diff --git a/cmd/kubelet/kubelet.go b/cmd/kubelet/kubelet.go
index b3e7a3069ae..d8a919be680 100644
--- a/cmd/kubelet/kubelet.go
+++ b/cmd/kubelet/kubelet.go
@@ -163,9 +163,11 @@ func main() {
 		float32(*registryPullQPS),
 		*registryBurst)
 
-	health.AddHealthChecker("exec", health.NewExecHealthChecker(k))
-	health.AddHealthChecker("http", health.NewHTTPHealthChecker(&http.Client{}))
-	health.AddHealthChecker("tcp", &health.TCPHealthChecker{})
+	// TODO: These should probably become more plugin-ish: register a factory func
+	// in each checker's init(), iterate those here.
+	health.AddHealthChecker(health.NewExecHealthChecker(k))
+	health.AddHealthChecker(health.NewHTTPHealthChecker(&http.Client{}))
+	health.AddHealthChecker(&health.TCPHealthChecker{})
 
 	// start the kubelet
 	go util.Forever(func() { k.Run(cfg.Updates()) }, 0)
diff --git a/pkg/api/errors/errors_test.go b/pkg/api/errors/errors_test.go
index 49edec7880d..01a0a39aaae 100644
--- a/pkg/api/errors/errors_test.go
+++ b/pkg/api/errors/errors_test.go
@@ -29,26 +29,26 @@ import (
 func TestErrorNew(t *testing.T) {
 	err := NewAlreadyExists("test", "1")
 	if !IsAlreadyExists(err) {
-		t.Errorf("expected to be already_exists")
+		t.Errorf("expected to be %s", api.StatusReasonAlreadyExists)
 	}
 	if IsConflict(err) {
-		t.Errorf("expected to not be confict")
+		t.Errorf("expected to not be %s", api.StatusReasonConflict)
 	}
 	if IsNotFound(err) {
 		t.Errorf(fmt.Sprintf("expected to not be %s", api.StatusReasonNotFound))
 	}
 	if IsInvalid(err) {
-		t.Errorf("expected to not be invalid")
+		t.Errorf("expected to not be %s", api.StatusReasonInvalid)
 	}
 
 	if !IsConflict(NewConflict("test", "2", errors.New("message"))) {
 		t.Errorf("expected to be conflict")
 	}
 	if !IsNotFound(NewNotFound("test", "3")) {
-		t.Errorf("expected to be not found")
+		t.Errorf("expected to be %s", api.StatusReasonNotFound)
 	}
 	if !IsInvalid(NewInvalid("test", "2", nil)) {
-		t.Errorf("expected to be invalid")
+		t.Errorf("expected to be %s", api.StatusReasonInvalid)
 	}
 }
 
@@ -122,7 +122,7 @@ func TestNewInvalid(t *testing.T) {
 			t.Errorf("%d: unexpected status: %#v", i, status)
 		}
 		if !reflect.DeepEqual(expected, status.Details) {
-			t.Errorf("%d: expected %#v, got %#v", expected, status.Details)
+			t.Errorf("%d: expected %#v, got %#v", i, expected, status.Details)
 		}
 	}
 }
diff --git a/pkg/api/errors/validation.go b/pkg/api/errors/validation.go
index 6626f0c76bb..bd9ac72d53c 100644
--- a/pkg/api/errors/validation.go
+++ b/pkg/api/errors/validation.go
@@ -28,22 +28,23 @@ import (
 // CauseType in api/types.go.
 type ValidationErrorType string
 
+// TODO: These values are duplicated in api/types.go, but there's a circular dep.  Fix it.
 const (
 	// ValidationErrorTypeNotFound is used to report failure to find a requested value
 	// (e.g. looking up an ID).
-	ValidationErrorTypeNotFound ValidationErrorType = "fieldValueNotFound"
+	ValidationErrorTypeNotFound ValidationErrorType = "FieldValueNotFound"
 	// ValidationErrorTypeRequired is used to report required values that are not
 	// provided (e.g. empty strings, null values, or empty arrays).
-	ValidationErrorTypeRequired ValidationErrorType = "fieldValueRequired"
+	ValidationErrorTypeRequired ValidationErrorType = "FieldValueRequired"
 	// ValidationErrorTypeDuplicate is used to report collisions of values that must be
 	// unique (e.g. unique IDs).
-	ValidationErrorTypeDuplicate ValidationErrorType = "fieldValueDuplicate"
+	ValidationErrorTypeDuplicate ValidationErrorType = "FieldValueDuplicate"
 	// ValidationErrorTypeInvalid is used to report malformed values (e.g. failed regex
 	// match).
-	ValidationErrorTypeInvalid ValidationErrorType = "fieldValueInvalid"
+	ValidationErrorTypeInvalid ValidationErrorType = "FieldValueInvalid"
 	// ValidationErrorTypeNotSupported is used to report valid (as per formatting rules)
 	// values that can not be handled (e.g. an enumerated string).
-	ValidationErrorTypeNotSupported ValidationErrorType = "fieldValueNotSupported"
+	ValidationErrorTypeNotSupported ValidationErrorType = "FieldValueNotSupported"
 )
 
 func ValueOf(t ValidationErrorType) string {
diff --git a/pkg/api/types.go b/pkg/api/types.go
index 1d9a41e8051..a081f0a7e12 100644
--- a/pkg/api/types.go
+++ b/pkg/api/types.go
@@ -100,6 +100,16 @@ type HostDirectory struct {
 
 type EmptyDirectory struct{}
 
+// Protocol defines network protocols supported for things like conatiner ports.
+type Protocol string
+
+const (
+	// ProtocolTCP is the TCP protocol.
+	ProtocolTCP Protocol = "TCP"
+	// ProtocolUDP is the UDP protocol.
+	ProtocolUDP Protocol = "UDP"
+)
+
 // Port represents a network port in a single container.
 type Port struct {
 	// Optional: If specified, this must be a DNS_LABEL.  Each named port
@@ -109,8 +119,8 @@ type Port struct {
 	HostPort int `yaml:"hostPort,omitempty" json:"hostPort,omitempty"`
 	// Required: This must be a valid port number, 0 < x < 65536.
 	ContainerPort int `yaml:"containerPort" json:"containerPort"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 	// Optional: What host IP to bind the external port to.
 	HostIP string `yaml:"hostIP,omitempty" json:"hostIP,omitempty"`
 }
@@ -161,8 +171,6 @@ type ExecAction struct {
 // LivenessProbe describes a liveness probe to be examined to the container.
 // TODO: pass structured data to the actions, and document that data here.
 type LivenessProbe struct {
-	// Type of liveness probe.  Current legal values "http", "tcp"
-	Type string `yaml:"type,omitempty" json:"type,omitempty"`
 	// HTTPGetProbe parameters, required if Type == 'http'
 	HTTPGet *HTTPGetAction `yaml:"httpGet,omitempty" json:"httpGet,omitempty"`
 	// TCPSocketProbe parameter, required if Type == 'tcp'
@@ -381,8 +389,8 @@ type Service struct {
 
 	// Required.
 	Port int `json:"port" yaml:"port"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 
 	// This service's labels.
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty"`
@@ -447,12 +455,12 @@ func (*Binding) IsAnAPIObject() {}
 // import both.
 type Status struct {
 	JSONBase `json:",inline" yaml:",inline"`
-	// One of: "success", "failure", "working" (for operations not yet completed)
+	// One of: "Success", "Failure", "Working" (for operations not yet completed)
 	Status string `json:"status,omitempty" yaml:"status,omitempty"`
 	// A human-readable description of the status of this operation.
 	Message string `json:"message,omitempty" yaml:"message,omitempty"`
 	// A machine-readable description of why this operation is in the
-	// "failure" or "working" status. If this value is empty there
+	// "Failure" or "Working" status. If this value is empty there
 	// is no information available. A Reason clarifies an HTTP status
 	// code but does not override it.
 	Reason StatusReason `json:"reason,omitempty" yaml:"reason,omitempty"`
@@ -487,9 +495,9 @@ type StatusDetails struct {
 
 // Values of Status.Status
 const (
-	StatusSuccess = "success"
-	StatusFailure = "failure"
-	StatusWorking = "working"
+	StatusSuccess = "Success"
+	StatusFailure = "Failure"
+	StatusWorking = "Working"
 )
 
 // StatusReason is an enumeration of possible failure causes.  Each StatusReason
@@ -514,7 +522,7 @@ const (
 	//   "Location" - HTTP header populated with a URL that can retrieved the final
 	//                status of this operation.
 	// Status code 202
-	StatusReasonWorking StatusReason = "working"
+	StatusReasonWorking StatusReason = "Working"
 
 	// StatusReasonNotFound means one or more resources required for this operation
 	// could not be found.
@@ -524,21 +532,21 @@ const (
 	//                   resource.
 	//   "id"   string - the identifier of the missing resource
 	// Status code 404
-	StatusReasonNotFound StatusReason = "not_found"
+	StatusReasonNotFound StatusReason = "NotFound"
 
 	// StatusReasonAlreadyExists means the resource you are creating already exists.
 	// Details (optional):
 	//   "kind" string - the kind attribute of the conflicting resource
 	//   "id"   string - the identifier of the conflicting resource
 	// Status code 409
-	StatusReasonAlreadyExists StatusReason = "already_exists"
+	StatusReasonAlreadyExists StatusReason = "AlreadyExists"
 
 	// StatusReasonConflict means the requested update operation cannot be completed
 	// due to a conflict in the operation. The client may need to alter the request.
 	// Each resource may define custom details that indicate the nature of the
 	// conflict.
 	// Status code 409
-	StatusReasonConflict StatusReason = "conflict"
+	StatusReasonConflict StatusReason = "Conflict"
 
 	// StatusReasonInvalid means the requested create or update operation cannot be
 	// completed due to invalid data provided as part of the request. The client may
@@ -551,7 +559,7 @@ const (
 	//                   provided resource that was invalid.  The code, message, and
 	//                   field attributes will be set.
 	// Status code 422
-	StatusReasonInvalid StatusReason = "invalid"
+	StatusReasonInvalid StatusReason = "Invalid"
 )
 
 // StatusCause provides more information about an api.Status failure, including
@@ -577,25 +585,25 @@ type StatusCause struct {
 
 // CauseType is a machine readable value providing more detail about what
 // occured in a status response. An operation may have multiple causes for a
-// status (whether failure, success, or working).
+// status (whether Failure, Success, or Working).
 type CauseType string
 
 const (
 	// CauseTypeFieldValueNotFound is used to report failure to find a requested value
 	// (e.g. looking up an ID).
-	CauseTypeFieldValueNotFound CauseType = "fieldValueNotFound"
+	CauseTypeFieldValueNotFound CauseType = "FieldValueNotFound"
 	// CauseTypeFieldValueInvalid is used to report required values that are not
 	// provided (e.g. empty strings, null values, or empty arrays).
-	CauseTypeFieldValueRequired CauseType = "fieldValueRequired"
+	CauseTypeFieldValueRequired CauseType = "FieldValueRequired"
 	// CauseTypeFieldValueDuplicate is used to report collisions of values that must be
 	// unique (e.g. unique IDs).
-	CauseTypeFieldValueDuplicate CauseType = "fieldValueDuplicate"
+	CauseTypeFieldValueDuplicate CauseType = "FieldValueDuplicate"
 	// CauseTypeFieldValueInvalid is used to report malformed values (e.g. failed regex
 	// match).
-	CauseTypeFieldValueInvalid CauseType = "fieldValueInvalid"
+	CauseTypeFieldValueInvalid CauseType = "FieldValueInvalid"
 	// CauseTypeFieldValueNotSupported is used to report valid (as per formatting rules)
 	// values that can not be handled (e.g. an enumerated string).
-	CauseTypeFieldValueNotSupported CauseType = "fieldValueNotSupported"
+	CauseTypeFieldValueNotSupported CauseType = "FieldValueNotSupported"
 )
 
 // ServerOp is an operation delivered to API clients.
diff --git a/pkg/api/v1beta1/types.go b/pkg/api/v1beta1/types.go
index 61277c3e801..12131d35ccf 100644
--- a/pkg/api/v1beta1/types.go
+++ b/pkg/api/v1beta1/types.go
@@ -100,6 +100,16 @@ type HostDirectory struct {
 
 type EmptyDirectory struct{}
 
+// Protocol defines network protocols supported for things like conatiner ports.
+type Protocol string
+
+const (
+	// ProtocolTCP is the TCP protocol.
+	ProtocolTCP Protocol = "TCP"
+	// ProtocolUDP is the UDP protocol.
+	ProtocolUDP Protocol = "UDP"
+)
+
 // Port represents a network port in a single container.
 type Port struct {
 	// Optional: If specified, this must be a DNS_LABEL.  Each named port
@@ -109,8 +119,8 @@ type Port struct {
 	HostPort int `yaml:"hostPort,omitempty" json:"hostPort,omitempty"`
 	// Required: This must be a valid port number, 0 < x < 65536.
 	ContainerPort int `yaml:"containerPort" json:"containerPort"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 	// Optional: What host IP to bind the external port to.
 	HostIP string `yaml:"hostIP,omitempty" json:"hostIP,omitempty"`
 }
@@ -171,8 +181,6 @@ type ExecAction struct {
 // LivenessProbe describes a liveness probe to be examined to the container.
 // TODO: pass structured data to the actions, and document that data here.
 type LivenessProbe struct {
-	// Type of liveness probe.  Current legal values "http", "tcp"
-	Type string `yaml:"type,omitempty" json:"type,omitempty"`
 	// HTTPGetProbe parameters, required if Type == 'http'
 	HTTPGet *HTTPGetAction `yaml:"httpGet,omitempty" json:"httpGet,omitempty"`
 	// TCPSocketProbe parameter, required if Type == 'tcp'
@@ -394,8 +402,8 @@ type Service struct {
 
 	// Required.
 	Port int `json:"port" yaml:"port"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 
 	// This service's labels.
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty"`
@@ -463,12 +471,12 @@ func (*Binding) IsAnAPIObject() {}
 // import both.
 type Status struct {
 	JSONBase `json:",inline" yaml:",inline"`
-	// One of: "success", "failure", "working" (for operations not yet completed)
+	// One of: "Success", "Failure", "Working" (for operations not yet completed)
 	Status string `json:"status,omitempty" yaml:"status,omitempty"`
 	// A human-readable description of the status of this operation.
 	Message string `json:"message,omitempty" yaml:"message,omitempty"`
 	// A machine-readable description of why this operation is in the
-	// "failure" or "working" status. If this value is empty there
+	// "Failure" or "Working" status. If this value is empty there
 	// is no information available. A Reason clarifies an HTTP status
 	// code but does not override it.
 	Reason StatusReason `json:"reason,omitempty" yaml:"reason,omitempty"`
@@ -503,9 +511,9 @@ type StatusDetails struct {
 
 // Values of Status.Status
 const (
-	StatusSuccess = "success"
-	StatusFailure = "failure"
-	StatusWorking = "working"
+	StatusSuccess = "Success"
+	StatusFailure = "Failure"
+	StatusWorking = "Working"
 )
 
 // StatusReason is an enumeration of possible failure causes.  Each StatusReason
@@ -530,7 +538,7 @@ const (
 	//   "Location" - HTTP header populated with a URL that can retrieved the final
 	//                status of this operation.
 	// Status code 202
-	StatusReasonWorking StatusReason = "working"
+	StatusReasonWorking StatusReason = "Working"
 
 	// StatusReasonNotFound means one or more resources required for this operation
 	// could not be found.
@@ -540,21 +548,21 @@ const (
 	//                   resource.
 	//   "id"   string - the identifier of the missing resource
 	// Status code 404
-	StatusReasonNotFound StatusReason = "notFound"
+	StatusReasonNotFound StatusReason = "NotFound"
 
 	// StatusReasonAlreadyExists means the resource you are creating already exists.
 	// Details (optional):
 	//   "kind" string - the kind attribute of the conflicting resource
 	//   "id"   string - the identifier of the conflicting resource
 	// Status code 409
-	StatusReasonAlreadyExists StatusReason = "alreadyExists"
+	StatusReasonAlreadyExists StatusReason = "AlreadyExists"
 
 	// StatusReasonConflict means the requested update operation cannot be completed
 	// due to a conflict in the operation. The client may need to alter the request.
 	// Each resource may define custom details that indicate the nature of the
 	// conflict.
 	// Status code 409
-	StatusReasonConflict StatusReason = "conflict"
+	StatusReasonConflict StatusReason = "Conflict"
 )
 
 // StatusCause provides more information about an api.Status failure, including
@@ -580,25 +588,25 @@ type StatusCause struct {
 
 // CauseType is a machine readable value providing more detail about what
 // occured in a status response. An operation may have multiple causes for a
-// status (whether failure, success, or working).
+// status (whether Failure, Success, or Working).
 type CauseType string
 
 const (
 	// CauseTypeFieldValueNotFound is used to report failure to find a requested value
 	// (e.g. looking up an ID).
-	CauseTypeFieldValueNotFound CauseType = "fieldValueNotFound"
+	CauseTypeFieldValueNotFound CauseType = "FieldValueNotFound"
 	// CauseTypeFieldValueInvalid is used to report required values that are not
 	// provided (e.g. empty strings, null values, or empty arrays).
-	CauseTypeFieldValueRequired CauseType = "fieldValueRequired"
+	CauseTypeFieldValueRequired CauseType = "FieldValueRequired"
 	// CauseTypeFieldValueDuplicate is used to report collisions of values that must be
 	// unique (e.g. unique IDs).
-	CauseTypeFieldValueDuplicate CauseType = "fieldValueDuplicate"
+	CauseTypeFieldValueDuplicate CauseType = "FieldValueDuplicate"
 	// CauseTypeFieldValueInvalid is used to report malformed values (e.g. failed regex
 	// match).
-	CauseTypeFieldValueInvalid CauseType = "fieldValueInvalid"
+	CauseTypeFieldValueInvalid CauseType = "FieldValueInvalid"
 	// CauseTypeFieldValueNotSupported is used to report valid (as per formatting rules)
 	// values that can not be handled (e.g. an enumerated string).
-	CauseTypeFieldValueNotSupported CauseType = "fieldValueNotSupported"
+	CauseTypeFieldValueNotSupported CauseType = "FieldValueNotSupported"
 )
 
 // ServerOp is an operation delivered to API clients.
diff --git a/pkg/api/v1beta2/types.go b/pkg/api/v1beta2/types.go
index 61d066dd4f7..7f320f7c807 100644
--- a/pkg/api/v1beta2/types.go
+++ b/pkg/api/v1beta2/types.go
@@ -100,6 +100,16 @@ type HostDirectory struct {
 
 type EmptyDirectory struct{}
 
+// Protocol defines network protocols supported for things like conatiner ports.
+type Protocol string
+
+const (
+	// ProtocolTCP is the TCP protocol.
+	ProtocolTCP Protocol = "TCP"
+	// ProtocolUDP is the UDP protocol.
+	ProtocolUDP Protocol = "UDP"
+)
+
 // Port represents a network port in a single container.
 type Port struct {
 	// Optional: If specified, this must be a DNS_LABEL.  Each named port
@@ -109,8 +119,8 @@ type Port struct {
 	HostPort int `yaml:"hostPort,omitempty" json:"hostPort,omitempty"`
 	// Required: This must be a valid port number, 0 < x < 65536.
 	ContainerPort int `yaml:"containerPort" json:"containerPort"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 	// Optional: What host IP to bind the external port to.
 	HostIP string `yaml:"hostIP,omitempty" json:"hostIP,omitempty"`
 }
@@ -170,8 +180,6 @@ type ExecAction struct {
 // LivenessProbe describes a liveness probe to be examined to the container.
 // TODO: pass structured data to the actions, and document that data here.
 type LivenessProbe struct {
-	// Type of liveness probe.  Current legal values "http", "tcp"
-	Type string `yaml:"type,omitempty" json:"type,omitempty"`
 	// HTTPGetProbe parameters, required if Type == 'http'
 	HTTPGet *HTTPGetAction `yaml:"httpGet,omitempty" json:"httpGet,omitempty"`
 	// TCPSocketProbe parameter, required if Type == 'tcp'
@@ -391,8 +399,8 @@ type Service struct {
 
 	// Required.
 	Port int `json:"port" yaml:"port"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 
 	// This service's labels.
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty"`
@@ -460,12 +468,12 @@ func (*Binding) IsAnAPIObject() {}
 // import both.
 type Status struct {
 	JSONBase `json:",inline" yaml:",inline"`
-	// One of: "success", "failure", "working" (for operations not yet completed)
+	// One of: "Success", "Failure", "Working" (for operations not yet completed)
 	Status string `json:"status,omitempty" yaml:"status,omitempty"`
 	// A human-readable description of the status of this operation.
 	Message string `json:"message,omitempty" yaml:"message,omitempty"`
 	// A machine-readable description of why this operation is in the
-	// "failure" or "working" status. If this value is empty there
+	// "Failure" or "Working" status. If this value is empty there
 	// is no information available. A Reason clarifies an HTTP status
 	// code but does not override it.
 	Reason StatusReason `json:"reason,omitempty" yaml:"reason,omitempty"`
@@ -500,9 +508,9 @@ type StatusDetails struct {
 
 // Values of Status.Status
 const (
-	StatusSuccess = "success"
-	StatusFailure = "failure"
-	StatusWorking = "working"
+	StatusSuccess = "Success"
+	StatusFailure = "Failure"
+	StatusWorking = "Working"
 )
 
 // StatusReason is an enumeration of possible failure causes.  Each StatusReason
@@ -527,7 +535,7 @@ const (
 	//   "Location" - HTTP header populated with a URL that can retrieved the final
 	//                status of this operation.
 	// Status code 202
-	StatusReasonWorking StatusReason = "working"
+	StatusReasonWorking StatusReason = "Working"
 
 	// StatusReasonNotFound means one or more resources required for this operation
 	// could not be found.
@@ -537,21 +545,21 @@ const (
 	//                   resource.
 	//   "id"   string - the identifier of the missing resource
 	// Status code 404
-	StatusReasonNotFound StatusReason = "not_found"
+	StatusReasonNotFound StatusReason = "NotFound"
 
 	// StatusReasonAlreadyExists means the resource you are creating already exists.
 	// Details (optional):
 	//   "kind" string - the kind attribute of the conflicting resource
 	//   "id"   string - the identifier of the conflicting resource
 	// Status code 409
-	StatusReasonAlreadyExists StatusReason = "already_exists"
+	StatusReasonAlreadyExists StatusReason = "AlreadyExists"
 
 	// StatusReasonConflict means the requested update operation cannot be completed
 	// due to a conflict in the operation. The client may need to alter the request.
 	// Each resource may define custom details that indicate the nature of the
 	// conflict.
 	// Status code 409
-	StatusReasonConflict StatusReason = "conflict"
+	StatusReasonConflict StatusReason = "Conflict"
 
 	// StatusReasonInvalid means the requested create or update operation cannot be
 	// completed due to invalid data provided as part of the request. The client may
@@ -564,7 +572,7 @@ const (
 	//                   provided resource that was invalid.  The code, message, and
 	//                   field attributes will be set.
 	// Status code 422
-	StatusReasonInvalid StatusReason = "invalid"
+	StatusReasonInvalid StatusReason = "Invalid"
 )
 
 // StatusCause provides more information about an api.Status failure, including
@@ -590,25 +598,25 @@ type StatusCause struct {
 
 // CauseType is a machine readable value providing more detail about what
 // occured in a status response. An operation may have multiple causes for a
-// status (whether failure, success, or working).
+// status (whether Failure, Success, or Working).
 type CauseType string
 
 const (
 	// CauseTypeFieldValueNotFound is used to report failure to find a requested value
 	// (e.g. looking up an ID).
-	CauseTypeFieldValueNotFound CauseType = "fieldValueNotFound"
+	CauseTypeFieldValueNotFound CauseType = "FieldValueNotFound"
 	// CauseTypeFieldValueInvalid is used to report required values that are not
 	// provided (e.g. empty strings, null values, or empty arrays).
-	CauseTypeFieldValueRequired CauseType = "fieldValueRequired"
+	CauseTypeFieldValueRequired CauseType = "FieldValueRequired"
 	// CauseTypeFieldValueDuplicate is used to report collisions of values that must be
 	// unique (e.g. unique IDs).
-	CauseTypeFieldValueDuplicate CauseType = "fieldValueDuplicate"
+	CauseTypeFieldValueDuplicate CauseType = "FieldValueDuplicate"
 	// CauseTypeFieldValueInvalid is used to report malformed values (e.g. failed regex
 	// match).
-	CauseTypeFieldValueInvalid CauseType = "fieldValueInvalid"
+	CauseTypeFieldValueInvalid CauseType = "FieldValueInvalid"
 	// CauseTypeFieldValueNotSupported is used to report valid (as per formatting rules)
 	// values that can not be handled (e.g. an enumerated string).
-	CauseTypeFieldValueNotSupported CauseType = "fieldValueNotSupported"
+	CauseTypeFieldValueNotSupported CauseType = "FieldValueNotSupported"
 )
 
 // ServerOp is an operation delivered to API clients.
diff --git a/pkg/api/v1beta3/types.go b/pkg/api/v1beta3/types.go
index 661bc855749..26c75c57b22 100644
--- a/pkg/api/v1beta3/types.go
+++ b/pkg/api/v1beta3/types.go
@@ -100,6 +100,16 @@ type HostDirectory struct {
 
 type EmptyDirectory struct{}
 
+// Protocol defines network protocols supported for things like conatiner ports.
+type Protocol string
+
+const (
+	// ProtocolTCP is the TCP protocol.
+	ProtocolTCP Protocol = "TCP"
+	// ProtocolUDP is the UDP protocol.
+	ProtocolUDP Protocol = "UDP"
+)
+
 // Port represents a network port in a single container.
 type Port struct {
 	// Optional: If specified, this must be a DNS_LABEL.  Each named port
@@ -109,8 +119,8 @@ type Port struct {
 	HostPort int `yaml:"hostPort,omitempty" json:"hostPort,omitempty"`
 	// Required: This must be a valid port number, 0 < x < 65536.
 	ContainerPort int `yaml:"containerPort" json:"containerPort"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 	// Optional: What host IP to bind the external port to.
 	HostIP string `yaml:"hostIP,omitempty" json:"hostIP,omitempty"`
 }
@@ -161,8 +171,6 @@ type ExecAction struct {
 // LivenessProbe describes a liveness probe to be examined to the container.
 // TODO: pass structured data to the actions, and document that data here.
 type LivenessProbe struct {
-	// Type of liveness probe.  Current legal values "http", "tcp"
-	Type string `yaml:"type,omitempty" json:"type,omitempty"`
 	// HTTPGetProbe parameters, required if Type == 'http'
 	HTTPGet *HTTPGetAction `yaml:"httpGet,omitempty" json:"httpGet,omitempty"`
 	// TCPSocketProbe parameter, required if Type == 'tcp'
@@ -390,8 +398,8 @@ type Service struct {
 
 	// Required.
 	Port int `json:"port" yaml:"port"`
-	// Optional: Supports "TCP" and "UDP".  Defaults to "TCP".
-	Protocol string `yaml:"protocol,omitempty" json:"protocol,omitempty"`
+	// Optional: Defaults to "TCP".
+	Protocol Protocol `yaml:"protocol,omitempty" json:"protocol,omitempty"`
 
 	// This service's labels.
 	Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty"`
@@ -456,12 +464,12 @@ func (*Binding) IsAnAPIObject() {}
 // import both.
 type Status struct {
 	JSONBase `json:",inline" yaml:",inline"`
-	// One of: "success", "failure", "working" (for operations not yet completed)
+	// One of: "Success", "Failure", "Working" (for operations not yet completed)
 	Status string `json:"status,omitempty" yaml:"status,omitempty"`
 	// A human-readable description of the status of this operation.
 	Message string `json:"message,omitempty" yaml:"message,omitempty"`
 	// A machine-readable description of why this operation is in the
-	// "failure" or "working" status. If this value is empty there
+	// "Failure" or "Working" status. If this value is empty there
 	// is no information available. A Reason clarifies an HTTP status
 	// code but does not override it.
 	Reason StatusReason `json:"reason,omitempty" yaml:"reason,omitempty"`
@@ -496,9 +504,9 @@ type StatusDetails struct {
 
 // Values of Status.Status
 const (
-	StatusSuccess = "success"
-	StatusFailure = "failure"
-	StatusWorking = "working"
+	StatusSuccess = "Success"
+	StatusFailure = "Failure"
+	StatusWorking = "Working"
 )
 
 // StatusReason is an enumeration of possible failure causes.  Each StatusReason
@@ -523,7 +531,7 @@ const (
 	//   "Location" - HTTP header populated with a URL that can retrieved the final
 	//                status of this operation.
 	// Status code 202
-	StatusReasonWorking StatusReason = "working"
+	StatusReasonWorking StatusReason = "Working"
 
 	// StatusReasonNotFound means one or more resources required for this operation
 	// could not be found.
@@ -533,21 +541,21 @@ const (
 	//                   resource.
 	//   "id"   string - the identifier of the missing resource
 	// Status code 404
-	StatusReasonNotFound StatusReason = "not_found"
+	StatusReasonNotFound StatusReason = "NotFound"
 
 	// StatusReasonAlreadyExists means the resource you are creating already exists.
 	// Details (optional):
 	//   "kind" string - the kind attribute of the conflicting resource
 	//   "id"   string - the identifier of the conflicting resource
 	// Status code 409
-	StatusReasonAlreadyExists StatusReason = "already_exists"
+	StatusReasonAlreadyExists StatusReason = "AlreadyExists"
 
 	// StatusReasonConflict means the requested update operation cannot be completed
 	// due to a conflict in the operation. The client may need to alter the request.
 	// Each resource may define custom details that indicate the nature of the
 	// conflict.
 	// Status code 409
-	StatusReasonConflict StatusReason = "conflict"
+	StatusReasonConflict StatusReason = "Conflict"
 
 	// StatusReasonInvalid means the requested create or update operation cannot be
 	// completed due to invalid data provided as part of the request. The client may
@@ -560,7 +568,7 @@ const (
 	//                   provided resource that was invalid.  The code, message, and
 	//                   field attributes will be set.
 	// Status code 422
-	StatusReasonInvalid StatusReason = "invalid"
+	StatusReasonInvalid StatusReason = "Invalid"
 )
 
 // StatusCause provides more information about an api.Status failure, including
@@ -586,25 +594,25 @@ type StatusCause struct {
 
 // CauseType is a machine readable value providing more detail about what
 // occured in a status response. An operation may have multiple causes for a
-// status (whether failure, success, or working).
+// status (whether Failure, Success, or Working).
 type CauseType string
 
 const (
 	// CauseTypeFieldValueNotFound is used to report failure to find a requested value
 	// (e.g. looking up an ID).
-	CauseTypeFieldValueNotFound CauseType = "fieldValueNotFound"
+	CauseTypeFieldValueNotFound CauseType = "FieldValueNotFound"
 	// CauseTypeFieldValueInvalid is used to report required values that are not
 	// provided (e.g. empty strings, null values, or empty arrays).
-	CauseTypeFieldValueRequired CauseType = "fieldValueRequired"
+	CauseTypeFieldValueRequired CauseType = "FieldValueRequired"
 	// CauseTypeFieldValueDuplicate is used to report collisions of values that must be
 	// unique (e.g. unique IDs).
-	CauseTypeFieldValueDuplicate CauseType = "fieldValueDuplicate"
+	CauseTypeFieldValueDuplicate CauseType = "FieldValueDuplicate"
 	// CauseTypeFieldValueInvalid is used to report malformed values (e.g. failed regex
 	// match).
-	CauseTypeFieldValueInvalid CauseType = "fieldValueInvalid"
+	CauseTypeFieldValueInvalid CauseType = "FieldValueInvalid"
 	// CauseTypeFieldValueNotSupported is used to report valid (as per formatting rules)
 	// values that can not be handled (e.g. an enumerated string).
-	CauseTypeFieldValueNotSupported CauseType = "fieldValueNotSupported"
+	CauseTypeFieldValueNotSupported CauseType = "FieldValueNotSupported"
 )
 
 // ServerOp is an operation delivered to API clients.
diff --git a/pkg/api/validation/validation.go b/pkg/api/validation/validation.go
index 01d96b4c463..d209e3c8790 100644
--- a/pkg/api/validation/validation.go
+++ b/pkg/api/validation/validation.go
@@ -78,7 +78,7 @@ func validateHostDir(hostDir *api.HostDirectory) errs.ErrorList {
 	return allErrs
 }
 
-var supportedPortProtocols = util.NewStringSet("TCP", "UDP")
+var supportedPortProtocols = util.NewStringSet(string(api.ProtocolTCP), string(api.ProtocolUDP))
 
 func validatePorts(ports []api.Port) errs.ErrorList {
 	allErrs := errs.ErrorList{}
@@ -106,7 +106,7 @@ func validatePorts(ports []api.Port) errs.ErrorList {
 		}
 		if len(port.Protocol) == 0 {
 			port.Protocol = "TCP"
-		} else if !supportedPortProtocols.Has(strings.ToUpper(port.Protocol)) {
+		} else if !supportedPortProtocols.Has(strings.ToUpper(string(port.Protocol))) {
 			pErrs = append(pErrs, errs.NewFieldNotSupported("protocol", port.Protocol))
 		}
 		allErrs = append(allErrs, pErrs.PrefixIndex(i)...)
@@ -330,7 +330,7 @@ func ValidateService(service *api.Service) errs.ErrorList {
 	}
 	if len(service.Protocol) == 0 {
 		service.Protocol = "TCP"
-	} else if !supportedPortProtocols.Has(strings.ToUpper(service.Protocol)) {
+	} else if !supportedPortProtocols.Has(strings.ToUpper(string(service.Protocol))) {
 		allErrs = append(allErrs, errs.NewFieldNotSupported("protocol", service.Protocol))
 	}
 	if labels.Set(service.Selector).AsSelector().Empty() {
diff --git a/pkg/apiserver/apiserver_test.go b/pkg/apiserver/apiserver_test.go
index c5d713a14a5..79fc5dfc4f4 100644
--- a/pkg/apiserver/apiserver_test.go
+++ b/pkg/apiserver/apiserver_test.go
@@ -706,7 +706,7 @@ func TestAsyncCreateError(t *testing.T) {
 	expectedStatus := &api.Status{
 		Status:  api.StatusFailure,
 		Code:    http.StatusConflict,
-		Reason:  "already_exists",
+		Reason:  "AlreadyExists",
 		Message: expectedErr.Error(),
 		Details: &api.StatusDetails{
 			Kind: "foo",
diff --git a/pkg/apiserver/errors_test.go b/pkg/apiserver/errors_test.go
index 13b3ae4ad83..62f6ed1311e 100644
--- a/pkg/apiserver/errors_test.go
+++ b/pkg/apiserver/errors_test.go
@@ -39,7 +39,7 @@ func TestErrorsToAPIStatus(t *testing.T) {
 		errors.NewAlreadyExists("foo", "bar"): {
 			Status:  api.StatusFailure,
 			Code:    http.StatusConflict,
-			Reason:  "already_exists",
+			Reason:  "AlreadyExists",
 			Message: "foo \"bar\" already exists",
 			Details: &api.StatusDetails{
 				Kind: "foo",
@@ -49,7 +49,7 @@ func TestErrorsToAPIStatus(t *testing.T) {
 		errors.NewConflict("foo", "bar", stderrs.New("failure")): {
 			Status:  api.StatusFailure,
 			Code:    http.StatusConflict,
-			Reason:  "conflict",
+			Reason:  "Conflict",
 			Message: "foo \"bar\" cannot be updated: failure",
 			Details: &api.StatusDetails{
 				Kind: "foo",
diff --git a/pkg/health/exec.go b/pkg/health/exec.go
index efcfec91507..ba95f2f3ce2 100644
--- a/pkg/health/exec.go
+++ b/pkg/health/exec.go
@@ -57,3 +57,7 @@ func (e *ExecHealthChecker) HealthCheck(podFullName string, currentState api.Pod
 	}
 	return Healthy, nil
 }
+
+func (e *ExecHealthChecker) CanCheck(probe *api.LivenessProbe) bool {
+	return probe.Exec != nil
+}
diff --git a/pkg/health/exec_test.go b/pkg/health/exec_test.go
index 44727779a96..28e1a9ccaf3 100644
--- a/pkg/health/exec_test.go
+++ b/pkg/health/exec_test.go
@@ -49,22 +49,19 @@ func TestExec(t *testing.T) {
 	checker := ExecHealthChecker{&fake}
 	tests := []healthCheckTest{
 		// Missing parameters
-		{Unknown, &api.LivenessProbe{Type: "exec"}, true, nil, nil},
+		{Unknown, &api.LivenessProbe{}, true, nil, nil},
 		// Ok
 		{Healthy, &api.LivenessProbe{
-			Type: "exec",
 			Exec: &api.ExecAction{Command: []string{"ls", "-l"}},
 		}, false, []byte("OK"), nil},
 		// Run returns error
 		{Unknown, &api.LivenessProbe{
-			Type: "exec",
 			Exec: &api.ExecAction{
 				Command: []string{"ls", "-l"},
 			},
 		}, true, []byte("OK, NOT"), fmt.Errorf("test error")},
 		// Command error
 		{Unhealthy, &api.LivenessProbe{
-			Type: "exec",
 			Exec: &api.ExecAction{
 				Command: []string{"ls", "-l"},
 			},
diff --git a/pkg/health/health.go b/pkg/health/health.go
index 80c0b604373..c978b00b7ba 100644
--- a/pkg/health/health.go
+++ b/pkg/health/health.go
@@ -36,54 +36,61 @@ const (
 // HealthChecker defines an abstract interface for checking container health.
 type HealthChecker interface {
 	HealthCheck(podFullName string, currentState api.PodState, container api.Container) (Status, error)
+	CanCheck(probe *api.LivenessProbe) bool
 }
 
-// protects checkers
+// protects allCheckers
 var checkerLock = sync.Mutex{}
-var checkers = map[string]HealthChecker{}
+var allCheckers = []HealthChecker{}
 
 // AddHealthChecker adds a health checker to the list of known HealthChecker objects.
 // Any subsequent call to NewHealthChecker will know about this HealthChecker.
-// Panics if 'key' is already present.
-func AddHealthChecker(key string, checker HealthChecker) {
+func AddHealthChecker(checker HealthChecker) {
 	checkerLock.Lock()
 	defer checkerLock.Unlock()
-	if _, found := checkers[key]; found {
-		glog.Fatalf("HealthChecker already defined for key %s.", key)
-	}
-	checkers[key] = checker
+	allCheckers = append(allCheckers, checker)
 }
 
 // NewHealthChecker creates a new HealthChecker which supports multiple types of liveness probes.
 func NewHealthChecker() HealthChecker {
 	checkerLock.Lock()
 	defer checkerLock.Unlock()
-	input := map[string]HealthChecker{}
-	for key, value := range checkers {
-		input[key] = value
-	}
 	return &muxHealthChecker{
-		checkers: input,
+		checkers: append([]HealthChecker{}, allCheckers...),
 	}
 }
 
 // muxHealthChecker bundles multiple implementations of HealthChecker of different types.
 type muxHealthChecker struct {
-	checkers map[string]HealthChecker
+	// Given a LivenessProbe, cycle through each known checker and see if it supports
+	// the specific kind of probe (by returning non-nil).
+	checkers []HealthChecker
+}
+
+func (m *muxHealthChecker) findCheckerFor(probe *api.LivenessProbe) HealthChecker {
+	for i := range m.checkers {
+		if m.checkers[i].CanCheck(probe) {
+			return m.checkers[i]
+		}
+	}
+	return nil
 }
 
 // HealthCheck delegates the health-checking of the container to one of the bundled implementations.
-// It chooses an implementation according to container.LivenessProbe.Type.
-// If there is no matching health checker it returns Unknown, nil.
+// If there is no health checker that can check container it returns Unknown, nil.
 func (m *muxHealthChecker) HealthCheck(podFullName string, currentState api.PodState, container api.Container) (Status, error) {
-	checker, ok := m.checkers[container.LivenessProbe.Type]
-	if !ok || checker == nil {
-		glog.Warningf("Failed to find health checker for %s %s", container.Name, container.LivenessProbe.Type)
+	checker := m.findCheckerFor(container.LivenessProbe)
+	if checker == nil {
+		glog.Warningf("Failed to find health checker for %s %+v", container.Name, container.LivenessProbe)
 		return Unknown, nil
 	}
 	return checker.HealthCheck(podFullName, currentState, container)
 }
 
+func (m *muxHealthChecker) CanCheck(probe *api.LivenessProbe) bool {
+	return m.findCheckerFor(probe) != nil
+}
+
 // findPortByName is a helper function to look up a port in a container by name.
 // Returns the HostPort if found, -1 if not found.
 func findPortByName(container api.Container, portName string) int {
diff --git a/pkg/health/health_test.go b/pkg/health/health_test.go
index 246f869f114..6c08a90bde8 100644
--- a/pkg/health/health_test.go
+++ b/pkg/health/health_test.go
@@ -30,7 +30,7 @@ import (
 const statusServerEarlyShutdown = -1
 
 func TestHealthChecker(t *testing.T) {
-	AddHealthChecker("http", &HTTPHealthChecker{client: &http.Client{}})
+	AddHealthChecker(&HTTPHealthChecker{client: &http.Client{}})
 	var healthCheckerTests = []struct {
 		status int
 		health Status
@@ -64,7 +64,6 @@ func TestHealthChecker(t *testing.T) {
 					Path: "/foo/bar",
 					Host: host,
 				},
-				Type: "http",
 			},
 		}
 		hc := NewHealthChecker()
@@ -100,19 +99,16 @@ func TestFindPortByName(t *testing.T) {
 
 func TestMuxHealthChecker(t *testing.T) {
 	muxHealthCheckerTests := []struct {
-		health    Status
-		probeType string
+		health Status
 	}{
-		{Healthy, "http"},
-		{Unknown, "ftp"},
+		// TODO: This test should run through a few different checker types.
+		{Healthy},
 	}
 	mc := &muxHealthChecker{
-		checkers: make(map[string]HealthChecker),
+		checkers: []HealthChecker{
+			&HTTPHealthChecker{client: &http.Client{}},
+		},
 	}
-	hc := &HTTPHealthChecker{
-		client: &http.Client{},
-	}
-	mc.checkers["http"] = hc
 	for _, muxHealthCheckerTest := range muxHealthCheckerTests {
 		tt := muxHealthCheckerTest
 		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -131,7 +127,6 @@ func TestMuxHealthChecker(t *testing.T) {
 				HTTPGet: &api.HTTPGetAction{},
 			},
 		}
-		container.LivenessProbe.Type = tt.probeType
 		container.LivenessProbe.HTTPGet.Port = util.NewIntOrStringFromString(port)
 		container.LivenessProbe.HTTPGet.Host = host
 		health, err := mc.HealthCheck("test", api.PodState{}, container)
diff --git a/pkg/health/http.go b/pkg/health/http.go
index 8ee739dc59d..18ced9faaf1 100644
--- a/pkg/health/http.go
+++ b/pkg/health/http.go
@@ -105,3 +105,7 @@ func (h *HTTPHealthChecker) HealthCheck(podFullName string, currentState api.Pod
 	}
 	return DoHTTPCheck(formatURL(host, port, path), h.client)
 }
+
+func (h *HTTPHealthChecker) CanCheck(probe *api.LivenessProbe) bool {
+	return probe.HTTPGet != nil
+}
diff --git a/pkg/health/http_test.go b/pkg/health/http_test.go
index d2067231bd6..5fb57217ce8 100644
--- a/pkg/health/http_test.go
+++ b/pkg/health/http_test.go
@@ -51,7 +51,6 @@ func TestGetURLParts(t *testing.T) {
 			Ports: []api.Port{{Name: "found", HostPort: 93}},
 			LivenessProbe: &api.LivenessProbe{
 				HTTPGet: test.probe,
-				Type:    "http",
 			},
 		}
 		host, port, path, err := getURLParts(state, container)
@@ -117,7 +116,6 @@ func TestHTTPHealthChecker(t *testing.T) {
 		container := api.Container{
 			LivenessProbe: &api.LivenessProbe{
 				HTTPGet: test.probe,
-				Type:    "http",
 			},
 		}
 		params := container.LivenessProbe.HTTPGet
diff --git a/pkg/health/tcp.go b/pkg/health/tcp.go
index 1bcfb15f30e..7253c7597d0 100644
--- a/pkg/health/tcp.go
+++ b/pkg/health/tcp.go
@@ -81,3 +81,7 @@ func (t *TCPHealthChecker) HealthCheck(podFullName string, currentState api.PodS
 	}
 	return DoTCPCheck(net.JoinHostPort(host, strconv.Itoa(port)))
 }
+
+func (t *TCPHealthChecker) CanCheck(probe *api.LivenessProbe) bool {
+	return probe.TCPSocket != nil
+}
diff --git a/pkg/health/tcp_test.go b/pkg/health/tcp_test.go
index bd17328a11b..2689ae615d1 100644
--- a/pkg/health/tcp_test.go
+++ b/pkg/health/tcp_test.go
@@ -49,7 +49,6 @@ func TestGetTCPAddrParts(t *testing.T) {
 			Ports: []api.Port{{Name: "found", HostPort: 93}},
 			LivenessProbe: &api.LivenessProbe{
 				TCPSocket: test.probe,
-				Type:      "tcp",
 			},
 		}
 		host, port, err := getTCPAddrParts(state, container)
@@ -95,7 +94,6 @@ func TestTcpHealthChecker(t *testing.T) {
 		container := api.Container{
 			LivenessProbe: &api.LivenessProbe{
 				TCPSocket: test.probe,
-				Type:      "tcp",
 			},
 		}
 		params := container.LivenessProbe.TCPSocket
diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go
index bee489f3d55..5ad944dc245 100644
--- a/pkg/kubelet/kubelet.go
+++ b/pkg/kubelet/kubelet.go
@@ -222,7 +222,7 @@ func makePortsAndBindings(container *api.Container) (map[docker.Port]struct{}, m
 		// Some of this port stuff is under-documented voodoo.
 		// See http://stackoverflow.com/questions/20428302/binding-a-port-to-a-host-interface-using-the-rest-api
 		var protocol string
-		switch strings.ToUpper(port.Protocol) {
+		switch strings.ToUpper(string(port.Protocol)) {
 		case "UDP":
 			protocol = "/udp"
 		case "TCP":
diff --git a/pkg/kubelet/kubelet_test.go b/pkg/kubelet/kubelet_test.go
index 5509bf7b62c..e9ebfbf0307 100644
--- a/pkg/kubelet/kubelet_test.go
+++ b/pkg/kubelet/kubelet_test.go
@@ -457,6 +457,10 @@ func (f *FalseHealthChecker) HealthCheck(podFullName string, state api.PodState,
 	return health.Unhealthy, nil
 }
 
+func (f *FalseHealthChecker) CanCheck(probe *api.LivenessProbe) bool {
+	return true
+}
+
 func TestSyncPodBadHash(t *testing.T) {
 	kubelet, _, fakeDocker := newTestKubelet(t)
 	kubelet.healthChecker = &FalseHealthChecker{}
@@ -522,8 +526,7 @@ func TestSyncPodUnhealthy(t *testing.T) {
 			Containers: []api.Container{
 				{Name: "bar",
 					LivenessProbe: &api.LivenessProbe{
-						// Always returns healthy == false
-						Type: "false",
+					// Always returns healthy == false
 					},
 				},
 			},
diff --git a/pkg/proxy/proxier.go b/pkg/proxy/proxier.go
index ecdf32cf425..339423676fa 100644
--- a/pkg/proxy/proxier.go
+++ b/pkg/proxy/proxier.go
@@ -32,7 +32,7 @@ import (
 
 type serviceInfo struct {
 	port     int
-	protocol string
+	protocol api.Protocol
 	socket   proxySocket
 	timeout  time.Duration
 	mu       sync.Mutex // protects active
@@ -276,8 +276,8 @@ func logTimeout(err error) bool {
 	return false
 }
 
-func newProxySocket(protocol string, host string, port int) (proxySocket, error) {
-	switch strings.ToUpper(protocol) {
+func newProxySocket(protocol api.Protocol, host string, port int) (proxySocket, error) {
+	switch strings.ToUpper(string(protocol)) {
 	case "TCP":
 		listener, err := net.Listen("tcp", net.JoinHostPort(host, strconv.Itoa(port)))
 		if err != nil {
@@ -350,7 +350,7 @@ func (proxier *Proxier) setServiceInfo(service string, info *serviceInfo) {
 // addServiceOnUnusedPort starts listening for a new service, returning the
 // port it's using.  For testing on a system with unknown ports used.  The timeout only applies to UDP
 // connections, for now.
-func (proxier *Proxier) addServiceOnUnusedPort(service, protocol string, timeout time.Duration) (string, error) {
+func (proxier *Proxier) addServiceOnUnusedPort(service string, protocol api.Protocol, timeout time.Duration) (string, error) {
 	sock, err := newProxySocket(protocol, proxier.address, 0)
 	if err != nil {
 		return "", err
diff --git a/pkg/registry/service/rest.go b/pkg/registry/service/rest.go
index 635533ff66e..0394ece8cc5 100644
--- a/pkg/registry/service/rest.go
+++ b/pkg/registry/service/rest.go
@@ -222,9 +222,9 @@ func makeEnvVariableName(str string) string {
 
 func makeLinkVariables(service api.Service, machine string) []api.EnvVar {
 	prefix := makeEnvVariableName(service.ID)
-	protocol := "TCP"
+	protocol := string(api.ProtocolTCP)
 	if service.Protocol != "" {
-		protocol = service.Protocol
+		protocol = string(service.Protocol)
 	}
 	portPrefix := fmt.Sprintf("%s_PORT_%d_%s", prefix, service.Port, strings.ToUpper(protocol))
 	return []api.EnvVar{