kubernetes: Use JSON patch for updating config_map

builtin/providers/kubernetes/patch_operations.go

@@ -0,0 +1,135 @@
+package kubernetes
+
+import (
+	"encoding/json"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+func diffStringMap(pathPrefix string, oldV, newV map[string]interface{}) PatchOperations {
+	ops := make([]PatchOperation, 0, 0)
+
+	pathPrefix = strings.TrimRight(pathPrefix, "/")
+
+	// This is suboptimal for adding whole new map from scratch
+	// or deleting the whole map, but it's actually intention.
+	// There may be some other map items managed outside of TF
+	// and we don't want to touch these.
+
+	for k, _ := range oldV {
+		if _, ok := newV[k]; ok {
+			continue
+		}
+		ops = append(ops, &RemoveOperation{Path: pathPrefix + "/" + k})
+	}
+
+	for k, v := range newV {
+		newValue := v.(string)
+
+		if oldValue, ok := oldV[k].(string); ok {
+			if oldValue == newValue {
+				continue
+			}
+
+			ops = append(ops, &ReplaceOperation{
+				Path:  pathPrefix + "/" + k,
+				Value: newValue,
+			})
+			continue
+		}
+
+		ops = append(ops, &AddOperation{
+			Path:  pathPrefix + "/" + k,
+			Value: newValue,
+		})
+	}
+
+	return ops
+}
+
+type PatchOperations []PatchOperation
+
+func (po PatchOperations) MarshalJSON() ([]byte, error) {
+	var v []PatchOperation = po
+	return json.Marshal(v)
+}
+
+func (po PatchOperations) Equal(ops []PatchOperation) bool {
+	var v []PatchOperation = po
+
+	sort.Slice(v, sortByPathAsc(ops))
+	sort.Slice(ops, sortByPathAsc(ops))
+
+	return reflect.DeepEqual(v, ops)
+}
+
+func sortByPathAsc(ops []PatchOperation) func(i, j int) bool {
+	return func(i, j int) bool {
+		return ops[i].GetPath() < ops[j].GetPath()
+	}
+}
+
+type PatchOperation interface {
+	MarshalJSON() ([]byte, error)
+	GetPath() string
+}
+
+type ReplaceOperation struct {
+	Path  string      `json:"path"`
+	Value interface{} `json:"value"`
+	Op    string      `json:"op"`
+}
+
+func (o *ReplaceOperation) GetPath() string {
+	return o.Path
+}
+
+func (o *ReplaceOperation) MarshalJSON() ([]byte, error) {
+	o.Op = "replace"
+	return json.Marshal(*o)
+}
+
+func (o *ReplaceOperation) String() string {
+	b, _ := o.MarshalJSON()
+	return string(b)
+}
+
+type AddOperation struct {
+	Path  string      `json:"path"`
+	Value interface{} `json:"value"`
+	Op    string      `json:"op"`
+}
+
+func (o *AddOperation) GetPath() string {
+	return o.Path
+}
+
+func (o *AddOperation) MarshalJSON() ([]byte, error) {
+	o.Op = "add"
+	return json.Marshal(*o)
+}
+
+func (o *AddOperation) String() string {
+	b, _ := o.MarshalJSON()
+	return string(b)
+}
+
+type RemoveOperation struct {
+	Path string `json:"path"`
+	Op   string `json:"op"`
+}
+
+func (o *RemoveOperation) GetPath() string {
+	return o.Path
+}
+
+func (o *RemoveOperation) MarshalJSON() ([]byte, error) {
+	o.Op = "remove"
+	return json.Marshal(*o)
+}
+
+func (o *RemoveOperation) String() string {
+	b, _ := o.MarshalJSON()
+	return string(b)
+}

builtin/providers/kubernetes/patch_operations_test.go

@@ -0,0 +1,126 @@
+package kubernetes
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestDiffStringMap(t *testing.T) {
+	testCases := []struct {
+		Path        string
+		Old         map[string]interface{}
+		New         map[string]interface{}
+		ExpectedOps PatchOperations
+	}{
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			New: map[string]interface{}{
+				"one":   "111",
+				"two":   "222",
+				"three": "333",
+			},
+			ExpectedOps: []PatchOperation{
+				&AddOperation{
+					Path:  "/parent/three",
+					Value: "333",
+				},
+			},
+		},
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			New: map[string]interface{}{
+				"one": "111",
+				"two": "abcd",
+			},
+			ExpectedOps: []PatchOperation{
+				&ReplaceOperation{
+					Path:  "/parent/two",
+					Value: "abcd",
+				},
+			},
+		},
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			New: map[string]interface{}{
+				"two":   "abcd",
+				"three": "333",
+			},
+			ExpectedOps: []PatchOperation{
+				&RemoveOperation{Path: "/parent/one"},
+				&ReplaceOperation{
+					Path:  "/parent/two",
+					Value: "abcd",
+				},
+				&AddOperation{
+					Path:  "/parent/three",
+					Value: "333",
+				},
+			},
+		},
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			New: map[string]interface{}{
+				"two": "222",
+			},
+			ExpectedOps: []PatchOperation{
+				&RemoveOperation{Path: "/parent/one"},
+			},
+		},
+		{
+			Path: "/parent/",
+			Old: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			New: map[string]interface{}{},
+			ExpectedOps: []PatchOperation{
+				&RemoveOperation{Path: "/parent/one"},
+				&RemoveOperation{Path: "/parent/two"},
+			},
+		},
+		{
+			Path: "/parent/",
+			Old:  map[string]interface{}{},
+			New: map[string]interface{}{
+				"one": "111",
+				"two": "222",
+			},
+			ExpectedOps: []PatchOperation{
+				&AddOperation{
+					Path:  "/parent/one",
+					Value: "111",
+				},
+				&AddOperation{
+					Path:  "/parent/two",
+					Value: "222",
+				},
+			},
+		},
+	}
+
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			ops := diffStringMap(tc.Path, tc.Old, tc.New)
+			if !tc.ExpectedOps.Equal(ops) {
+				t.Fatalf("Operations don't match.\nExpected: %v\nGiven:    %v\n", tc.ExpectedOps, ops)
+			}
+		})
+	}
+
+}

builtin/providers/kubernetes/resource_kubernetes_config_map.go

@@ -1,9 +1,11 @@
 package kubernetes
 
 import (
+	"fmt"
 	"log"
 
 	"github.com/hashicorp/terraform/helper/schema"
+	pkgApi "k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/errors"
 	api "k8s.io/kubernetes/pkg/api/v1"
 	kubernetes "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_5"
@@ -73,19 +75,22 @@ func resourceKubernetesConfigMapRead(d *schema.ResourceData, meta interface{}) e
 func resourceKubernetesConfigMapUpdate(d *schema.ResourceData, meta interface{}) error {
 	conn := meta.(*kubernetes.Clientset)
 
-	metadata := expandMetadata(d.Get("metadata").([]interface{}))
 	namespace, name := idParts(d.Id())
-	// This is necessary in case the name is generated
-	metadata.Name = name
 
-	cfgMap := api.ConfigMap{
-		ObjectMeta: metadata,
-		Data:       expandStringMap(d.Get("data").(map[string]interface{})),
+	ops := patchMetadata("metadata.0.", "/metadata/", d)
+	if d.HasChange("data") {
+		oldV, newV := d.GetChange("data")
+		diffOps := diffStringMap("/data/", oldV.(map[string]interface{}), newV.(map[string]interface{}))
+		ops = append(ops, diffOps...)
 	}
-	log.Printf("[INFO] Updating config map: %#v", cfgMap)
-	out, err := conn.CoreV1().ConfigMaps(namespace).Update(&cfgMap)
+	data, err := ops.MarshalJSON()
 	if err != nil {
-		return err
+		return fmt.Errorf("Failed to marshal update operations: %s", err)
+	}
+	log.Printf("[INFO] Updating config map %q: %v", name, string(data))
+	out, err := conn.CoreV1().ConfigMaps(namespace).Patch(name, pkgApi.JSONPatchType, data)
+	if err != nil {
+		return fmt.Errorf("Failed to update Config Map: %s", err)
 	}
 	log.Printf("[INFO] Submitted updated config map: %#v", out)
 	d.SetId(buildId(out.ObjectMeta))

builtin/providers/kubernetes/structures.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/hashicorp/terraform/helper/schema"
 	api "k8s.io/kubernetes/pkg/api/v1"
 )
 
@@ -39,6 +40,21 @@ func expandMetadata(in []interface{}) api.ObjectMeta {
 	return meta
 }
 
+func patchMetadata(keyPrefix, pathPrefix string, d *schema.ResourceData) PatchOperations {
+	ops := make([]PatchOperation, 0, 0)
+	if d.HasChange(keyPrefix + "annotations") {
+		oldV, newV := d.GetChange(keyPrefix + "annotations")
+		diffOps := diffStringMap(pathPrefix+"annotations", oldV.(map[string]interface{}), newV.(map[string]interface{}))
+		ops = append(ops, diffOps...)
+	}
+	if d.HasChange(keyPrefix + "labels") {
+		oldV, newV := d.GetChange(keyPrefix + "labels")
+		diffOps := diffStringMap(pathPrefix+"labels", oldV.(map[string]interface{}), newV.(map[string]interface{}))
+		ops = append(ops, diffOps...)
+	}
+	return ops
+}
+
 func expandStringMap(m map[string]interface{}) map[string]string {
 	result := make(map[string]string)
 	for k, v := range m {