add ImageStreams support

This commit adds ImageStream support to the Kedge spec.
A user will be able to define an ImageStream object using the
imageStreams key at the root level of the spec, which is created
by merging the ImageStreamSpec and ObjectMeta.

This commit also includes relevant docs, tests, and examples.

docs/examples/imagestreams/README.md

@@ -0,0 +1,17 @@
+# Image Streams
+
+An image stream can be used to automatically perform an action, such as updating a deployment when a new image is created.
+
+Like most of the Kedge constructs, the `ImageStreamSpec` and `ObjectMeta` have been merged at the same YAML level.
+
+A valid OpenShift `ImageStream` resource can be specified at the root level of the Kedge spec in a field called `imageStreams` like we see in [is.yml](is.yml):
+
+```yaml
+name: webapp
+imageStreams:
+- tags:
+  - from:
+      kind: DockerImage
+      name: centos/httpd-24-centos7:2.4
+    name: "2.4"
+```

docs/examples/imagestreams/is.yml

@@ -0,0 +1,22 @@
+controller: DeploymentConfig
+name: webapp
+containers:
+- image: ""
+triggers:
+- imageChangeParams:
+    automatic: true
+    containerNames:
+    - webapp
+    from:
+      kind: ImageStreamTag
+      name: webapp:2.4
+  type: ImageChange
+services:
+- portMappings:
+  - "8080"
+imageStreams:
+- tags:
+  - from:
+      kind: DockerImage
+      name: centos/httpd-24-centos7:2.4
+    name: "2.4"

docs/file-reference.md

@@ -118,6 +118,8 @@ routes:
   - <routeObject>
 secrets:
   - <secret>
+imageStreams:
+  - <imageStreamObject>
 includeResources:
   - <includeResources>
 ```
@@ -141,6 +143,7 @@ Each "app" (Kedge file) is a Kubernetes <a target="_blank" href="https://kuberne
 | ingresses | array of [ingress object](#ingressobject) | no           | [ingress object](#ingressobject) object |
 | routes | array of [route object](#routeobject) | no           | [route object](#routeobject)  object |
 | secrets | array of [secret](#secret) | no           | [secret](#secret) object |
+| imageStreams | array of [imageStream object](#imagestreamobject) | no           | [imageStream object](#imagestreamobject)  object |
 | includeResources | array of [includeResources](#includeResources) | no           | 
 
 
@@ -314,6 +317,18 @@ secrets:
 | array of [secret](#secret) | no           | [secret](#secret) object |
 
 
+
+## imageStreams
+
+```yaml
+imageStreams:
+- <imageStreamObject>
+```
+
+| Type                         | Required | Description |
+|----------------------------------|--------------|------|
+| array of [imageStream Object](#imagestreamobject) | no           | [imageStream Object](#imagestreamobject) object |
+
 ## includeResources
 
 ```yaml
@@ -869,6 +884,56 @@ secrets:
 Anything [EnvVarSource Spec](https://kubernetes.io/docs/api-reference/v1.8/#envvarsource-v1-core) from Kubernetes can be included within the Kedge file.
 
 
+## imageStreamObject
+
+```yaml
+imageStreams:
+- <imageStreamObject>
+```
+
+> Example
+
+```yaml
+name: rubyapp
+imageStreams:
+- name: rubystream
+  dockerImageRepository: "docker.io/openshift/ruby-20-centos7"
+```
+
+<aside class="notice">
+Each "imageStreamObject" is an OpenShift <a target="_blank" href="https://docs.openshift.org/latest/rest_api/apis-image.openshift.io/v1.ImageStream.html#object-schema">ImageStream Spec</a> with additional Kedge-specific keys.
+</aside>
+
+
+| Type                         | Required | Description |
+|----------------------------------|--------------|------|
+| name | string   | yes          | The name of the ImageStream |
+
+
+### name
+
+```yaml
+name: wordpress
+```
+
+| Type | Required | Description |
+|----------|--------------|-------|
+| string   | yes          | The name of the ImageStream |
+
+### OpenShift extension
+
+> Example extending `imageStreams` with OpenShift ImageStream Spec
+
+```yaml
+name: webapp
+imageStreams:
+- tags:
+  - from:
+      kind: DockerImage
+      name: centos/httpd-24-centos7:latest
+    name: "2.4"
+```
+
 ## includeResources
 
 ```yaml

pkg/cmd/commands.go

@@ -64,7 +64,7 @@ func CreateArtifacts(paths []string, generate bool, args ...string) error {
 		for _, runtimeObject := range ros {
 			switch runtimeObject.GetObjectKind().GroupVersionKind().Kind {
 			// If there is at least one OpenShift resource use oc
-			case "DeploymentConfig", "Route":
+			case "DeploymentConfig", "Route", "ImageStream":
 				useOC = true
 				break
 			}

pkg/spec/resources.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	log "github.com/Sirupsen/logrus"
+	image_v1 "github.com/openshift/origin/pkg/image/apis/image/v1"
 	os_route_v1 "github.com/openshift/origin/pkg/route/apis/route/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	api_v1 "k8s.io/kubernetes/pkg/api/v1"
@@ -125,6 +126,26 @@ func fixSecrets(secrets []SecretMod, appName string) ([]SecretMod, error) {
 	return secrets, nil
 }
 
+func fixImageStreams(imageStreams []ImageStreamSpecMod, appName string) ([]ImageStreamSpecMod, error) {
+
+	// auto populate name only if one ImageStream is specified without any name
+	if len(imageStreams) == 1 && imageStreams[0].Name == "" {
+		imageStreams[0].ObjectMeta.Name = appName
+	}
+
+	for i, is := range imageStreams {
+		if is.Name == "" {
+			return nil, fmt.Errorf("please specify name for app.imageStreams[%d]", i)
+		}
+
+		is.ObjectMeta.Labels = addKeyValueToMap(appLabelKey, appName, is.ObjectMeta.Labels)
+
+		// this should be the last statement in this for loop
+		imageStreams[i] = is
+	}
+	return imageStreams, nil
+}
+
 func fixIngresses(ingresses []IngressSpecMod, appName string) ([]IngressSpecMod, error) {
 
 	// auto populate name only if one ingress is specified without any name
@@ -217,6 +238,12 @@ func (cf *ControllerFields) fixControllerFields() error {
 		return errors.Wrap(err, "unable to fix secrets")
 	}
 
+	// fix imageStreams
+	cf.ImageStreams, err = fixImageStreams(cf.ImageStreams, cf.Name)
+	if err != nil {
+		return errors.Wrap(err, "unable to fix imageStreams")
+	}
+
 	// fix ingresses
 	cf.Ingresses, err = fixIngresses(cf.Ingresses, cf.Name)
 	if err != nil {
@@ -400,6 +427,19 @@ func (app *ControllerFields) createSecrets() ([]runtime.Object, error) {
 	return secrets, nil
 }
 
+func (app *ControllerFields) createImageStreams() ([]runtime.Object, error) {
+	var imageStreams []runtime.Object
+
+	for _, is := range app.ImageStreams {
+		imageStream := &image_v1.ImageStream{
+			ObjectMeta: is.ObjectMeta,
+			Spec:       is.ImageStreamSpec,
+		}
+		imageStreams = append(imageStreams, imageStream)
+	}
+	return imageStreams, nil
+}
+
 // CreateK8sObjects, if given object DeploymentSpecMod, this function reads
 // them and returns kubernetes objects as list of runtime.Object
 // If the deployment is using field 'includeResources' then it will
@@ -431,6 +471,11 @@ func (app *ControllerFields) CreateK8sObjects() ([]runtime.Object, []string, err
 		return nil, nil, errors.Wrap(err, "Unable to create Kubernetes Secrets")
 	}
 
+	iss, err := app.createImageStreams()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "unable to create OpenShift ImageStreams")
+	}
+
 	app.PodSpec.Containers, err = populateContainers(app.Containers, app.ConfigMaps, app.Secrets)
 	if err != nil {
 		return nil, nil, errors.Wrapf(err, "deployment %q", app.Name)
@@ -486,6 +531,9 @@ func (app *ControllerFields) CreateK8sObjects() ([]runtime.Object, []string, err
 	objects = append(objects, secs...)
 	log.Debugf("app: %s, secret: %s\n", app.Name, spew.Sprint(secs))
 
+	objects = append(objects, iss...)
+	log.Debugf("app: %s, imageStreams: %s\n", app.Name, spew.Sprint(iss))
+
 	objects = append(objects, configMap...)
 	log.Debugf("app: %s, configMap: %s\n", app.Name, spew.Sprint(configMap))