Allow handlers earlier in a request flow to inject a UID for an object

pkg/api/context.go

@@ -22,6 +22,7 @@ import (
 
 	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/auth/user"
+	"k8s.io/kubernetes/pkg/types"
 )
 
 // Context carries values across API boundaries.
@@ -49,11 +50,16 @@ type Context interface {
 // The key type is unexported to prevent collisions
 type key int
 
-// namespaceKey is the context key for the request namespace.
-const namespaceKey key = 0
+const (
+	// namespaceKey is the context key for the request namespace.
+	namespaceKey key = iota
 
-// userKey is the context key for the request user.
-const userKey key = 1
+	// userKey is the context key for the request user.
+	userKey
+
+	// uidKey is the context key for the uid to assign to an object on create.
+	uidKey
+)
 
 // NewContext instantiates a base context object for request flows.
 func NewContext() Context {
@@ -119,3 +125,14 @@ func UserFrom(ctx Context) (user.Info, bool) {
 	user, ok := ctx.Value(userKey).(user.Info)
 	return user, ok
 }
+
+// WithUID returns a copy of parent in which the uid value is set
+func WithUID(parent Context, uid types.UID) Context {
+	return WithValue(parent, uidKey, uid)
+}
+
+// UIDFrom returns the value of the uid key on the ctx
+func UIDFrom(ctx Context) (types.UID, bool) {
+	uid, ok := ctx.Value(uidKey).(types.UID)
+	return uid, ok
+}