Restructure code and create module library

Restructures and moves code to make it
aligned with the current design.
https://wiki.onap.org/display/DW/Multi+Cluster+Application+Scheduler
examples/example_module.go shows how to
import and use modules from this package.
Patch#2 Updated example

Issue-ID: MULTICLOUD-871
Signed-off-by: Ritu Sood <ritu.sood@intel.com>
Change-Id: Ia1e9802a946a07dcca8f79f0e2250933ab3efa66

6 files changed, 1437 insertions, 0 deletions

diff --git a/src/orchestrator/pkg/infra/db/README.md b/src/orchestrator/pkg/infra/db/README.md
new file mode 100644
index 00000000..cba1b7ea
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/README.md
@@ -0,0 +1,123 @@
+# Database Abstraction Layer
+
+This package contains implementations of the Database interface defined in `store.go`
+Any database can be used as the backend as long as the following interface is implemented;
+
+```go
+type Store interface {
+	// Returns nil if db health is good
+	HealthCheck() error
+
+	// Unmarshal implements any unmarshaling needed for the database
+	Unmarshal(inp []byte, out interface{}) 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 string, key Key, tag string, data interface{}) error
+
+	// Reads data for a particular key with specific tag.
+	Read(table string, key Key, tag string) ([]byte, error)
+
+	// Update data for particular key with specific tag
+	Update(table string, key Key, tag string, data interface{}) error
+
+	// Deletes a specific tag data for key.
+	// TODO: If tag is empty, it will delete all tags under key.
+	Delete(table string, key Key, tag string) error
+
+	// Reads all master tables and data from the specified tag in table
+	ReadAll(table string, tag string) (map[string][]byte, error)
+}
+```
+
+Therefore, `mongo.go`, `consul.go` implement the above interface and can be used as the backend as needed based on initial configuration.
+
+## Details on Mongo Implementation
+
+`mongo.go` implements the above interface using the `go.mongodb.org/mongo-driver` package.
+The code converts incoming binary data and creates a new document in the database.
+
+### Create
+
+Arguments:
+```go
+collection string
+key interface
+tag string
+data []byte
+```
+
+Create inserts the provided `data` into the `collection` which returns an auto-generated (by `mongodb`) ID which we then associate with the `key` that is provided as one of the arguments.
+
+We use the `FindOneAndUpdate` mongo API to achieve this with the `upsert` option set to `true`.
+We create the following documents in mongodb for each new definition added to the database:
+
+There is a Master Key document that contains references to other documents which are related to this `key`.
+
+#### Master Key Entry
+```json
+{
+    "_id" : ObjectId("5e0a8554b78a15f71d2dce7e"),
+    "key" : { "rbname" : "edgex", "rbversion" : "v1"},
+    "defmetadata" : ObjectId("5e0a8554be261ecb57f067eb"),
+    "defcontent" : ObjectId("5e0a8377bcfcdd0f01dc7b0d")
+}
+```
+#### Metadata Key Entry
+```json
+{
+    "_id" : ObjectId("5e0a8554be261ecb57f067eb"),
+    "defmetadata" : { "rbname" : "edgex", "rbversion" : "v1", "chartname" : "", "description" : "", "labels" : null }
+}
+```
+#### Definition Content
+```json
+{
+    "_id" : ObjectId("5e0a8377bcfcdd0f01dc7b0d"),
+    "defcontent" : "H4sICCVd3FwAA3Byb2ZpbGUxLnRhcgDt1NEKgjAUxvFd7ylG98aWOsGXiYELxLRwJvj2rbyoIPDGiuD/uzmwM9iB7Vvruvrgw7CdXHsUn6Ejm2W3aopcP9eZLYRJM1voPN+ZndAm16kVSn9onheXMLheKeGqfdM0rq07/3bfUv9PJUkiR9+H+tSVajRymM6+lEqN7njxoVSbU+z2deX388r9nWzkr8fGSt5d79pnLOZfm0f+dRrzb7P4DZD/LyDJAAAAAAAAAAAAAAAA/+0Ksq1N5QAoAAA="
+}
+```
+
+### Unmarshal
+
+Data in mongo is stored as `bson` which is a compressed form of `json`. We need mongo to convert the stored `bson` data to regular `json`
+that we can use in our code when returned.
+
+We just use the `bson.Unmarshal` API to achieve this.
+
+### Read
+
+Arguments:
+```go
+collection string
+key interface
+tag string
+```
+
+Read is straight forward and it uses the `FindOne` API to find our Mongo document based on the provided `key` and then gets the corresponding data for the given `tag`. It will return []byte which can then be passed to the `Unmarshal` function to get the desired GO object.
+
+### Delete
+
+Delete is similar to Read and deletes all the objectIDs being stored for a given `key` in the collection.
+
+## Testing Interfaces
+
+The following interface exists to allow for the development of unit tests which don't require mongo to be running.
+It is mentioned so in the code as well.
+
+```go
+// 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)
+}
+```
\ No newline at end of file
diff --git a/src/orchestrator/pkg/infra/db/mock.go b/src/orchestrator/pkg/infra/db/mock.go
new file mode 100644
index 00000000..1dbca4b4
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/mock.go
@@ -0,0 +1,94 @@
+/*
+Copyright 2018 Intel Corporation.
+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 (
+	"encoding/json"
+
+	pkgerrors "github.com/pkg/errors"
+)
+
+type MockKey struct {
+	Key string
+}
+
+func (m MockKey) String() string {
+	return m.Key
+}
+
+//Creating an embedded interface via anonymous variable
+//This allows us to make mockDB satisfy the DatabaseConnection
+//interface even if we are not implementing all the methods in it
+type MockDB struct {
+	Store
+	Items map[string]map[string][]byte
+	Err   error
+}
+
+func (m *MockDB) HealthCheck() error {
+	return m.Err
+}
+
+func (m *MockDB) Create(table string, key Key, tag string, data interface{}) error {
+	return m.Err
+}
+
+func (m *MockDB) Update(table string, key Key, tag string, data interface{}) error {
+	return m.Err
+}
+
+// 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 string, key Key, tag string) ([]byte, error) {
+	if m.Err != nil {
+		return nil, m.Err
+	}
+
+	for k, v := range m.Items {
+		if k == key.String() {
+			return v[tag], nil
+		}
+	}
+
+	return nil, m.Err
+}
+
+func (m *MockDB) Delete(table string, key Key, tag string) error {
+	return m.Err
+}
+
+func (m *MockDB) ReadAll(table string, tag string) (map[string][]byte, error) {
+	if m.Err != nil {
+		return nil, m.Err
+	}
+
+	ret := make(map[string][]byte)
+
+	for k, v := range m.Items {
+		for k1, v1 := range v {
+			if k1 == tag {
+				ret[k] = v1
+			}
+		}
+	}
+
+	return ret, nil
+}
diff --git a/src/orchestrator/pkg/infra/db/mongo.go b/src/orchestrator/pkg/infra/db/mongo.go
new file mode 100644
index 00000000..32d0b549
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/mongo.go
@@ -0,0 +1,396 @@
+/*
+ * 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 (
+	"log"
+
+	"golang.org/x/net/context"
+
+	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/config"
+
+	pkgerrors "github.com/pkg/errors"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/primitive"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+// 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()
+}
+
+// These exists only for allowing us to mock the cursor.Next function
+// Mainly because we cannot construct a mongo.Cursor struct from our
+// tests. All fields in that struct are private and there is no public
+// constructor method.
+var cursorNext = func(ctx context.Context, cursor *mongo.Cursor) bool {
+	return cursor.Next(ctx)
+}
+var cursorClose = func(ctx context.Context, cursor *mongo.Cursor) error {
+	return cursor.Close(ctx)
+}
+
+// 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://" + config.GetConfiguration().DatabaseIP + ":27017"
+		clientOptions := options.Client()
+		clientOptions.ApplyURI(ip)
+		mongoClient, err := mongo.NewClient(clientOptions)
+		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 ...interface{}) bool {
+	for _, v := range args {
+		val, ok := v.(string)
+		if ok {
+			if val == "" {
+				return false
+			}
+		} else {
+			if v == nil {
+				return false
+			}
+		}
+	}
+
+	return true
+}
+
+// Create is used to create a DB entry
+func (m *MongoStore) Create(coll string, key 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{
+				{"$set", bson.D{
+					{tag, res.InsertedID},
+				}},
+			},
+			options.FindOneAndUpdate().SetUpsert(true).SetReturnDocument(options.After)))
+
+	if err != nil {
+		return pkgerrors.Errorf("Error updating master table: %s", err.Error())
+	}
+
+	return nil
+}
+
+// Update is used to update a DB entry
+func (m *MongoStore) Update(coll string, key Key, tag string, data interface{}) error {
+	if data == nil || !m.validateParams(coll, key, tag) {
+		return pkgerrors.New("No Data to update")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Get the masterkey document based on given key
+	filter := bson.D{{"key", key}}
+	keydata, err := decodeBytes(c.FindOne(context.Background(), filter))
+	if err != nil {
+		return pkgerrors.Errorf("Error finding master table: %s", err.Error())
+	}
+
+	//Read the tag objectID from document
+	tagoid, ok := keydata.Lookup(tag).ObjectIDOK()
+	if !ok {
+		return pkgerrors.Errorf("Error finding objectID for tag %s", tag)
+	}
+
+	//Update the document with new data
+	filter = bson.D{{"_id", tagoid}}
+
+	_, err = decodeBytes(
+		c.FindOneAndUpdate(
+			ctx,
+			filter,
+			bson.D{
+				{"$set", bson.D{
+					{tag, data},
+				}},
+			},
+			options.FindOneAndUpdate().SetReturnDocument(options.After)))
+
+	if err != nil {
+		return pkgerrors.Errorf("Error updating record: %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 string, key 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
+	//Convert string data to byte array using the built-in functions
+	switch tagdata.Lookup(tag).Type {
+	case bson.TypeString:
+		return []byte(tagdata.Lookup(tag).StringValue()), nil
+	default:
+		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 string, key 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{
+		{
+			"$unset", bson.D{
+				{tag, ""},
+			},
+		},
+	}
+	keydata, err := decodeBytes(c.FindOneAndUpdate(ctx, filter, update,
+		options.FindOneAndUpdate().SetReturnDocument(options.Before)))
+	if err != nil {
+		//No document was found. Return nil.
+		if err == mongo.ErrNoDocuments {
+			return nil
+		}
+		//Return any other error that was found.
+		return pkgerrors.Errorf("Error decoding master table after update: %s",
+			err.Error())
+	}
+
+	//Read the tag objectID from document
+	elems, err := keydata.Elements()
+	if err != nil {
+		return pkgerrors.Errorf("Error reading elements from database: %s", err.Error())
+	}
+
+	tagoid, ok := keydata.Lookup(tag).ObjectIDOK()
+	if !ok {
+		return pkgerrors.Errorf("Error finding objectID for tag %s", tag)
+	}
+
+	//Use tag objectID to read the data from store
+	err = m.deleteObjectByID(coll, tagoid)
+	if err != nil {
+		return pkgerrors.Errorf("Error deleting from database: %s", err.Error())
+	}
+
+	//Delete master table if no more tags left
+	//_id, key and tag should be elements in before doc
+	//if master table needs to be removed too
+	if len(elems) == 3 {
+		keyid, ok := keydata.Lookup("_id").ObjectIDOK()
+		if !ok {
+			return pkgerrors.Errorf("Error finding objectID for key %s", key)
+		}
+		err = m.deleteObjectByID(coll, keyid)
+		if err != nil {
+			return pkgerrors.Errorf("Error deleting master table from database: %s", err.Error())
+		}
+	}
+
+	return nil
+}
+
+// ReadAll is used to get all documents in db of a particular tag
+func (m *MongoStore) ReadAll(coll, tag string) (map[string][]byte, error) {
+	if !m.validateParams(coll, tag) {
+		return nil, pkgerrors.New("Missing collection or tag name")
+	}
+
+	c := getCollection(coll, m)
+	ctx := context.Background()
+
+	//Get all master tables in this collection
+	filter := bson.D{
+		{"key", bson.D{
+			{"$exists", true},
+		}},
+	}
+	cursor, err := c.Find(ctx, filter)
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error reading from database: %s", err.Error())
+	}
+	defer cursorClose(ctx, cursor)
+
+	//Iterate over all the master tables
+	result := make(map[string][]byte)
+	for cursorNext(ctx, cursor) {
+		d := cursor.Current
+
+		//Read key of each master table
+		key, ok := d.Lookup("key").DocumentOK()
+		if !ok {
+			//Throw error if key is not found
+			pkgerrors.New("Unable to read key from mastertable")
+		}
+
+		//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.String()] = 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/orchestrator/pkg/infra/db/mongo_test.go b/src/orchestrator/pkg/infra/db/mongo_test.go
new file mode 100644
index 00000000..171c908f
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/mongo_test.go
@@ -0,0 +1,597 @@
+/*
+ * 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"
+	"reflect"
+	"strings"
+	"testing"
+
+	pkgerrors "github.com/pkg/errors"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+//Implements the functions used currently in mongo.go
+type mockCollection struct {
+	Err          error
+	mCursor      *mongo.Cursor
+	mCursorCount int
+}
+
+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":  MockKey{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":  MockKey{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":  MockKey{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"].(Key),
+				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 TestUpdate(t *testing.T) {
+	testCases := []struct {
+		label         string
+		input         map[string]interface{}
+		mockColl      *mockCollection
+		bson          bson.Raw
+		expectedError string
+	}{
+		{
+			label: "Successfull update of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  MockKey{Key: "keyvalue"},
+				"tag":  "metadata",
+				"data": "Data In String Format",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+				'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+				'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+				'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+				'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+				'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+				'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+				'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+				'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+				'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+				'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+			},
+			mockColl: &mockCollection{},
+		},
+		{
+			label: "Entry does not exist",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  MockKey{Key: "keyvalue"},
+				"tag":  "tagName",
+				"data": "Data In String Format",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+	}
+
+	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.Update(testCase.input["coll"].(string), testCase.input["key"].(Key),
+				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":  MockKey{Key: "keyvalue"},
+				"tag":  "metadata",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+				'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+				'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+				'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+				'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+				'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+				'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+				'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+				'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+				'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+				'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+			},
+			mockColl: &mockCollection{},
+			// This is not the document because we are mocking decodeBytes
+			expected: []byte{92, 17, 81, 86, 119, 127, 248, 86, 84, 36, 138, 225},
+		},
+		{
+			label: "UnSuccessfull Read of entry: object not found",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  MockKey{Key: "keyvalue"},
+				"tag":  "badtag",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+				'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+				'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+				'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+				'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+				'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+				'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+				'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+				'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+				'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+				'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+			},
+			mockColl:      &mockCollection{},
+			expectedError: "Error finding objectID",
+		},
+		{
+			label: "UnSuccessfull Read of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  MockKey{Key: "keyvalue"},
+				"tag":  "tagName",
+			},
+			mockColl: &mockCollection{
+				Err: pkgerrors.New("DB Error"),
+			},
+			expectedError: "DB Error",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"key":  MockKey{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"].(Key),
+				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: %v, expected: %v",
+						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":  MockKey{Key: "keyvalue"},
+				"tag":  "metadata",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+				'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+				'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+				'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+				'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+				'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+				'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+				'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+				'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+				'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+				'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+			},
+			mockColl: &mockCollection{},
+		},
+		{
+			label: "UnSuccessfull Delete of entry",
+			input: map[string]interface{}{
+				"coll": "collname",
+				"key":  MockKey{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":  MockKey{Key: "keyvalue"},
+				"tag":  "tagName",
+			},
+			// Binary form of
+			// {
+			//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+			//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+			//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+			// }
+			bson: bson.Raw{
+				'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+				'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+				'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+				'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+				'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+				'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+				'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+				'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+				'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+				'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+				'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+			},
+			mockColl:      &mockCollection{},
+			expectedError: "Error finding objectID",
+		},
+		{
+			label: "Missing input fields",
+			input: map[string]interface{}{
+				"coll": "",
+				"key":  MockKey{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"].(Key),
+				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: &mongo.Cursor{
+					// Binary form of
+					// {
+					//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+					//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+					//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+					// }
+
+					Current: bson.Raw{
+						'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+						'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+						'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+						'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+						'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+						'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+						'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+						'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+						'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+						'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+						'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+					},
+				},
+				mCursorCount: 1,
+			},
+			expected: map[string][]byte{
+				`{"name": "testdef","version": "v1"}`: []byte{
+					92, 17, 81, 86, 119, 127, 248, 86, 84, 36, 138, 225},
+			},
+		},
+		{
+			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: &mongo.Cursor{
+					// Binary form of
+					// {
+					//	"_id" : ObjectId("5c115156777ff85654248ae1"),
+					//  "key" : bson.D{{"name","testdef"},{"version","v1"}},
+					//  "metadata" : ObjectId("5c115156c9755047e318bbfd")
+					// }
+					Current: bson.Raw{
+						'\x58', '\x00', '\x00', '\x00', '\x03', '\x6b', '\x65', '\x79',
+						'\x00', '\x27', '\x00', '\x00', '\x00', '\x02', '\x6e', '\x61',
+						'\x6d', '\x65', '\x00', '\x08', '\x00', '\x00', '\x00', '\x74',
+						'\x65', '\x73', '\x74', '\x64', '\x65', '\x66', '\x00', '\x02',
+						'\x76', '\x65', '\x72', '\x73', '\x69', '\x6f', '\x6e', '\x00',
+						'\x03', '\x00', '\x00', '\x00', '\x76', '\x31', '\x00', '\x00',
+						'\x07', '\x6d', '\x65', '\x74', '\x61', '\x64', '\x61', '\x74',
+						'\x61', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77', '\x7f',
+						'\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x07', '\x5f',
+						'\x69', '\x64', '\x00', '\x5c', '\x11', '\x51', '\x56', '\x77',
+						'\x7f', '\xf8', '\x56', '\x54', '\x24', '\x8a', '\xe1', '\x00',
+					},
+				},
+				mCursorCount: 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.Current, testCase.mockColl.Err
+			}
+
+			cursorNext = func(ctx context.Context, cursor *mongo.Cursor) bool {
+				if testCase.mockColl.mCursorCount > 0 {
+					testCase.mockColl.mCursorCount -= 1
+					return true
+				}
+				return false
+			}
+
+			cursorClose = func(ctx context.Context, cursor *mongo.Cursor) error {
+				return nil
+			}
+
+			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/orchestrator/pkg/infra/db/store.go b/src/orchestrator/pkg/infra/db/store.go
new file mode 100644
index 00000000..1a9632e7
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/store.go
@@ -0,0 +1,106 @@
+/*
+Copyright 2018 Intel Corporation.
+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 (
+	"encoding/json"
+	"reflect"
+
+	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/config"
+
+	pkgerrors "github.com/pkg/errors"
+)
+
+// DBconn interface used to talk a concrete Database connection
+var DBconn Store
+
+// Key is an interface that will be implemented by anypackage
+// that wants to use the Store interface. This allows various
+// db backends and key types.
+type Key interface {
+	String() string
+}
+
+// Store is an interface for accessing the database
+type Store interface {
+	// Returns nil if db health is good
+	HealthCheck() error
+
+	// Unmarshal implements any unmarshaling needed for the database
+	Unmarshal(inp []byte, out interface{}) error
+
+	// Creates a new master document with key and links data with tag and
+	// creates a pointer(row) to the newly added data in the master table
+	Create(table string, key Key, tag string, data interface{}) error
+
+	// Reads data for a particular key with specific tag.
+	Read(table string, key Key, tag string) ([]byte, error)
+
+	// Update data for particular key with specific tag
+	Update(table string, key Key, tag string, data interface{}) error
+
+	// Deletes a specific tag data for key.
+	// TODO: If tag is empty, it will delete all tags under key.
+	Delete(table string, key Key, tag string) error
+
+	// Reads all master tables and data from the specified tag in table
+	ReadAll(table string, 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 orchestrator as the name
+		DBconn, err = NewMongoStore("orchestrator", nil)
+	default:
+		return pkgerrors.New(dbType + "DB not supported")
+	}
+	return err
+}
+
+// Serialize converts given data into a JSON string
+func Serialize(v interface{}) (string, error) {
+	out, err := json.Marshal(v)
+	if err != nil {
+		return "", pkgerrors.Wrap(err, "Error serializing "+reflect.TypeOf(v).String())
+	}
+	return string(out), nil
+}
+
+// DeSerialize converts string to a json object specified by type
+func DeSerialize(str string, v interface{}) error {
+	err := json.Unmarshal([]byte(str), &v)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Error deSerializing "+str)
+	}
+	return nil
+}
+
+// InitializeDatabaseConnection sets up the connection to the
+// configured database to allow the application to talk to it.
+func InitializeDatabaseConnection() error {
+	err := createDBClient(config.GetConfiguration().DatabaseType)
+	if err != nil {
+		return pkgerrors.Cause(err)
+	}
+
+	err = DBconn.HealthCheck()
+	if err != nil {
+		return pkgerrors.Cause(err)
+	}
+
+	return nil
+}
diff --git a/src/orchestrator/pkg/infra/db/store_test.go b/src/orchestrator/pkg/infra/db/store_test.go
new file mode 100644
index 00000000..42a41787
--- /dev/null
+++ b/src/orchestrator/pkg/infra/db/store_test.go
@@ -0,0 +1,121 @@
+/*
+Copyright 2018 Intel Corporation.
+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 (
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestCreateDBClient(t *testing.T) {
+	t.Run("Successfully create DB client", func(t *testing.T) {
+		expected := &MongoStore{}
+
+		err := createDBClient("mongo")
+		if err != nil {
+			t.Fatalf("CreateDBClient returned an error (%s)", err)
+		}
+		if reflect.TypeOf(DBconn) != reflect.TypeOf(expected) {
+			t.Fatalf("CreateDBClient set DBconn as:\n result=%T\n expected=%T", DBconn, expected)
+		}
+	})
+	t.Run("Fail to create client for unsupported DB", func(t *testing.T) {
+		err := createDBClient("fakeDB")
+		if err == nil {
+			t.Fatal("CreateDBClient didn't return an error")
+		}
+		if !strings.Contains(string(err.Error()), "DB not supported") {
+			t.Fatalf("CreateDBClient method returned an error (%s)", err)
+		}
+	})
+}
+
+func TestSerialize(t *testing.T) {
+
+	inp := map[string]interface{}{
+		"UUID":   "123e4567-e89b-12d3-a456-426655440000",
+		"Data":   "sdaijsdiodalkfjsdlagf",
+		"Number": 23,
+		"Float":  34.4,
+		"Map": map[string]interface{}{
+			"m1": "m1",
+			"m2": 2,
+			"m3": 3.0,
+		},
+	}
+
+	got, err := Serialize(inp)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := "{\"Data\":\"sdaijsdiodalkfjsdlagf\"," +
+		"\"Float\":34.4,\"Map\":{\"m1\":\"m1\",\"m2\":2,\"m3\":3}," +
+		"\"Number\":23,\"UUID\":\"123e4567-e89b-12d3-a456-426655440000\"}"
+
+	if expected != got {
+		t.Errorf("Serialize returned unexpected string: %s;"+
+			" expected %sv", got, expected)
+	}
+}
+
+func TestDeSerialize(t *testing.T) {
+	testCases := []struct {
+		label    string
+		input    string
+		expected map[string]interface{}
+		errMsg   string
+	}{
+		{
+			label: "Sucessful deserialize entry",
+			input: "{\"Data\":\"sdaijsdiodalkfjsdlagf\"," +
+				"\"Float\":34.4,\"Map\":{\"m1\":\"m1\",\"m3\":3}," +
+				"\"UUID\":\"123e4567-e89b-12d3-a456-426655440000\"}",
+			expected: map[string]interface{}{
+				"UUID":  "123e4567-e89b-12d3-a456-426655440000",
+				"Data":  "sdaijsdiodalkfjsdlagf",
+				"Float": 34.4,
+				"Map": map[string]interface{}{
+					"m1": "m1",
+					"m3": 3.0,
+				},
+			},
+		},
+		{
+			label:  "Fail to deserialize invalid entry",
+			input:  "{invalid}",
+			errMsg: "Error deSerializing {invalid}: invalid character 'i' looking for beginning of object key string",
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			got := make(map[string]interface{})
+			err := DeSerialize(testCase.input, &got)
+			if err != nil {
+				if testCase.errMsg == "" {
+					t.Fatalf("DeSerialize method return an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.errMsg) {
+					t.Fatalf("DeSerialize method returned an error (%s)", err)
+				}
+			} else {
+				if !reflect.DeepEqual(testCase.expected, got) {
+					t.Errorf("Serialize returned unexpected : %v;"+
+						" expected %v", got, testCase.expected)
+				}
+			}
+		})
+	}
+}