@@ -12959,6 +12959,43 @@

      "lastTriggeredImageID": {

       "type": "string",

       "description": "used internally to save last used image ID for build"

+     },

+     "from": {

+      "$ref": "v1.ObjectReference",

+      "description": "reference to an ImageStreamTag that will trigger the build"

+     }

+    }

+   },

+   "v1.ObjectReference": {

+    "id": "v1.ObjectReference",

+    "properties": {

+     "kind": {

+      "type": "string",

+      "description": "kind of the referent; see http://releases.k8s.io/v1.0.0/docs/api-conventions.md#types-kinds"

+     },

+     "namespace": {

+      "type": "string",

+      "description": "namespace of the referent; see http://releases.k8s.io/v1.0.0/docs/namespaces.md"

+     },

+     "name": {

+      "type": "string",

+      "description": "name of the referent; see http://releases.k8s.io/v1.0.0/docs/identifiers.md#names"

+     },

+     "uid": {

+      "type": "string",

+      "description": "uid of the referent; see http://releases.k8s.io/v1.0.0/docs/identifiers.md#uids"

+     },

+     "apiVersion": {

+      "type": "string",

+      "description": "API version of the referent"

+     },

+     "resourceVersion": {

+      "type": "string",

+      "description": "specific resourceVersion to which this reference is made, if any: http://releases.k8s.io/v1.0.0/docs/api-conventions.md#concurrency-control-and-consistency"

+     },

+     "fieldPath": {

+      "type": "string",

+      "description": "if referring to a piece of an object instead of an entire object, this string should contain a valid JSON/Go field access statement, such as desiredState.manifest.containers[2]"

      }

     }

    },

@@ -13121,39 +13158,6 @@

      }

     }

    },

-   "v1.ObjectReference": {

-    "id": "v1.ObjectReference",

-    "properties": {

-     "kind": {

-      "type": "string",

-      "description": "kind of the referent; see http://releases.k8s.io/v1.0.0/docs/api-conventions.md#types-kinds"

-     },

-     "namespace": {

-      "type": "string",

-      "description": "namespace of the referent; see http://releases.k8s.io/v1.0.0/docs/namespaces.md"

-     },

-     "name": {

-      "type": "string",

-      "description": "name of the referent; see http://releases.k8s.io/v1.0.0/docs/identifiers.md#names"

-     },

-     "uid": {

-      "type": "string",

-      "description": "uid of the referent; see http://releases.k8s.io/v1.0.0/docs/identifiers.md#uids"

-     },

-     "apiVersion": {

-      "type": "string",

-      "description": "API version of the referent"

-     },

-     "resourceVersion": {

-      "type": "string",

-      "description": "specific resourceVersion to which this reference is made, if any: http://releases.k8s.io/v1.0.0/docs/api-conventions.md#concurrency-control-and-consistency"

-     },

-     "fieldPath": {

-      "type": "string",

-      "description": "if referring to a piece of an object instead of an entire object, this string should contain a valid JSON/Go field access statement, such as desiredState.manifest.containers[2]"

-     }

-    }

-   },

    "v1.EnvVar": {

     "id": "v1.EnvVar",

     "required": [

@@ -13446,6 +13450,10 @@

      "triggeredByImage": {

       "$ref": "v1.ObjectReference",

       "description": "image that triggered this build"

+     },

+     "from": {

+      "$ref": "v1.ObjectReference",

+      "description": "ImageStreamTag that triggered this build"

      }

     }

    },

@@ -822,6 +822,15 @@ func deepCopy_api_BuildRequest(in buildapi.BuildRequest, out *buildapi.BuildRequ

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*api.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1058,6 +1067,15 @@ func deepCopy_api_GitSourceRevision(in buildapi.GitSourceRevision, out *buildapi

 func deepCopy_api_ImageChangeTrigger(in buildapi.ImageChangeTrigger, out *buildapi.ImageChangeTrigger, c *conversion.Cloner) error {

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*api.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1034,6 +1034,14 @@ func convert_api_BuildRequest_To_v1_BuildRequest(in *buildapi.BuildRequest, out

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		out.From = new(v1.ObjectReference)

+		if err := convert_api_ObjectReference_To_v1_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1183,6 +1191,14 @@ func convert_api_ImageChangeTrigger_To_v1_ImageChangeTrigger(in *buildapi.ImageC

 		defaulting.(func(*buildapi.ImageChangeTrigger))(in)

 	}

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		out.From = new(v1.ObjectReference)

+		if err := convert_api_ObjectReference_To_v1_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1382,6 +1398,14 @@ func convert_v1_BuildRequest_To_api_BuildRequest(in *buildapiv1.BuildRequest, ou

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		out.From = new(api.ObjectReference)

+		if err := convert_v1_ObjectReference_To_api_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1531,6 +1555,14 @@ func convert_v1_ImageChangeTrigger_To_api_ImageChangeTrigger(in *buildapiv1.Imag

 		defaulting.(func(*buildapiv1.ImageChangeTrigger))(in)

 	}

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		out.From = new(api.ObjectReference)

+		if err := convert_v1_ObjectReference_To_api_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -803,6 +803,15 @@ func deepCopy_v1_BuildRequest(in buildapiv1.BuildRequest, out *buildapiv1.BuildR

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*v1.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1039,6 +1048,15 @@ func deepCopy_v1_GitSourceRevision(in buildapiv1.GitSourceRevision, out *buildap

 func deepCopy_v1_ImageChangeTrigger(in buildapiv1.ImageChangeTrigger, out *buildapiv1.ImageChangeTrigger, c *conversion.Cloner) error {

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*v1.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1072,6 +1072,14 @@ func convert_api_BuildRequest_To_v1beta3_BuildRequest(in *buildapi.BuildRequest,

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		out.From = new(v1beta3.ObjectReference)

+		if err := convert_api_ObjectReference_To_v1beta3_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1221,6 +1229,14 @@ func convert_api_ImageChangeTrigger_To_v1beta3_ImageChangeTrigger(in *buildapi.I

 		defaulting.(func(*buildapi.ImageChangeTrigger))(in)

 	}

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		out.From = new(v1beta3.ObjectReference)

+		if err := convert_api_ObjectReference_To_v1beta3_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1420,6 +1436,14 @@ func convert_v1beta3_BuildRequest_To_api_BuildRequest(in *buildapiv1beta3.BuildR

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		out.From = new(api.ObjectReference)

+		if err := convert_v1beta3_ObjectReference_To_api_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1569,6 +1593,14 @@ func convert_v1beta3_ImageChangeTrigger_To_api_ImageChangeTrigger(in *buildapiv1

 		defaulting.(func(*buildapiv1beta3.ImageChangeTrigger))(in)

 	}

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		out.From = new(api.ObjectReference)

+		if err := convert_v1beta3_ObjectReference_To_api_ObjectReference(in.From, out.From, s); err != nil {

+			return err

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -811,6 +811,15 @@ func deepCopy_v1beta3_BuildRequest(in buildapiv1beta3.BuildRequest, out *buildap

 	} else {

 		out.TriggeredByImage = nil

 	}

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*v1beta3.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -1047,6 +1056,15 @@ func deepCopy_v1beta3_GitSourceRevision(in buildapiv1beta3.GitSourceRevision, ou

 func deepCopy_v1beta3_ImageChangeTrigger(in buildapiv1beta3.ImageChangeTrigger, out *buildapiv1beta3.ImageChangeTrigger, c *conversion.Cloner) error {

 	out.LastTriggeredImageID = in.LastTriggeredImageID

+	if in.From != nil {

+		if newVal, err := c.DeepCopy(in.From); err != nil {

+			return err

+		} else {

+			out.From = newVal.(*v1beta3.ObjectReference)

+		}

+	} else {

+		out.From = nil

+	}

 	return nil

 }

@@ -356,6 +356,12 @@ type ImageChangeTrigger struct {

 	// LastTriggeredImageID is used internally by the ImageChangeController to save last

 	// used image ID for build

 	LastTriggeredImageID string

+

+	// From is a reference to an ImageStreamTag that will trigger a build when updated

+	// It is optional. If no From is specified, the From image from the build strategy

+	// will be used. Only one ImageChangeTrigger with an empty From reference is allowed in

+	// a build configuration.

+	From *kapi.ObjectReference

 }

 // BuildTriggerPolicy describes a policy for a single trigger that results in a new Build.

@@ -453,6 +459,9 @@ type BuildRequest struct {

 	// TriggeredByImage is the Image that triggered this build.

 	TriggeredByImage *kapi.ObjectReference

+

+	// From is the reference to the ImageStreamTag that triggered the build.

+	From *kapi.ObjectReference

 }

 // BuildLogOptions is the REST options for a build log

@@ -341,6 +341,12 @@ type ImageChangeTrigger struct {

 	// LastTriggeredImageID is used internally by the ImageChangeController to save last

 	// used image ID for build

 	LastTriggeredImageID string `json:"lastTriggeredImageID,omitempty" description:"used internally to save last used image ID for build"`

+

+	// From is a reference to an ImageStreamTag that will trigger a build when updated

+	// It is optional. If no From is specified, the From image from the build strategy

+	// will be used. Only one ImageChangeTrigger with an empty From reference is allowed in

+	// a build configuration.

+	From *kapi.ObjectReference `json:"from,omitempty" description:"reference to an ImageStreamTag that will trigger the build"`

 }

 // BuildTriggerPolicy describes a policy for a single trigger that results in a new Build.

@@ -427,6 +433,9 @@ type BuildRequest struct {

 	// TriggeredByImage is the Image that triggered this build.

 	TriggeredByImage *kapi.ObjectReference `json:"triggeredByImage,omitempty" description:"image that triggered this build"`

+

+	// From is the reference to the ImageStreamTag that triggered the build.

+	From *kapi.ObjectReference `json:"from,omitempty" description:"ImageStreamTag that triggered this build"`

 }

 // BuildLogOptions is the REST options for a build log

@@ -330,6 +330,12 @@ type ImageChangeTrigger struct {

 	// LastTriggeredImageID is used internally by the ImageChangeController to save last

 	// used image ID for build

 	LastTriggeredImageID string `json:"lastTriggeredImageID,omitempty"`

+

+	// From is a reference to an ImageStreamTag that will trigger a build when updated

+	// It is optional. If no From is specified, the From image from the build strategy

+	// will be used. Only one ImageChangeTrigger with an empty From reference is allowed in

+	// a build configuration.

+	From *kapi.ObjectReference `json:"from,omitempty" description:"reference to an ImageStreamTag that will trigger the build"`

 }

 // BuildTriggerPolicy describes a policy for a single trigger that results in a new Build.

@@ -409,6 +415,9 @@ type BuildRequest struct {

 	// TriggeredByImage is the Image that triggered this build.

 	TriggeredByImage *kapi.ObjectReference `json:"triggeredByImage,omitempty"`

+

+	// From is the reference to the ImageStreamTag that triggered the build.

+	From *kapi.ObjectReference `json:"from,omitempty" description:"ImageStreamTag that triggered this build"`

 }

 // BuildLogOptions is the REST options for a build log

@@ -11,6 +11,7 @@ import (

 	oapi "github.com/openshift/origin/pkg/api"

 	buildapi "github.com/openshift/origin/pkg/build/api"

+	buildutil "github.com/openshift/origin/pkg/build/util"

 	imageapi "github.com/openshift/origin/pkg/image/api"

 )

@@ -36,22 +37,43 @@ func ValidateBuildUpdate(build *buildapi.Build, older *buildapi.Build) fielderro

 	return allErrs

 }

+// refKey returns a key for the given ObjectReference. If the ObjectReference

+// doesn't include a namespace, the passed in namespace is used for the reference

+func refKey(namespace string, ref *kapi.ObjectReference) string {

+	if ref == nil || ref.Kind != "ImageStreamTag" {

+		return "nil"

+	}

+	ns := ref.Namespace

+	if ns == "" {

+		ns = namespace

+	}

+	return fmt.Sprintf("%s/%s", ns, ref.Name)

+}

+

 // ValidateBuildConfig tests required fields for a Build.

 func ValidateBuildConfig(config *buildapi.BuildConfig) fielderrors.ValidationErrorList {

 	allErrs := fielderrors.ValidationErrorList{}

 	allErrs = append(allErrs, validation.ValidateObjectMeta(&config.ObjectMeta, true, validation.NameIsDNSSubdomain).Prefix("metadata")...)

-	// allow only one ImageChangeTrigger for now

-	ictCount := 0

+	// image change triggers that refer

+	fromRefs := map[string]struct{}{}

 	for i, trg := range config.Spec.Triggers {

 		allErrs = append(allErrs, validateTrigger(&trg).PrefixIndex(i).Prefix("triggers")...)

-		if trg.Type == buildapi.ImageChangeBuildTriggerType {

-			if ictCount++; ictCount > 1 {

-				allErrs = append(allErrs, fielderrors.NewFieldInvalid("triggers", config.Spec.Triggers, "only one ImageChange trigger is allowed"))

-				break

-			}

+		if trg.Type != buildapi.ImageChangeBuildTriggerType || trg.ImageChange == nil {

+			continue

+		}

+		from := trg.ImageChange.From

+		if from == nil {

+			from = buildutil.GetImageStreamForStrategy(config.Spec.Strategy)

 		}

+		fromKey := refKey(config.Namespace, from)

+		_, exists := fromRefs[fromKey]

+		if exists {

+			allErrs = append(allErrs, fielderrors.NewFieldInvalid("triggers", config.Spec.Triggers, "multiple ImageChange triggers refer to the same image stream tag"))

+		}

+		fromRefs[fromKey] = struct{}{}

 	}

+

 	allErrs = append(allErrs, validateBuildSpec(&config.Spec.BuildSpec).Prefix("spec")...)

 	return allErrs

 }

@@ -311,7 +333,20 @@ func validateTrigger(trigger *buildapi.BuildTriggerPolicy) fielderrors.Validatio

 	case buildapi.ImageChangeBuildTriggerType:

 		if trigger.ImageChange == nil {

 			allErrs = append(allErrs, fielderrors.NewFieldRequired("imageChange"))

+			break

+		}

+		if trigger.ImageChange.From == nil {

+			break

+		}

+		if kind := trigger.ImageChange.From.Kind; kind != "ImageStreamTag" {

+			invalidKindErr := fielderrors.NewFieldInvalid(

+				"imageChange.from.kind",

+				kind,

+				"only an ImageStreamTag type of reference is allowed in an ImageChange trigger.")

+			allErrs = append(allErrs, invalidKindErr)

+			break

 		}

+		allErrs = append(allErrs, validateFromImageReference(trigger.ImageChange.From).Prefix("from")...)

 	default:

 		allErrs = append(allErrs, fielderrors.NewFieldInvalid("type", trigger.Type, "invalid trigger type"))

 	}

@@ -1,7 +1,6 @@

 package validation

 import (

-	"strings"

 	"testing"

 	kapi "github.com/GoogleCloudPlatform/kubernetes/pkg/api"

@@ -168,6 +167,12 @@ func TestBuildConfigValidationSuccess(t *testing.T) {

 					},

 				},

 			},

+			Triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

+				},

+			},

 		},

 	}

 	if result := ValidateBuildConfig(buildConfig); len(result) > 0 {

@@ -213,54 +218,253 @@ func TestBuildConfigValidationFailureRequiredName(t *testing.T) {

 	}

 }

-func TestBuildConfigValidationFailureTooManyICT(t *testing.T) {

-	buildConfig := &buildapi.BuildConfig{

-		ObjectMeta: kapi.ObjectMeta{Name: "bar", Namespace: "foo"},

-		Spec: buildapi.BuildConfigSpec{

-			BuildSpec: buildapi.BuildSpec{

-				Source: buildapi.BuildSource{

-					Type: buildapi.BuildSourceGit,

-					Git: &buildapi.GitBuildSource{

-						URI: "http://github.com/my/repository",

+func TestBuildConfigImageChangeTriggers(t *testing.T) {

+	tests := []struct {

+		name        string

+		triggers    []buildapi.BuildTriggerPolicy

+		expectError bool

+		errorType   fielderrors.ValidationErrorType

+	}{

+		{

+			name: "valid default trigger",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

+				},

+			},

+			expectError: false,

+		},

+		{

+			name: "more than one default trigger",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

+				},

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

+				},

+			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

+		},

+		{

+			name: "missing image change struct",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+				},

+			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeRequired,

+		},

+		{

+			name: "only one default image change trigger",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

+				},

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind: "ImageStreamTag",

+							Name: "myimage:tag",

+						},

 					},

-					ContextDir: "context",

 				},

-				Strategy: buildapi.BuildStrategy{

-					Type:           buildapi.DockerBuildStrategyType,

-					DockerStrategy: &buildapi.DockerBuildStrategy{},

+			},

+			expectError: false,

+		},

+		{

+			name: "invalid reference kind for trigger",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type:        buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{},

 				},

-				Output: buildapi.BuildOutput{

-					To: &kapi.ObjectReference{

-						Kind: "DockerImage",

-						Name: "repository/data",

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind: "DockerImage",

+							Name: "myimage:tag",

+						},

 					},

 				},

 			},

-			Triggers: []buildapi.BuildTriggerPolicy{

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

+		},

+		{

+			name: "empty reference kind for trigger",

+			triggers: []buildapi.BuildTriggerPolicy{

 				{

 					Type:        buildapi.ImageChangeBuildTriggerType,

 					ImageChange: &buildapi.ImageChangeTrigger{},

 				},

 				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Name: "myimage:tag",

+						},

+					},

+				},

+			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

+		},

+		{

+			name: "duplicate imagestreamtag references",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind: "ImageStreamTag",

+							Name: "myimage:tag",

+						},

+					},

+				},

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind: "ImageStreamTag",

+							Name: "myimage:tag",

+						},

+					},

+				},

+			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

+		},

+		{

+			name: "duplicate imagestreamtag - same as strategy ref",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

 					Type:        buildapi.ImageChangeBuildTriggerType,

 					ImageChange: &buildapi.ImageChangeTrigger{},

 				},

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind: "ImageStreamTag",

+							Name: "builderimage:latest",

+						},

+					},

+				},

 			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

+		},

+		{

+			name: "imagestreamtag references with same name, different ns",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind:      "ImageStreamTag",

+							Name:      "myimage:tag",

+							Namespace: "ns1",

+						},

+					},

+				},

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind:      "ImageStreamTag",

+							Name:      "myimage:tag",

+							Namespace: "ns2",

+						},

+					},

+				},

+			},

+			expectError: false,

+		},

+		{

+			name: "imagestreamtag references with same name, same ns",

+			triggers: []buildapi.BuildTriggerPolicy{

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind:      "ImageStreamTag",

+							Name:      "myimage:tag",

+							Namespace: "ns",

+						},

+					},

+				},

+				{

+					Type: buildapi.ImageChangeBuildTriggerType,

+					ImageChange: &buildapi.ImageChangeTrigger{

+						From: &kapi.ObjectReference{

+							Kind:      "ImageStreamTag",

+							Name:      "myimage:tag",

+							Namespace: "ns",

+						},

+					},

+				},

+			},

+			expectError: true,

+			errorType:   fielderrors.ValidationErrorTypeInvalid,

 		},

 	}

-	errors := ValidateBuildConfig(buildConfig)

-	if len(errors) != 1 {

-		t.Fatalf("Unexpected validation errors %v", errors)

-	}

-	err := errors[0].(*fielderrors.ValidationError)

-	if err.Type != fielderrors.ValidationErrorTypeInvalid {

-		t.Errorf("Unexpected error type, expected %s, got %s", fielderrors.ValidationErrorTypeInvalid, err.Type)

-	}

-	if err.Field != "triggers" {

-		t.Errorf("Unexpected field name expected triggers, got %s", err.Field)

-	}

-	if !strings.Contains(err.Detail, "only one ImageChange trigger is allowed") {

-		t.Errorf("Unexpected error details: %s", err.Detail)

+

+	for _, tc := range tests {

+		buildConfig := &buildapi.BuildConfig{

+			ObjectMeta: kapi.ObjectMeta{Name: "bar", Namespace: "foo"},

+			Spec: buildapi.BuildConfigSpec{

+				BuildSpec: buildapi.BuildSpec{

+					Source: buildapi.BuildSource{

+						Type: buildapi.BuildSourceGit,

+						Git: &buildapi.GitBuildSource{

+							URI: "http://github.com/my/repository",

+						},

+						ContextDir: "context",

+					},

+					Strategy: buildapi.BuildStrategy{

+						Type: buildapi.SourceBuildStrategyType,

+						SourceStrategy: &buildapi.SourceBuildStrategy{

+							From: kapi.ObjectReference{

+								Kind: "ImageStreamTag",

+								Name: "builderimage:latest",

+							},

+						},

+					},

+					Output: buildapi.BuildOutput{

+						To: &kapi.ObjectReference{

+							Kind: "DockerImage",

+							Name: "repository/data",

+						},

+					},

+				},

+				Triggers: tc.triggers,

+			},

+		}

+		errors := ValidateBuildConfig(buildConfig)

+		// Check whether an error was returned

+		if hasError := len(errors) > 0; hasError != tc.expectError {

+			t.Errorf("%s: did not get expected result: %#v", tc.name, errors)

+		}

+		// Check whether it's the expected error type

+		if len(errors) > 0 && tc.expectError && tc.errorType != "" {

+			verr, ok := errors[0].(*fielderrors.ValidationError)

+			if !ok {

+				t.Errorf("%s: unexpected error: %#v. Expected ValidationError of type: %s", tc.name, errors[0], verr.Type)

+				continue

+			}

+			if verr.Type != tc.errorType {

+				t.Errorf("%s: unexpected error type. Expected: %s. Got: %s", tc.name, tc.errorType, verr.Type)

+			}

+		}

 	}

 }

@@ -59,21 +59,32 @@ func (c *ImageChangeController) HandleImageRepo(repo *imageapi.ImageStream) erro

 	for _, bc := range c.BuildConfigStore.List() {

 		config := bc.(*buildapi.BuildConfig)

-		from := buildutil.GetImageStreamForStrategy(config.Spec.Strategy)

-		if from == nil || from.Kind != "ImageStreamTag" {

-			continue

-		}

-

-		shouldBuild := false

-		triggeredImage := ""

-		// For every ImageChange trigger find the latest tagged image from the image repository and replace that value

-		// throughout the build strategies. A new build is triggered only if the latest tagged image id or pull spec

-		// differs from the last triggered build recorded on the build config.

+		var (

+			from           *kapi.ObjectReference

+			shouldBuild    = false

+			triggeredImage = ""

+		)

+		// For every ImageChange trigger find the latest tagged image from the image repository and

+		// invoke a build using that image id. A new build is triggered only if the latest tagged image id or pull spec

+		// differs from the last triggered build recorded on the build config for that trigger

 		for _, trigger := range config.Spec.Triggers {

 			if trigger.Type != buildapi.ImageChangeBuildTriggerType {

 				continue

 			}

-			fromStreamName := getImageStreamNameFromReference(from)

+			if trigger.ImageChange.From != nil {

+				from = trigger.ImageChange.From

+			} else {

+				from = buildutil.GetImageStreamForStrategy(config.Spec.Strategy)

+			}

+

+			if from == nil || from.Kind != "ImageStreamTag" {

+				continue

+			}

+			fromStreamName, tag, ok := imageapi.SplitImageStreamTag(from.Name)

+			if !ok {

+				glog.Errorf("Invalid image stream tag: %s in build config %s/%s", from.Name, config.Name, config.Namespace)

+				continue

+			}

 			fromNamespace := from.Namespace

 			if len(fromNamespace) == 0 {

@@ -89,7 +100,6 @@ func (c *ImageChangeController) HandleImageRepo(repo *imageapi.ImageStream) erro

 			// This split is safe because ImageStreamTag names always have the form

 			// name:tag.

-			tag := strings.Split(from.Name, ":")[1]

 			latest := imageapi.LatestTaggedImage(repo, tag)

 			if latest == nil {

 				glog.V(4).Infof("unable to find tagged image: no image recorded for %s/%s:%s", repo.Namespace, repo.Name, tag)

@@ -122,6 +132,7 @@ func (c *ImageChangeController) HandleImageRepo(repo *imageapi.ImageStream) erro

 					Kind: "DockerImage",

 					Name: triggeredImage,

 				},

+				From: from,

 			}

 			if _, err := c.BuildConfigInstantiator.Instantiate(config.Namespace, request); err != nil {

 				if kerrors.IsConflict(err) {

@@ -13,6 +13,7 @@ import (

 	"github.com/GoogleCloudPlatform/kubernetes/pkg/credentialprovider"

 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"

 	buildapi "github.com/openshift/origin/pkg/build/api"

+	buildutil "github.com/openshift/origin/pkg/build/util"

 	"github.com/openshift/origin/pkg/cmd/server/bootstrappolicy"

 	imageapi "github.com/openshift/origin/pkg/image/api"

 )

@@ -98,7 +99,7 @@ func (g *BuildGenerator) FetchServiceAccountSecrets(namespace, serviceAccount st

 	var result []kapi.Secret

 	sa, err := g.ServiceAccounts.ServiceAccounts(namespace).Get(serviceAccount)

 	if err != nil {

-		return result, fmt.Errorf("Error getting push/pull secrets for service account %q: %v", namespace, serviceAccount, err)

+		return result, fmt.Errorf("Error getting push/pull secrets for service account %s/%s: %v", namespace, serviceAccount, err)

 	}

 	for _, ref := range sa.Secrets {

 		secret, err := g.Secrets.Secrets(namespace).Get(ref.Name)

@@ -110,25 +111,62 @@ func (g *BuildGenerator) FetchServiceAccountSecrets(namespace, serviceAccount st

 	return result, nil

 }

+// findImageChangeTrigger finds an image change trigger that has a from that matches the passed in ref

+// if no match is found but there is an image change trigger with a null from, that trigger is returned

+func findImageChangeTrigger(bc *buildapi.BuildConfig, ref *kapi.ObjectReference) *buildapi.ImageChangeTrigger {

+	if ref == nil {

+		return nil

+	}

+	for _, trigger := range bc.Spec.Triggers {

+		if trigger.Type != buildapi.ImageChangeBuildTriggerType {

+			continue

+		}

+		imageChange := trigger.ImageChange

+		triggerRef := imageChange.From

+		if triggerRef == nil {

+			triggerRef = buildutil.GetImageStreamForStrategy(bc.Spec.Strategy)

+			if triggerRef == nil || triggerRef.Kind != "ImageStreamTag" {

+				continue

+			}

+		}

+		triggerNs := triggerRef.Namespace

+		if triggerNs == "" {

+			triggerNs = bc.Namespace

+		}

+		refNs := ref.Namespace

+		if refNs == "" {