Merge "Migrating from consul to mongodb for backend"

7 files changed, 965 insertions, 62 deletions

diff --git a/src/k8splugin/db/consul.go b/src/k8splugin/db/consul.go
index d7507242..a61a4c10 100644
--- a/src/k8splugin/db/consul.go
+++ b/src/k8splugin/db/consul.go
@@ -54,50 +54,64 @@ func NewConsulStore(store ConsulKVStore) (Store, error) {
 
 // HealthCheck verifies if the database is up and running
 func (c *ConsulStore) HealthCheck() error {
-	_, err := c.Read("test")
+	_, err := c.Read("test", "test", "test")
 	if err != nil {
 		return pkgerrors.New("[ERROR] Cannot talk to Datastore. Check if it is running/reachable.")
 	}
 	return nil
 }
 
+// Unmarshal implements any unmarshaling that is needed when using consul
+func (c *ConsulStore) Unmarshal(inp []byte, out interface{}) error {
+	return nil
+}
+
 // Create is used to create a DB entry
-func (c *ConsulStore) Create(key, value string) error {
+func (c *ConsulStore) Create(root, key, tag string, data interface{}) error {
+
+	value, err := Serialize(data)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Serializing input data")
+	}
+
 	p := &api.KVPair{
 		Key:   key,
 		Value: []byte(value),
 	}
-	_, err := c.client.Put(p, nil)
+	_, err = c.client.Put(p, nil)
 	return err
 }
 
 // Read method returns the internalID for a particular externalID
-func (c *ConsulStore) Read(key string) (string, error) {
+func (c *ConsulStore) Read(root, key, tag string) ([]byte, error) {
+	key = root + "/" + key + "/" + tag
 	pair, _, err := c.client.Get(key, nil)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 	if pair == nil {
-		return "", nil
+		return nil, nil
 	}
-	return string(pair.Value), nil
+	return pair.Value, nil
 }
 
 // Delete method removes an internalID from the Database
-func (c *ConsulStore) Delete(key string) error {
+func (c *ConsulStore) Delete(root, key, tag string) error {
 	_, err := c.client.Delete(key, nil)
 	return err
 }
 
 // ReadAll is used to get all ExternalIDs in a namespace
-func (c *ConsulStore) ReadAll(prefix string) ([]string, error) {
-	pairs, _, err := c.client.List(prefix, nil)
+func (c *ConsulStore) ReadAll(root, tag string) (map[string][]byte, error) {
+	pairs, _, err := c.client.List(root, nil)
 	if err != nil {
 		return nil, err
 	}
-	var result []string
+
+	//TODO: Filter results by tag and return it
+	result := make(map[string][]byte)
 	for _, keypair := range pairs {
-		result = append(result, keypair.Key)
+		result[keypair.Key] = keypair.Value
 	}
 
 	return result, nil
diff --git a/src/k8splugin/db/consul_test.go b/src/k8splugin/db/consul_test.go
index ede1a5e9..754112ad 100644
--- a/src/k8splugin/db/consul_test.go
+++ b/src/k8splugin/db/consul_test.go
@@ -107,12 +107,14 @@ func TestConsulCreate(t *testing.T) {
 	}{
 		{
 			label: "Sucessful register a record to Consul Database",
-			input: map[string]string{"key": "test-key", "value": "test-value"},
-			mock:  &mockConsulKVStore{},
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data", "value": "test-value"},
+			mock: &mockConsulKVStore{},
 		},
 		{
 			label: "Fail to create a new record in Consul Database",
-			input: map[string]string{"key": "test-key", "value": "test-value"},
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data", "value": "test-value"},
 			mock: &mockConsulKVStore{
 				Err: pkgerrors.New("DB error"),
 			},
@@ -123,7 +125,8 @@ func TestConsulCreate(t *testing.T) {
 	for _, testCase := range testCases {
 		t.Run(testCase.label, func(t *testing.T) {
 			client, _ := NewConsulStore(testCase.mock)
-			err := client.Create(testCase.input["key"], testCase.input["value"])
+			err := client.Create(testCase.input["root"], testCase.input["key"],
+				testCase.input["tag"], testCase.input["value"])
 			if err != nil {
 				if testCase.expectedError == "" {
 					t.Fatalf("Create method return an un-expected (%s)", err)
@@ -139,18 +142,19 @@ func TestConsulCreate(t *testing.T) {
 func TestConsulRead(t *testing.T) {
 	testCases := []struct {
 		label          string
-		input          string
+		input          map[string]string
 		mock           *mockConsulKVStore
 		expectedError  string
 		expectedResult string
 	}{
 		{
 			label: "Sucessful retrieve a record from Consul Database",
-			input: "test",
+			input: map[string]string{"root": "rbinst", "key": "test",
+				"tag": "data"},
 			mock: &mockConsulKVStore{
 				Items: api.KVPairs{
 					&api.KVPair{
-						Key:   "test",
+						Key:   "rbinst/test/data",
 						Value: []byte("test-value"),
 					},
 				},
@@ -159,12 +163,14 @@ func TestConsulRead(t *testing.T) {
 		},
 		{
 			label: "Fail retrieve a non-existing record from Consul Database",
-			input: "test",
-			mock:  &mockConsulKVStore{},
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
+			mock: &mockConsulKVStore{},
 		},
 		{
 			label: "Fail retrieve a record from Consul Database",
-			input: "test",
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
 			mock: &mockConsulKVStore{
 				Err: pkgerrors.New("DB error"),
 			},
@@ -175,7 +181,8 @@ func TestConsulRead(t *testing.T) {
 	for _, testCase := range testCases {
 		t.Run(testCase.label, func(t *testing.T) {
 			client, _ := NewConsulStore(testCase.mock)
-			result, err := client.Read(testCase.input)
+			result, err := client.Read(testCase.input["root"], testCase.input["key"],
+				testCase.input["tag"])
 			if err != nil {
 				if testCase.expectedError == "" {
 					t.Fatalf("Read method return an un-expected (%s)", err)
@@ -187,7 +194,7 @@ func TestConsulRead(t *testing.T) {
 				if testCase.expectedError != "" && testCase.expectedResult == "" {
 					t.Fatalf("Read method was expecting \"%s\" error message", testCase.expectedError)
 				}
-				if !reflect.DeepEqual(testCase.expectedResult, result) {
+				if !reflect.DeepEqual(testCase.expectedResult, string(result)) {
 
 					t.Fatalf("Read method returned: \n%v\n and it was expected: \n%v", result, testCase.expectedResult)
 				}
@@ -199,14 +206,15 @@ func TestConsulRead(t *testing.T) {
 func TestConsulDelete(t *testing.T) {
 	testCases := []struct {
 		label         string
-		input         string
+		input         map[string]string
 		mock          *mockConsulKVStore
 		expectedError string
 	}{
 		{
 			label: "Sucessful delete a record to Consul Database",
-			input: "test",
-			mock:  &mockConsulKVStore{},
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
+			mock: &mockConsulKVStore{},
 		},
 		{
 			label: "Fail to delete a record in Consul Database",
@@ -220,7 +228,8 @@ func TestConsulDelete(t *testing.T) {
 	for _, testCase := range testCases {
 		t.Run(testCase.label, func(t *testing.T) {
 			client, _ := NewConsulStore(testCase.mock)
-			err := client.Delete(testCase.input)
+			err := client.Delete(testCase.input["root"], testCase.input["key"],
+				testCase.input["tag"])
 			if err != nil {
 				if testCase.expectedError == "" {
 					t.Fatalf("Delete method return an un-expected (%s)", err)
@@ -236,14 +245,15 @@ func TestConsulDelete(t *testing.T) {
 func TestConsulReadAll(t *testing.T) {
 	testCases := []struct {
 		label          string
-		input          string
+		input          map[string]string
 		mock           *mockConsulKVStore
 		expectedError  string
-		expectedResult []string
+		expectedResult map[string][]byte
 	}{
 		{
 			label: "Sucessful retrieve a list from Consul Database",
-			input: "test",
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
 			mock: &mockConsulKVStore{
 				Items: api.KVPairs{
 					&api.KVPair{
@@ -256,16 +266,20 @@ func TestConsulReadAll(t *testing.T) {
 					},
 				},
 			},
-			expectedResult: []string{"test", "test2"},
+			expectedResult: map[string][]byte{"test": []byte("test-value"),
+				"test2": []byte("test-value2")},
 		},
 		{
 			label: "Sucessful retrieve an empty list from Consul Database",
-			input: "test",
-			mock:  &mockConsulKVStore{},
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
+			mock:           &mockConsulKVStore{},
+			expectedResult: map[string][]byte{},
 		},
 		{
 			label: "Fail retrieve a record from Consul Database",
-			input: "test",
+			input: map[string]string{"root": "rbinst", "key": "test-key",
+				"tag": "data"},
 			mock: &mockConsulKVStore{
 				Err: pkgerrors.New("DB error"),
 			},
@@ -276,7 +290,8 @@ func TestConsulReadAll(t *testing.T) {
 	for _, testCase := range testCases {
 		t.Run(testCase.label, func(t *testing.T) {
 			client, _ := NewConsulStore(testCase.mock)
-			result, err := client.ReadAll(testCase.input)
+			result, err := client.ReadAll(testCase.input["root"],
+				testCase.input["tag"])
 			if err != nil {
 				if testCase.expectedError == "" {
 					t.Fatalf("ReadAll method return an un-expected (%s)", err)
diff --git a/src/k8splugin/db/mongo.go b/src/k8splugin/db/mongo.go
new file mode 100644
index 00000000..311f044c
--- /dev/null
+++ b/src/k8splugin/db/mongo.go
@@ -0,0 +1,323 @@
+/*
+ * Copyright 2018 Intel Corporation, Inc
+ *
+ * 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 db
+
+import (
+	"github.com/mongodb/mongo-go-driver/bson"
+	"github.com/mongodb/mongo-go-driver/bson/primitive"
+	"github.com/mongodb/mongo-go-driver/mongo"
+	"github.com/mongodb/mongo-go-driver/mongo/options"
+	pkgerrors "github.com/pkg/errors"
+	"golang.org/x/net/context"
+	"log"
+	"os"
+)
+
+// MongoCollection defines the a subset of MongoDB operations
+// Note: This interface is defined mainly for mock testing
+type MongoCollection interface {
+	InsertOne(ctx context.Context, document interface{},
+		opts ...*options.InsertOneOptions) (*mongo.InsertOneResult, error)
+	FindOne(ctx context.Context, filter interface{},
+		opts ...*options.FindOneOptions) *mongo.SingleResult
+	FindOneAndUpdate(ctx context.Context, filter interface{},
+		update interface{}, opts ...*options.FindOneAndUpdateOptions) *mongo.SingleResult
+	DeleteOne(ctx context.Context, filter interface{},
+		opts ...*options.DeleteOptions) (*mongo.DeleteResult, error)
+	Find(ctx context.Context, filter interface{},
+		opts ...*options.FindOptions) (mongo.Cursor, error)
+}
+
+// MongoStore is an implementation of the db.Store interface
+type MongoStore struct {
+	db *mongo.Database
+}
+
+// This exists only for allowing us to mock the collection object
+// for testing purposes
+var getCollection = func(coll string, m *MongoStore) MongoCollection {
+	return m.db.Collection(coll)
+}
+
+// This exists only for allowing us to mock the DecodeBytes function
+// Mainly because we cannot construct a SingleResult struct from our
+// tests. All fields in that struct are private.
+var decodeBytes = func(sr *mongo.SingleResult) (bson.Raw, error) {
+	return sr.DecodeBytes()
+}
+
+// NewMongoStore initializes a Mongo Database with the name provided
+// If a database with that name exists, it will be returned
+func NewMongoStore(name string, store *mongo.Database) (Store, error) {
+	if store == nil {
+		ip := "mongodb://" + os.Getenv("DATABASE_IP") + ":27017"
+		mongoClient, err := mongo.NewClient(ip)
+		if err != nil {
+			return nil, err
+		}
+
+		err = mongoClient.Connect(context.Background())
+		if err != nil {
+			return nil, err
+		}
+		store = mongoClient.Database(name)
+	}
+
+	return &MongoStore{
+		db: store,
+	}, nil
+}
+
+// HealthCheck verifies if the database is up and running
+func (m *MongoStore) HealthCheck() error {
+
+	_, err := decodeBytes(m.db.RunCommand(context.Background(), bson.D{{"serverStatus", 1}}))
+	if err != nil {
+		return pkgerrors.Wrap(err, "Error getting server status")
+	}
+
+	return nil
+}
+
+// validateParams checks to see if any parameters are empty
+func (m *MongoStore) validateParams(args ...string) bool {
+	for _, v := range args {
+		if v == "" {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Create is used to create a DB entry
+func (m *MongoStore) Create(coll, key, tag string, data interface{}) error {
+	if data == nil || !m.validateParams(coll, key, tag) {
+		return pkgerrors.New("No Data to store")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Insert the data and then add the objectID to the masterTable
+	res, err := c.InsertOne(ctx, bson.D{
+		{tag, data},
+	})
+	if err != nil {
+		return pkgerrors.Errorf("Error inserting into database: %s", err.Error())
+	}
+
+	//Add objectID of created data to masterKey document
+	//Create masterkey document if it does not exist
+	filter := bson.D{{"key", key}}
+
+	_, err = decodeBytes(
+		c.FindOneAndUpdate(
+			ctx,
+			filter,
+			bson.D{
+				{"$set", bson.D{
+					{tag, res.InsertedID},
+				}},
+			},
+			options.FindOneAndUpdate().SetUpsert(true).SetReturnDocument(options.After)))
+
+	if err != nil {
+		return pkgerrors.Errorf("Error updating master table: %s", err.Error())
+	}
+
+	return nil
+}
+
+// Unmarshal implements an unmarshaler for bson data that
+// is produced from the mongo database
+func (m *MongoStore) Unmarshal(inp []byte, out interface{}) error {
+	err := bson.Unmarshal(inp, out)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Unmarshaling bson")
+	}
+	return nil
+}
+
+// Read method returns the data stored for this key and for this particular tag
+func (m *MongoStore) Read(coll, key, tag string) ([]byte, error) {
+	if !m.validateParams(coll, key, tag) {
+		return nil, pkgerrors.New("Mandatory fields are missing")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Get the masterkey document based on given key
+	filter := bson.D{{"key", key}}
+	keydata, err := decodeBytes(c.FindOne(context.Background(), filter))
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error finding master table: %s", err.Error())
+	}
+
+	//Read the tag objectID from document
+	tagoid, ok := keydata.Lookup(tag).ObjectIDOK()
+	if !ok {
+		return nil, pkgerrors.Errorf("Error finding objectID for tag %s", tag)
+	}
+
+	//Use tag objectID to read the data from store
+	filter = bson.D{{"_id", tagoid}}
+	tagdata, err := decodeBytes(c.FindOne(ctx, filter))
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error reading found object: %s", err.Error())
+	}
+
+	//Return the data as a byte array
+	return tagdata.Lookup(tag).Value, nil
+}
+
+// Helper function that deletes an object by its ID
+func (m *MongoStore) deleteObjectByID(coll string, objID primitive.ObjectID) error {
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	_, err := c.DeleteOne(ctx, bson.D{{"_id", objID}})
+	if err != nil {
+		return pkgerrors.Errorf("Error Deleting from database: %s", err.Error())
+	}
+
+	log.Printf("Deleted Obj with ID %s", objID.String())
+	return nil
+}
+
+// Delete method removes a document from the Database that matches key
+// TODO: delete all referenced docs if tag is empty string
+func (m *MongoStore) Delete(coll, key, tag string) error {
+	if !m.validateParams(coll, key, tag) {
+		return pkgerrors.New("Mandatory fields are missing")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Get the masterkey document based on given key
+	filter := bson.D{{"key", key}}
+	//Remove the tag ID entry from masterkey table
+	update := bson.D{
+		{
+			"$unset", bson.D{
+				{tag, ""},
+			},
+		},
+	}
+	keydata, err := decodeBytes(c.FindOneAndUpdate(ctx, filter, update,
+		options.FindOneAndUpdate().SetReturnDocument(options.Before)))
+	if err != nil {
+		return pkgerrors.Errorf("Error decoding master table after update: %s",
+			err.Error())
+	}
+
+	//Read the tag objectID from document
+	elems, err := keydata.Elements()
+	if err != nil {
+		return pkgerrors.Errorf("Error reading elements from database: %s", err.Error())
+	}
+
+	tagoid, ok := keydata.Lookup(tag).ObjectIDOK()
+	if !ok {
+		return pkgerrors.Errorf("Error finding objectID for tag %s", tag)
+	}
+
+	//Use tag objectID to read the data from store
+	err = m.deleteObjectByID(coll, tagoid)
+	if err != nil {
+		return pkgerrors.Errorf("Error deleting from database: %s", err.Error())
+	}
+
+	//Delete master table if no more tags left
+	//_id, key and tag should be elements in before doc
+	//if master table needs to be removed too
+	if len(elems) == 3 {
+		keyid, ok := keydata.Lookup("_id").ObjectIDOK()
+		if !ok {
+			return pkgerrors.Errorf("Error finding objectID for key %s", key)
+		}
+		err = m.deleteObjectByID(coll, keyid)
+		if err != nil {
+			return pkgerrors.Errorf("Error deleting master table from database: %s", err.Error())
+		}
+	}
+
+	return nil
+}
+
+// ReadAll is used to get all documents in db of a particular tag
+func (m *MongoStore) ReadAll(coll, tag string) (map[string][]byte, error) {
+	if !m.validateParams(coll, tag) {
+		return nil, pkgerrors.New("Missing collection or tag name")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Get all master tables in this collection
+	filter := bson.D{
+		{"key", bson.D{
+			{"$exists", true},
+		}},
+	}
+	cursor, err := c.Find(ctx, filter)
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error reading from database: %s", err.Error())
+	}
+	defer cursor.Close(ctx)
+
+	//Iterate over all the master tables
+	result := make(map[string][]byte)
+	for cursor.Next(ctx) {
+		d, err := cursor.DecodeBytes()
+		if err != nil {
+			log.Printf("Unable to decode data in Readall: %s", err.Error())
+			continue
+		}
+
+		//Read key of each master table
+		key, ok := d.Lookup("key").StringValueOK()
+		if !ok {
+			log.Printf("Unable to read key string from mastertable %s", err.Error())
+			continue
+		}
+
+		//Get objectID of tag document
+		tid, ok := d.Lookup(tag).ObjectIDOK()
+		if !ok {
+			log.Printf("Did not find tag: %s", tag)
+			continue
+		}
+
+		//Find tag document and unmarshal it into []byte
+		tagData, err := decodeBytes(c.FindOne(ctx, bson.D{{"_id", tid}}))
+		if err != nil {
+			log.Printf("Unable to decode tag data %s", err.Error())
+			continue
+		}
+		result[key] = tagData.Lookup(tag).Value
+	}
+
+	if len(result) == 0 {
+		return result, pkgerrors.Errorf("Did not find any objects with tag: %s", tag)
+	}
+
+	return result, nil
+}
diff --git a/src/k8splugin/db/mongo_test.go b/src/k8splugin/db/mongo_test.go
new file mode 100644
index 00000000..1663e774
--- /dev/null
+++ b/src/k8splugin/db/mongo_test.go
@@ -0,0 +1,530 @@
+// +build unit
+
+/*
+ * Copyright 2018 Intel Corporation, Inc
+ *
+ * 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 db
+
+import (
+	"bytes"
+	"context"
+	"github.com/mongodb/mongo-go-driver/bson"
+	"github.com/mongodb/mongo-go-driver/mongo"
+	"github.com/mongodb/mongo-go-driver/mongo/options"
+	pkgerrors "github.com/pkg/errors"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// Implements the mongo.Cursor interface
+type mockCursor struct {
+	mongo.Cursor
+	err   error
+	bson  bson.Raw
+	count int
+}
+
+func (mc *mockCursor) Next(ctx context.Context) bool {
+	if mc.count > 0 {
+		mc.count = mc.count - 1
+		return true
+	}
+	return false
+}
+
+func (mc *mockCursor) DecodeBytes() (bson.Raw, error) {
+	return mc.bson, mc.err
+}
+
+func (mc *mockCursor) Close(ctx context.Context) error {
+	return nil
+}
+
+//Implements the functions used currently in mongo.go
+type mockCollection struct {
+	Err     error
+	mCursor mongo.Cursor
+}
+
+func (c *mockCollection) InsertOne(ctx context.Context, document interface{},
+	opts ...*options.InsertOneOptions) (*mongo.InsertOneResult, error) {
+
+	if c.Err != nil {
+		return nil, c.Err
+	}
+
+	return &mongo.InsertOneResult{InsertedID: "_id1234"}, nil
+}
+
+func (c *mockCollection) FindOne(ctx context.Context, filter interface{},
+	opts ...*options.FindOneOptions) *mongo.SingleResult {
+
+	return &mongo.SingleResult{}
+}
+
+func (c *mockCollection) FindOneAndUpdate(ctx context.Context, filter interface{},
+	update interface{}, opts ...*options.FindOneAndUpdateOptions) *mongo.SingleResult {
+
+	return &mongo.SingleResult{}
+}
+
+func (c *mockCollection) DeleteOne(ctx context.Context, filter interface{},
+	opts ...*options.DeleteOptions) (*mongo.DeleteResult, error) {
+
+	return nil, c.Err
+}
+
+func (c *mockCollection) Find(ctx context.Context, filter interface{},
+	opts ...*options.FindOptions) (mongo.Cursor, error) {
+
+	return c.mCursor, c.Err
+}
+
+func TestCreate(t *testing.T) {
+	testCases := []struct {
+		label         string
+		input         map[string]interface{}
+		mockColl      *mockCollection
+		bson          bson.Raw
+		expectedError string
+	}{
+		{
+			label: "Successfull creation of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "tagName",
+				"data": "Data In String Format",
+			},
+			bson:     bson.Raw{'\x08', '\x00', '\x00', '\x00', '\x0A', 'x', '\x00', '\x00'},
+			mockColl: &mockCollection{},
+		},
+		{
+			label: "UnSuccessfull creation of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "tagName",
+				"data": "Data In String Format",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"key":  "",
+				"tag":  "",
+				"data": "",
+			},
+			expectedError: "No Data to store",
+			mockColl:      &mockCollection{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			m, _ := NewMongoStore("name", &mongo.Database{})
+			// Override the getCollection function with our mocked version
+			getCollection = func(coll string, m *MongoStore) MongoCollection {
+				return testCase.mockColl
+			}
+
+			decodeBytes = func(sr *mongo.SingleResult) (bson.Raw, error) {
+				return testCase.bson, testCase.mockColl.Err
+			}
+
+			err := m.Create(testCase.input["coll"].(string), testCase.input["key"].(string),
+				testCase.input["tag"].(string), testCase.input["data"])
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Create method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Create method returned an error (%s)", err)
+				}
+			}
+		})
+	}
+}
+
+func TestRead(t *testing.T) {
+	testCases := []struct {
+		label         string
+		input         map[string]interface{}
+		mockColl      *mockCollection
+		bson          bson.Raw
+		expectedError string
+		expected      []byte
+	}{
+		{
+			label: "Successfull Read of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "metadata",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : "b82c4bb1-09ff-6093-4d58-8327b94e1e20",
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+				'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+				'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+				'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+				'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+				'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+				'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+				'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+				'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+				'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+				'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+				'\xfd', '\x00',
+			},
+			mockColl: &mockCollection{},
+			// This is not the document because we are mocking decodeBytes
+			expected: []byte{92, 17, 81, 86, 201, 117, 80, 71, 227, 24, 187, 253},
+		},
+		{
+			label: "UnSuccessfull Read of entry: object not found",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "badtag",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : "b82c4bb1-09ff-6093-4d58-8327b94e1e20",
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+				'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+				'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+				'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+				'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+				'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+				'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+				'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+				'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+				'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+				'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+				'\xfd', '\x00',
+			},
+			mockColl:      &mockCollection{},
+			expectedError: "Error finding objectID",
+		},
+		{
+			label: "UnSuccessfull Read of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "tagName",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"key":  "",
+				"tag":  "",
+			},
+			expectedError: "Mandatory fields are missing",
+			mockColl:      &mockCollection{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			m, _ := NewMongoStore("name", &mongo.Database{})
+			// Override the getCollection function with our mocked version
+			getCollection = func(coll string, m *MongoStore) MongoCollection {
+				return testCase.mockColl
+			}
+
+			decodeBytes = func(sr *mongo.SingleResult) (bson.Raw, error) {
+				return testCase.bson, testCase.mockColl.Err
+			}
+			got, err := m.Read(testCase.input["coll"].(string), testCase.input["key"].(string),
+				testCase.input["tag"].(string))
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Read method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Read method returned an error (%s)", err)
+				}
+			} else {
+				if bytes.Compare(got, testCase.expected) != 0 {
+					t.Fatalf("Read returned unexpected data: %s, expected: %s",
+						string(got), testCase.expected)
+				}
+			}
+		})
+	}
+}
+
+func TestDelete(t *testing.T) {
+	testCases := []struct {
+		label         string
+		input         map[string]interface{}
+		mockColl      *mockCollection
+		bson          bson.Raw
+		expectedError string
+	}{
+		{
+			label: "Successfull Delete of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "metadata",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : "b82c4bb1-09ff-6093-4d58-8327b94e1e20",
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+				'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+				'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+				'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+				'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+				'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+				'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+				'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+				'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+				'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+				'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+				'\xfd', '\x00',
+			},
+			mockColl: &mockCollection{},
+		},
+		{
+			label: "UnSuccessfull Delete of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "tagName",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+		{
+			label: "UnSuccessfull Delete, key not found",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  "keyvalue",
+				"tag":  "tagName",
+			},
+			bson: bson.Raw{
+				'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+				'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+				'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+				'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+				'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+				'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+				'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+				'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+				'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+				'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+				'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+				'\xfd', '\x00',
+			},
+			mockColl:      &mockCollection{},
+			expectedError: "Error finding objectID",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"key":  "",
+				"tag":  "",
+			},
+			expectedError: "Mandatory fields are missing",
+			mockColl:      &mockCollection{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			m, _ := NewMongoStore("name", &mongo.Database{})
+			// Override the getCollection function with our mocked version
+			getCollection = func(coll string, m *MongoStore) MongoCollection {
+				return testCase.mockColl
+			}
+
+			decodeBytes = func(sr *mongo.SingleResult) (bson.Raw, error) {
+				return testCase.bson, testCase.mockColl.Err
+			}
+			err := m.Delete(testCase.input["coll"].(string), testCase.input["key"].(string),
+				testCase.input["tag"].(string))
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Delete method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Delete method returned an error (%s)", err)
+				}
+			}
+		})
+	}
+}
+
+func TestReadAll(t *testing.T) {
+	testCases := []struct {
+		label         string
+		input         map[string]interface{}
+		mockColl      *mockCollection
+		bson          bson.Raw
+		expectedError string
+		expected      map[string][]byte
+	}{
+		{
+			label: "Successfully Read all entries",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"tag":  "metadata",
+			},
+			mockColl: &mockCollection{
+				mCursor: &mockCursor{
+					// Binary form of
+					// {
+					//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+					//  "key" : "b82c4bb1-09ff-6093-4d58-8327b94e1e20",
+					//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+					// }
+					bson: bson.Raw{
+						'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+						'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+						'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+						'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+						'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+						'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+						'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+						'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+						'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+						'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+						'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+						'\xfd', '\x00',
+					},
+					count: 1,
+				},
+			},
+			expected: map[string][]byte{
+				"b82c4bb1-09ff-6093-4d58-8327b94e1e20": []byte{
+					92, 17, 81, 86, 201, 117, 80, 71, 227, 24, 187, 253},
+			},
+		},
+		{
+			label: "UnSuccessfully Read of all entries",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"tag":  "tagName",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+		{
+			label: "UnSuccessfull Readall, tag not found",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"tag":  "tagName",
+			},
+			mockColl: &mockCollection{
+				mCursor: &mockCursor{
+					// Binary form of
+					// {
+					//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+					//  "key" : "b82c4bb1-09ff-6093-4d58-8327b94e1e20",
+					//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+					// }
+					bson: bson.Raw{
+						'\x5a', '\x00', '\x00', '\x00', '\x07', '\x5f', '\x69', '\x64',
+						'\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f', '\xf8',
+						'\x56', '\x54', '\x24', '\x8a', '\xe1', '\x02', '\x6b', '\x65',
+						'\x79', '\x00', '\x25', '\x00', '\x00', '\x00', '\x62', '\x38',
+						'\x32', '\x63', '\x34', '\x62', '\x62', '\x31', '\x2d', '\x30',
+						'\x39', '\x66', '\x66', '\x2d', '\x36', '\x30', '\x39', '\x33',
+						'\x2d', '\x34', '\x64', '\x35', '\x38', '\x2d', '\x38', '\x33',
+						'\x32', '\x37', '\x62', '\x39', '\x34', '\x65', '\x31', '\x65',
+						'\x32', '\x30', '\x00', '\x07', '\x6d', '\x65', '\x74', '\x61',
+						'\x64', '\x61', '\x74', '\x61', '\x00', '\x5c', '\x11', '\x51',
+						'\x56', '\xc9', '\x75', '\x50', '\x47', '\xe3', '\x18', '\xbb',
+						'\xfd', '\x00',
+					},
+					count: 1,
+				},
+			},
+			expectedError: "Did not find any objects with tag",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"tag":  "",
+			},
+			expectedError: "Missing collection or tag name",
+			mockColl:      &mockCollection{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			m, _ := NewMongoStore("name", &mongo.Database{})
+			// Override the getCollection function with our mocked version
+			getCollection = func(coll string, m *MongoStore) MongoCollection {
+				return testCase.mockColl
+			}
+
+			decodeBytes = func(sr *mongo.SingleResult) (bson.Raw, error) {
+				return testCase.mockColl.mCursor.DecodeBytes()
+			}
+
+			got, err := m.ReadAll(testCase.input["coll"].(string), testCase.input["tag"].(string))
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Readall method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Readall method returned an error (%s)", err)
+				}
+			} else {
+				if reflect.DeepEqual(got, testCase.expected) == false {
+					t.Fatalf("Readall returned unexpected data: %v, expected: %v",
+						got, testCase.expected)
+				}
+			}
+		})
+	}
+}
diff --git a/src/k8splugin/db/store.go b/src/k8splugin/db/store.go
index c1a8b31f..a235597a 100644
--- a/src/k8splugin/db/store.go
+++ b/src/k8splugin/db/store.go
@@ -25,21 +25,38 @@ var DBconn Store
 
 // Store is an interface for accessing a database
 type Store interface {
+	// Returns nil if db health is good
 	HealthCheck() error
 
-	Create(string, string) error
-	Read(string) (string, error)
-	// Update(string) (string, error)
-	Delete(string) error
+	// Unmarshal implements any unmarshaling needed for the database
+	Unmarshal(inp []byte, out interface{}) error
 
-	ReadAll(string) ([]string, error)
+	// Creates a new master table with key and links data with tag and
+	// creates a pointer to the newly added data in the master table
+	Create(table, key, tag string, data interface{}) error
+
+	// Reads data for a particular key with specific tag.
+	Read(table, key, tag string) ([]byte, error)
+
+	//TODO: Update(context.Context, string, interface{}) error
+
+	// Deletes a specific tag data for key.
+	// TODO: If tag is empty, it will delete all tags under key.
+	Delete(table, key, tag string) error
+
+	// Reads all master tables and data from the specified tag in table
+	ReadAll(table, tag string) (map[string][]byte, error)
 }
 
 // CreateDBClient creates the DB client
 func CreateDBClient(dbType string) error {
 	var err error
 	switch dbType {
+	case "mongo":
+		// create a mongodb database with k8splugin as the name
+		DBconn, err = NewMongoStore("k8splugin", nil)
 	case "consul":
+		// create a consul kv store
 		DBconn, err = NewConsulStore(nil)
 	default:
 		return pkgerrors.New(dbType + "DB not supported")
diff --git a/src/k8splugin/db/store_test.go b/src/k8splugin/db/store_test.go
index 9bbe4a92..eed7065f 100644
--- a/src/k8splugin/db/store_test.go
+++ b/src/k8splugin/db/store_test.go
@@ -23,9 +23,9 @@ import (
 
 func TestCreateDBClient(t *testing.T) {
 	t.Run("Successfully create DB client", func(t *testing.T) {
-		expected := &ConsulStore{}
+		expected := &MongoStore{}
 
-		err := CreateDBClient("consul")
+		err := CreateDBClient("mongo")
 		if err != nil {
 			t.Fatalf("CreateDBClient returned an error (%s)", err)
 		}
diff --git a/src/k8splugin/db/testing.go b/src/k8splugin/db/testing.go
index 672fcbfb..4b7e6078 100644
--- a/src/k8splugin/db/testing.go
+++ b/src/k8splugin/db/testing.go
@@ -16,7 +16,8 @@ limitations under the License.
 package db
 
 import (
-	"github.com/hashicorp/consul/api"
+	"encoding/json"
+	pkgerrors "github.com/pkg/errors"
 )
 
 //Creating an embedded interface via anonymous variable
@@ -24,42 +25,45 @@ import (
 //interface even if we are not implementing all the methods in it
 type MockDB struct {
 	Store
-	Items api.KVPairs
+	Items map[string][]byte
 	Err   error
 }
 
-func (m *MockDB) Create(key string, value string) error {
+func (m *MockDB) Create(table, key, tag string, data interface{}) error {
 	return m.Err
 }
 
-func (m *MockDB) Read(key string) (string, error) {
+// MockDB uses simple JSON and not BSON
+func (m *MockDB) Unmarshal(inp []byte, out interface{}) error {
+	err := json.Unmarshal(inp, out)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Unmarshaling json")
+	}
+	return nil
+}
+
+func (m *MockDB) Read(table, key, tag string) ([]byte, error) {
 	if m.Err != nil {
-		return "", m.Err
+		return nil, m.Err
 	}
 
-	for _, kvpair := range m.Items {
-		if kvpair.Key == key {
-			return string(kvpair.Value), nil
+	for k, v := range m.Items {
+		if k == key {
+			return v, nil
 		}
 	}
 
-	return "", nil
+	return nil, m.Err
 }
 
-func (m *MockDB) Delete(key string) error {
+func (m *MockDB) Delete(table, key, tag string) error {
 	return m.Err
 }
 
-func (m *MockDB) ReadAll(prefix string) ([]string, error) {
+func (m *MockDB) ReadAll(table, tag string) (map[string][]byte, error) {
 	if m.Err != nil {
-		return []string{}, m.Err
-	}
-
-	var res []string
-
-	for _, keypair := range m.Items {
-		res = append(res, keypair.Key)
+		return nil, m.Err
 	}
 
-	return res, nil
+	return m.Items, nil
 }