Add the kubectl apply command.

pkg/kubectl/apply.go

@@ -0,0 +1,164 @@
+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubectl
+
+import (
+	"encoding/json"
+
+	"k8s.io/kubernetes/pkg/api/meta"
+	"k8s.io/kubernetes/pkg/kubectl/resource"
+)
+
+type debugError interface {
+	DebugError() (msg string, args []interface{})
+}
+
+// LastAppliedConfigAnnotation is the annotation used to store the previous
+// configuration of a resource for use in a three way diff by UpdateApplyAnnotation.
+const LastAppliedConfigAnnotation = kubectlAnnotationPrefix + "last-applied-configuration"
+
+// GetOriginalConfiguration retrieves the original configuration of the object
+// from the annotation, or nil if no annotation was found.
+func GetOriginalConfiguration(info *resource.Info) ([]byte, error) {
+	annotations, err := info.Mapping.MetadataAccessor.Annotations(info.Object)
+	if err != nil {
+		return nil, err
+	}
+
+	if annotations == nil {
+		return nil, nil
+	}
+
+	original, ok := annotations[LastAppliedConfigAnnotation]
+	if !ok {
+		return nil, nil
+	}
+
+	return []byte(original), nil
+}
+
+// SetOriginalConfiguration sets the original configuration of the object
+// as the annotation on the object for later use in computing a three way patch.
+func SetOriginalConfiguration(info *resource.Info, original []byte) error {
+	if len(original) < 1 {
+		return nil
+	}
+
+	// Get the current annotations from the object.
+	annotations, err := info.Mapping.MetadataAccessor.Annotations(info.Object)
+	if err != nil {
+		return err
+	}
+
+	if annotations == nil {
+		annotations = map[string]string{}
+	}
+
+	annotations[LastAppliedConfigAnnotation] = string(original)
+	if err := info.Mapping.MetadataAccessor.SetAnnotations(info.Object, annotations); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// GetModifiedConfiguration retrieves the modified configuration of the object.
+// If annotate is true, it embeds the result as an anotation in the modified
+// configuration. If an object was read from the command input, it will use that
+// version of the object. Otherwise, it will use the version from the server.
+func GetModifiedConfiguration(info *resource.Info, annotate bool) ([]byte, error) {
+	// First serialize the object without the annotation to prevent recursion,
+	// then add that serialization to it as the annotation and serialize it again.
+	var modified []byte
+	if info.VersionedObject != nil {
+		// If an object was read from input, use that version.
+		accessor, err := meta.Accessor(info.VersionedObject)
+		if err != nil {
+			return nil, err
+		}
+
+		// Get the current annotations from the object.
+		annotations := accessor.Annotations()
+		if annotations == nil {
+			annotations = map[string]string{}
+		}
+
+		original := annotations[LastAppliedConfigAnnotation]
+		delete(annotations, LastAppliedConfigAnnotation)
+		accessor.SetAnnotations(annotations)
+		modified, err = json.Marshal(info.VersionedObject)
+		if err != nil {
+			return nil, err
+		}
+
+		if annotate {
+			annotations[LastAppliedConfigAnnotation] = string(modified)
+			accessor.SetAnnotations(annotations)
+			modified, err = json.Marshal(info.VersionedObject)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Restore the object to its original condition.
+		annotations[LastAppliedConfigAnnotation] = original
+		accessor.SetAnnotations(annotations)
+	} else {
+		// Otherwise, use the server side version of the object.
+		accessor := info.Mapping.MetadataAccessor
+		// Get the current annotations from the object.
+		annotations, err := accessor.Annotations(info.Object)
+		if err != nil {
+			return nil, err
+		}
+
+		if annotations == nil {
+			annotations = map[string]string{}
+		}
+
+		original := annotations[LastAppliedConfigAnnotation]
+		delete(annotations, LastAppliedConfigAnnotation)
+		if err := accessor.SetAnnotations(info.Object, annotations); err != nil {
+			return nil, err
+		}
+
+		modified, err = info.Mapping.Codec.Encode(info.Object)
+		if err != nil {
+			return nil, err
+		}
+
+		if annotate {
+			annotations[LastAppliedConfigAnnotation] = string(modified)
+			if err := info.Mapping.MetadataAccessor.SetAnnotations(info.Object, annotations); err != nil {
+				return nil, err
+			}
+
+			modified, err = info.Mapping.Codec.Encode(info.Object)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Restore the object to its original condition.
+		annotations[LastAppliedConfigAnnotation] = original
+		if err := info.Mapping.MetadataAccessor.SetAnnotations(info.Object, annotations); err != nil {
+			return nil, err
+		}
+	}
+
+	return modified, nil
+}