Image is the Docker image of the Habitat Service.
 	Image   string  `json:"image"`
 	Service Service `json:"service"`
+	// Channel is the information about stability of the application, expressed as a label in Kubernetes.
+	// Optional.
+	Channel string `json:"channel,omitempty"`
 }
 
 type HabitatStatus struct {
@@ -94,8 +103,34 @@ const (
 	TopologyLeader     Topology = "leader"
 )
 
+type HabitatPromotion struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata"`
+	Spec              HabitatPromotionSpec   `json:"spec"`
+	Status            HabitatPromotionStatus `json:"status,omitempty"`
+}
+
+type HabitatPromotionSpec struct {
+	HabitatName string `json:"habitatName"`
+	OldChannel  string `json:"oldChannel"`
+	NewChannel  string `json:"newChannel"`
+}
+
+type HabitatPromotionStatus struct {
+	State   HabitatPromotionState `json:"state,omitempty"`
+	Message string                `json:"message,omitempty"`
+}
+
+type HabitatPromotionState string
+
 type HabitatList struct {
 	metav1.TypeMeta `json:",inline"`
 	metav1.ListMeta `json:"metadata"`
 	Items           []Habitat `json:"items"`
 }
+
+type HabitatPromotionList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata"`
+	Items           []HabitatPromotion `json:"items"`
+}

pkg/habitat/client/cr.go

@@ -15,54 +15,64 @@
 package client
 
 import (
+	"fmt"
 	"reflect"
 	"time"
 
+	"github.com/go-kit/kit/log"
+	"github.com/go-kit/kit/log/level"
 	crv1 "github.com/kinvolk/habitat-operator/pkg/habitat/apis/cr/v1"
 	apiv1 "k8s.io/api/core/v1"
 	apiextensionsv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
 	apiextensionsclient "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/rest"
 )
 
 const (
-	habitatCRDName           = crv1.HabitatResourcePlural + "." + crv1.GroupName
-	habitatResourceShortName = "hab"
+	habitatCRDName                    = crv1.HabitatResourcePlural + "." + crv1.GroupName
+	habitatPromotionCRDName           = crv1.HabitatPromotionResourcePlural + "." + crv1.GroupName
+	habitatResourceShortName          = "hab"
+	habitatPromotionResourceShortName = "habprom"
 
 	pollInterval = 500 * time.Millisecond
 	timeOut      = 10 * time.Second
 )
 
-// CreateCRD creates the Habitat Custom Resource Definition.
+// createCRD creates the Custom Resource Definition with the given name.
 // It checks if creation has completed successfully, and deletes the CRD in case of error.
-func CreateCRD(clientset apiextensionsclient.Interface) (*apiextensionsv1beta1.CustomResourceDefinition, error) {
+func createCRD(clientset apiextensionsclient.Interface, logger log.Logger, crdName, plural, shortName string, kind interface{}) error {
 	crd := &apiextensionsv1beta1.CustomResourceDefinition{
 		ObjectMeta: metav1.ObjectMeta{
-			Name: habitatCRDName,
+			Name: crdName,
 		},
 		Spec: apiextensionsv1beta1.CustomResourceDefinitionSpec{
 			Group:   crv1.GroupName,
 			Version: crv1.SchemeGroupVersion.Version,
 			Scope:   apiextensionsv1beta1.NamespaceScoped,
 			Names: apiextensionsv1beta1.CustomResourceDefinitionNames{
-				Plural:     crv1.HabitatResourcePlural,
-				Kind:       reflect.TypeOf(crv1.Habitat{}).Name(),
-				ShortNames: []string{habitatResourceShortName},
+				Plural:     plural,
+				Kind:       reflect.TypeOf(kind).Name(),
+				ShortNames: []string{shortName},
 			},
 		},
 	}
 
-	_, err := clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Create(crd)
-	if err != nil {
-		return nil, err
+	if _, err := clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Create(crd); err != nil {
+		if !apierrors.IsAlreadyExists(err) {
+			return err
+		}
+		level.Info(logger).Log("msg", fmt.Sprintf("%s CRD already exists, continuing", crdName))
 	}
 
 	// wait for CRD being established.
-	err = wait.Poll(pollInterval, timeOut, func() (bool, error) {
-		crd, err = clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Get(habitatCRDName, metav1.GetOptions{})
+	if err := wait.Poll(pollInterval, timeOut, func() (bool, error) {
+		var err error
+
+		crd, err = clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Get(crdName, metav1.GetOptions{})
 
 		if err != nil {
 			return false, err
@@ -76,26 +86,37 @@ func CreateCRD(clientset apiextensionsclient.Interface) (*apiextensionsv1beta1.C
 				}
 			case apiextensionsv1beta1.NamesAccepted:
 				if cond.Status == apiextensionsv1beta1.ConditionFalse {
-					// TODO re-introduce logging?
-					// fmt.Printf("Error: Name conflict: %v\n", cond.Reason)
+					level.Error(logger).Log("msg", fmt.Sprintf("Error: Name conflict: %v\n", cond.Reason))
 				}
 			}
 		}
 
 		return false, err
-	})
-
-	// delete CRD if there was an error.
-	if err != nil {
-		deleteErr := clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Delete(habitatCRDName, nil)
+	}); err != nil {
+		// delete CRD if there was an error.
+		deleteErr := clientset.ApiextensionsV1beta1().CustomResourceDefinitions().Delete(crdName, nil)
 		if deleteErr != nil {
-			return nil, errors.NewAggregate([]error{err, deleteErr})
+			return errors.NewAggregate([]error{err, deleteErr})
 		}
 
-		return nil, err
+		return err
+	}
+
+	return nil
+}
+
+func CreateCRDs(clientset apiextensionsclient.Interface, logger log.Logger) error {
+	// Create Habitat CRD.
+	if err := createCRD(clientset, logger, habitatCRDName, crv1.HabitatResourcePlural, habitatResourceShortName, crv1.Habitat{}); err != nil {
+		return err
+	}
+
+	// Create HabitatPromotion CRD.
+	if err := createCRD(clientset, logger, habitatPromotionCRDName, crv1.HabitatPromotionResourcePlural, habitatPromotionResourceShortName, crv1.HabitatPromotion{}); err != nil {
+		return err
 	}
 
-	return crd, nil
+	return nil
 }
 
 // WaitForHabitatInstanceProcessed polls the API for a specific Habitat with a state of "Processed".