Add etcd support in infrastructure layer

Create a etcd client and provide minimal
functionality needed by the orchestrator
for using etcd

Issue-ID: MULTICLOUD-871
Signed-off-by: Ritu Sood <ritu.sood@intel.com>
Change-Id: I56fb4643addf43cdc59366e7163b66bb1618876d

5 files changed, 588 insertions, 1 deletions

diff --git a/src/orchestrator/cmd/main.go b/src/orchestrator/cmd/main.go
index fb8f26d6..f46fe910 100644
--- a/src/orchestrator/cmd/main.go
+++ b/src/orchestrator/cmd/main.go
@@ -26,7 +26,7 @@ import (
 	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/auth"
 	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/config"
 	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/db"
-
+	contextDb "github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/contextdb"
 	"github.com/gorilla/handlers"
 )
 
@@ -40,6 +40,12 @@ func main() {
 		log.Println(err)
 		log.Fatalln("Exiting...")
 	}
+        err = contextDb.InitializeContextDatabase()
+	if err != nil {
+		log.Println("Unable to initialize database connection...")
+		log.Println(err)
+		log.Fatalln("Exiting...")
+	}
 
 	httpRouter := api.NewRouter(nil)
 	loggedRouter := handlers.LoggingHandler(os.Stdout, httpRouter)
diff --git a/src/orchestrator/pkg/infra/contextdb/contextdb.go b/src/orchestrator/pkg/infra/contextdb/contextdb.go
new file mode 100644
index 00000000..d18af227
--- /dev/null
+++ b/src/orchestrator/pkg/infra/contextdb/contextdb.go
@@ -0,0 +1,72 @@
+/*
+Copyright 2020 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 contextdb
+
+import (
+	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/config"
+	pkgerrors "github.com/pkg/errors"
+)
+
+// Db interface used to talk a concrete Database connection
+var Db ContextDb
+
+// ContextDb is an interface for accessing the context database
+type ContextDb interface {
+	// Returns nil if db health is good
+	HealthCheck() error
+	// Puts Json Struct in db with key
+	Put(key string, value interface{}) error
+	// Delete k,v
+	Delete(key string) error
+	// Gets Json Struct from db
+	Get(key string, value interface{}) error
+	// Returns all keys with a prefix
+	GetAllKeys(path string) ([]string, error)
+}
+
+// createContextDBClient creates the DB client
+func createContextDBClient(dbType string) error {
+	var err error
+	switch dbType {
+	case "etcd":
+		c := EtcdConfig{
+			Endpoint: config.GetConfiguration().EtcdIP,
+			CertFile: config.GetConfiguration().EtcdCert,
+			KeyFile:  config.GetConfiguration().EtcdKey,
+			CAFile:   config.GetConfiguration().EtcdCAFile,
+		}
+		Db, err = NewEtcdClient(nil, c)
+		if err != nil {
+			pkgerrors.Wrap(err, "Etcd Client Initialization failed with error")
+		}
+	default:
+		return pkgerrors.New(dbType + "DB not supported")
+	}
+	return err
+}
+
+// InitializeContextDatabase sets up the connection to the
+// configured database to allow the application to talk to it.
+func InitializeContextDatabase() error {
+	// Only support Etcd for now
+	err := createContextDBClient("etcd")
+	if err != nil {
+		return pkgerrors.Cause(err)
+	}
+	err = Db.HealthCheck()
+	if err != nil {
+		return pkgerrors.Cause(err)
+	}
+	return nil
+}
diff --git a/src/orchestrator/pkg/infra/contextdb/etcd.go b/src/orchestrator/pkg/infra/contextdb/etcd.go
new file mode 100644
index 00000000..a1922d3b
--- /dev/null
+++ b/src/orchestrator/pkg/infra/contextdb/etcd.go
@@ -0,0 +1,175 @@
+/*
+ * Copyright 2020 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 contextdb
+
+import (
+	"context"
+	"encoding/json"
+	pkgerrors "github.com/pkg/errors"
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/pkg/transport"
+	"time"
+)
+
+// EtcdConfig Configuration values needed for Etcd Client
+type EtcdConfig struct {
+	Endpoint string
+	CertFile string
+	KeyFile  string
+	CAFile   string
+}
+
+// EtcdClient for Etcd
+type EtcdClient struct {
+	cli      *clientv3.Client
+	endpoint string
+}
+
+// Etcd For Mocking purposes
+type Etcd interface {
+	Put(ctx context.Context, key, val string, opts ...clientv3.OpOption) (*clientv3.PutResponse, error)
+	Get(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.GetResponse, error)
+	Delete(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.DeleteResponse, error)
+}
+
+var getEtcd = func(e *EtcdClient) Etcd {
+	return e.cli
+}
+
+// NewEtcdClient function initializes Etcd client
+func NewEtcdClient(store *clientv3.Client, c EtcdConfig) (ContextDb, error) {
+	var endpoint string
+	if store == nil {
+		tlsInfo := transport.TLSInfo{
+			CertFile: c.CertFile,
+			KeyFile:  c.KeyFile,
+			CAFile:   c.CAFile,
+		}
+		tlsConfig, err := tlsInfo.ClientConfig()
+		if err != nil {
+			return nil, pkgerrors.Errorf("Error creating etcd TLSInfo: %s", err.Error())
+		}
+		// NOTE: Client relies on nil tlsConfig
+		// for non-secure connections, update the implicit variable
+		if len(c.CertFile) == 0 && len(c.KeyFile) == 0 && len(c.CAFile) == 0 {
+			tlsConfig = nil
+		}
+		endpoint = ""
+		if tlsConfig == nil {
+			endpoint = "http://" + c.Endpoint + ":2379"
+		} else {
+			endpoint = "https://" + c.Endpoint + ":2379"
+		}
+
+		store, err = clientv3.New(clientv3.Config{
+			Endpoints:   []string{endpoint},
+			DialTimeout: 5 * time.Second,
+			TLS:         tlsConfig,
+		})
+		if err != nil {
+			return nil, pkgerrors.Errorf("Error creating etcd client: %s", err.Error())
+		}
+	}
+
+	return &EtcdClient{
+		cli:      store,
+		endpoint: endpoint,
+	}, nil
+}
+
+// Put values in Etcd DB
+func (e *EtcdClient) Put(key string, value interface{}) error {
+	cli := getEtcd(e)
+	if cli == nil {
+		return pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	if key == "" {
+		return pkgerrors.Errorf("Key is null")
+	}
+	if value == nil {
+		return pkgerrors.Errorf("Value is nil")
+	}
+	v, err := json.Marshal(value)
+	if err != nil {
+		return pkgerrors.Errorf("Json Marshal error: %s", err.Error())
+	}
+	_, err = cli.Put(context.Background(), key, string(v))
+	if err != nil {
+		return pkgerrors.Errorf("Error creating etcd entry: %s", err.Error())
+	}
+	return nil
+}
+
+// Get values from Etcd DB and decodes from json
+func (e *EtcdClient) Get(key string, value interface{}) error {
+	cli := getEtcd(e)
+	if cli == nil {
+		return pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	if key == "" {
+		return pkgerrors.Errorf("Key is null")
+	}
+	if value == nil {
+		return pkgerrors.Errorf("Value is nil")
+	}
+	getResp, err := cli.Get(context.Background(), key)
+	if err != nil {
+		return pkgerrors.Errorf("Error getting etcd entry: %s", err.Error())
+	}
+	if getResp.Count == 0 {
+		return pkgerrors.Errorf("Key doesn't exist")
+	}
+	return json.Unmarshal(getResp.Kvs[0].Value, value)
+}
+
+// GetAllKeys values from Etcd DB
+func (e *EtcdClient) GetAllKeys(key string) ([]string, error) {
+	cli := getEtcd(e)
+	if cli == nil {
+		return nil, pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	getResp, err := cli.Get(context.Background(), key, clientv3.WithPrefix())
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error getting etcd entry: %s", err.Error())
+	}
+	if getResp.Count == 0 {
+		return nil, pkgerrors.Errorf("Key doesn't exist")
+	}
+	var keys []string
+	for _, ev := range getResp.Kvs {
+		keys = append(keys, string(ev.Key))
+	}
+	return keys, nil
+}
+
+// Delete values from Etcd DB
+func (e *EtcdClient) Delete(key string) error {
+	cli := getEtcd(e)
+	if cli == nil {
+		return pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	_, err := cli.Delete(context.Background(), key, clientv3.WithPrefix())
+	if err != nil {
+		return pkgerrors.Errorf("Delete failed etcd entry: %s", err.Error())
+	}
+	return nil
+}
+
+// HealthCheck for checking health of the etcd cluster
+func (e *EtcdClient) HealthCheck() error {
+	return nil
+}
diff --git a/src/orchestrator/pkg/infra/contextdb/etcd_test.go b/src/orchestrator/pkg/infra/contextdb/etcd_test.go
new file mode 100644
index 00000000..17b7a5d5
--- /dev/null
+++ b/src/orchestrator/pkg/infra/contextdb/etcd_test.go
@@ -0,0 +1,276 @@
+/*
+Copyright 2020 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 contextdb
+
+import (
+	"context"
+	mvccpb "github.com/coreos/etcd/mvcc/mvccpb"
+	pkgerrors "github.com/pkg/errors"
+	"go.etcd.io/etcd/clientv3"
+	"strings"
+	"testing"
+)
+
+type kv struct {
+	Key   []byte
+	Value []byte
+}
+
+// MockEtcdClient for mocking etcd
+type MockEtcdClient struct {
+	Kvs   []*mvccpb.KeyValue
+	Count int64
+	Err   error
+}
+
+// Mocking only Single Value
+// Put function
+func (e *MockEtcdClient) Put(ctx context.Context, key, val string, opts ...clientv3.OpOption) (*clientv3.PutResponse, error) {
+	var m mvccpb.KeyValue
+	m.Key = []byte(key)
+	m.Value = []byte(val)
+	e.Count = e.Count + 1
+	e.Kvs = append(e.Kvs, &m)
+	return &clientv3.PutResponse{}, e.Err
+}
+
+// Get function
+func (e *MockEtcdClient) Get(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.GetResponse, error) {
+	var g clientv3.GetResponse
+	g.Kvs = e.Kvs
+	g.Count = e.Count
+	return &g, e.Err
+}
+
+// Delete function
+func (e *MockEtcdClient) Delete(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.DeleteResponse, error) {
+	return &clientv3.DeleteResponse{}, e.Err
+}
+
+type testStruct struct {
+	Name string `json:"name"`
+	Num  int    `json:"num"`
+}
+
+// TestPut test Put
+func TestPut(t *testing.T) {
+	testCases := []struct {
+		label         string
+		mockEtcd      *MockEtcdClient
+		expectedError string
+		key           string
+		value         *testStruct
+	}{
+		{
+			label:    "Success Case",
+			mockEtcd: &MockEtcdClient{},
+			key:      "test1",
+			value:    &testStruct{Name: "test", Num: 5},
+		},
+		{
+			label:         "Key is null",
+			mockEtcd:      &MockEtcdClient{},
+			key:           "",
+			expectedError: "Key is null",
+		},
+		{
+			label:         "Value is nil",
+			mockEtcd:      &MockEtcdClient{},
+			key:           "test1",
+			value:         nil,
+			expectedError: "Value is nil",
+		},
+		{
+			label:         "Error creating etcd entry",
+			mockEtcd:      &MockEtcdClient{Err: pkgerrors.New("DB Error")},
+			key:           "test1",
+			value:         &testStruct{Name: "test", Num: 5},
+			expectedError: "Error creating etcd entry: DB Error",
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			cli, _ := NewEtcdClient(&clientv3.Client{}, EtcdConfig{})
+			getEtcd = func(e *EtcdClient) Etcd {
+				return testCase.mockEtcd
+			}
+			err := cli.Put(testCase.key, testCase.value)
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Method returned an error (%s)", err)
+				}
+			}
+
+		})
+	}
+}
+
+func TestGet(t *testing.T) {
+	testCases := []struct {
+		label         string
+		mockEtcd      *MockEtcdClient
+		expectedError string
+		key           string
+		value         *testStruct
+	}{
+		{
+			label:         "Key is null",
+			mockEtcd:      &MockEtcdClient{},
+			key:           "",
+			value:         nil,
+			expectedError: "Key is null",
+		},
+		{
+			label:         "Key doesn't exist",
+			mockEtcd:      &MockEtcdClient{},
+			key:           "test1",
+			value:         &testStruct{},
+			expectedError: "Key doesn't exist",
+		},
+		{
+			label:         "Error getting etcd entry",
+			mockEtcd:      &MockEtcdClient{Err: pkgerrors.New("DB Error")},
+			key:           "test1",
+			value:         &testStruct{},
+			expectedError: "Error getting etcd entry: DB Error",
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			cli, _ := NewEtcdClient(&clientv3.Client{}, EtcdConfig{})
+			getEtcd = func(e *EtcdClient) Etcd {
+				return testCase.mockEtcd
+			}
+			err := cli.Get(testCase.key, testCase.value)
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Method returned an error (%s)", err)
+				}
+			}
+
+		})
+	}
+}
+
+func TestGetString(t *testing.T) {
+	testCases := []struct {
+		label         string
+		mockEtcd      *MockEtcdClient
+		expectedError string
+		value         string
+	}{
+		{
+			label:    "Success Case",
+			mockEtcd: &MockEtcdClient{},
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			cli, _ := NewEtcdClient(&clientv3.Client{}, EtcdConfig{})
+			getEtcd = func(e *EtcdClient) Etcd {
+				return testCase.mockEtcd
+			}
+			err := cli.Put("test", "test1")
+			if err != nil {
+				t.Error("Test failed", err)
+			}
+			var s string
+			err = cli.Get("test", &s)
+			if err != nil {
+				t.Error("Test failed", err)
+			}
+			if "test1" != s {
+				t.Error("Get Failed")
+			}
+		})
+	}
+}
+
+func TestDelete(t *testing.T) {
+	testCases := []struct {
+		label         string
+		mockEtcd      *MockEtcdClient
+		expectedError string
+	}{
+		{
+			label:    "Success Case",
+			mockEtcd: &MockEtcdClient{},
+		},
+		{
+			label:         "Delete failed etcd entry",
+			mockEtcd:      &MockEtcdClient{Err: pkgerrors.New("DB Error")},
+			expectedError: "Delete failed etcd entry: DB Error",
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			cli, _ := NewEtcdClient(&clientv3.Client{}, EtcdConfig{})
+			getEtcd = func(e *EtcdClient) Etcd {
+				return testCase.mockEtcd
+			}
+			err := cli.Delete("test")
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Method returned an error (%s)", err)
+				}
+			}
+
+		})
+	}
+}
+
+func TestGetAll(t *testing.T) {
+	testCases := []struct {
+		label         string
+		mockEtcd      *MockEtcdClient
+		expectedError string
+	}{
+		{
+			label:         "Key doesn't exist",
+			mockEtcd:      &MockEtcdClient{},
+			expectedError: "Key doesn't exist",
+		},
+		{
+			label:         "Error getting etcd entry",
+			mockEtcd:      &MockEtcdClient{Err: pkgerrors.New("DB Error")},
+			expectedError: "Error getting etcd entry: DB Error",
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(testCase.label, func(t *testing.T) {
+			cli, _ := NewEtcdClient(&clientv3.Client{}, EtcdConfig{})
+			getEtcd = func(e *EtcdClient) Etcd {
+				return testCase.mockEtcd
+			}
+			_, err := cli.GetAllKeys("test")
+			if err != nil {
+				if testCase.expectedError == "" {
+					t.Fatalf("Method returned an un-expected (%s)", err)
+				}
+				if !strings.Contains(string(err.Error()), testCase.expectedError) {
+					t.Fatalf("Method returned an error (%s)", err)
+				}
+			}
+		})
+	}
+}
diff --git a/src/orchestrator/pkg/infra/contextdb/mock.go b/src/orchestrator/pkg/infra/contextdb/mock.go
new file mode 100644
index 00000000..fc0f8ff7
--- /dev/null
+++ b/src/orchestrator/pkg/infra/contextdb/mock.go
@@ -0,0 +1,58 @@
+/*
+Copyright 2020 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 contextdb
+
+import (
+	pkgerrors "github.com/pkg/errors"
+)
+
+type MockEtcd struct {
+	Items map[string]interface{}
+	Err   error
+}
+
+func (c *MockEtcd) Put(key string, value interface{}) error {
+	if c.Items == nil {
+		c.Items = make(map[string]interface{})
+	}
+	c.Items[key] = value
+	return c.Err
+}
+
+func (c *MockEtcd) Get(key string, value interface{}) error {
+	for kvKey, kvValue := range c.Items {
+		if kvKey == key {
+			value = kvValue
+			return nil
+		}
+	}
+	return pkgerrors.Errorf("Key doesn't exist")
+}
+
+func (c *MockEtcd) Delete(key string) error {
+	delete(c.Items, key)
+	return c.Err
+}
+
+func (c *MockEtcd) GetAllKeys(path string) ([]string, error) {
+	var keys []string
+	for k, _ := range c.Items {
+		keys = append(keys, string(k))
+	}
+	return keys, nil
+}
+
+func (e *MockEtcd) HealthCheck() error {
+	return nil
+}