Day 2 Configuration API's

This patch adds Configuration API's
https://wiki.onap.org/display/DW/MultiCloud+K8s-Plugin-service+API%27s

Change-Id: I52ebfc5aa980ec8af4a31569d569216e9a2a760c
Issue-ID: MULTICLOUD-464
Signed-off-by: rsood <ritu.sood@intel.com>

2 files changed, 176 insertions, 0 deletions

diff --git a/src/k8splugin/internal/db/etcd.go b/src/k8splugin/internal/db/etcd.go
new file mode 100644
index 00000000..fda44b2f
--- /dev/null
+++ b/src/k8splugin/internal/db/etcd.go
@@ -0,0 +1,131 @@
+/*
+ * 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 (
+	"context"
+	"time"
+
+	pkgerrors "github.com/pkg/errors"
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/pkg/transport"
+)
+
+// EtcdConfig Configuration values needed for Etcd Client
+type EtcdConfig struct {
+	Endpoint string
+	CertFile string
+	KeyFile  string
+	CAFile   string
+}
+
+// EtcdStore Interface needed for mocking
+type EtcdStore interface {
+	Get(key string) ([]byte, error)
+	Put(key, value string) error
+	Delete(key string) error
+}
+
+// EtcdClient for Etcd
+type EtcdClient struct {
+	cli *clientv3.Client
+}
+
+// Etcd handle for interface
+var Etcd EtcdStore
+
+// NewEtcdClient function initializes Etcd client
+func NewEtcdClient(store *clientv3.Client, c EtcdConfig) error {
+	var err error
+	Etcd, err = newClient(store, c)
+	return err
+}
+
+func newClient(store *clientv3.Client, c EtcdConfig) (EtcdClient, error) {
+	if store == nil {
+		tlsInfo := transport.TLSInfo{
+			CertFile: c.CertFile,
+			KeyFile:  c.KeyFile,
+			CAFile:   c.CAFile,
+		}
+		tlsConfig, err := tlsInfo.ClientConfig()
+		if err != nil {
+			return EtcdClient{}, 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 := "https://" + c.Endpoint + ":2379"
+
+		store, err = clientv3.New(clientv3.Config{
+			Endpoints:   []string{endpoint},
+			DialTimeout: 5 * time.Second,
+			TLS:         tlsConfig,
+		})
+		if err != nil {
+			return EtcdClient{}, pkgerrors.Errorf("Error creating etcd client: %s", err.Error())
+		}
+	}
+
+	return EtcdClient{
+		cli: store,
+	}, nil
+}
+
+// Put values in Etcd DB
+func (e EtcdClient) Put(key, value string) error {
+
+	if e.cli == nil {
+		return pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	_, err := e.cli.Put(context.Background(), key, value)
+	if err != nil {
+		return pkgerrors.Errorf("Error creating etcd entry: %s", err.Error())
+	}
+	return nil
+}
+
+// Get values from Etcd DB
+func (e EtcdClient) Get(key string) ([]byte, error) {
+
+	if e.cli == nil {
+		return nil, pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	getResp, err := e.cli.Get(context.Background(), key)
+	if err != nil {
+		return nil, pkgerrors.Errorf("Error getitng etcd entry: %s", err.Error())
+	}
+	if getResp.Count == 0 {
+		return nil, pkgerrors.Errorf("Key doesn't exist")
+	}
+	return getResp.Kvs[0].Value, nil
+}
+
+// Delete values from Etcd DB
+func (e EtcdClient) Delete(key string) error {
+
+	if e.cli == nil {
+		return pkgerrors.Errorf("Etcd Client not initialized")
+	}
+	_, err := e.cli.Delete(context.Background(), key)
+	if err != nil {
+		return pkgerrors.Errorf("Delete failed etcd entry:%s", err.Error())
+	}
+	return nil
+}
diff --git a/src/k8splugin/internal/db/etcd_testing.go b/src/k8splugin/internal/db/etcd_testing.go
new file mode 100644
index 00000000..12b17e33
--- /dev/null
+++ b/src/k8splugin/internal/db/etcd_testing.go
@@ -0,0 +1,45 @@
+/*
+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 (
+	pkgerrors "github.com/pkg/errors"
+)
+
+type MockEtcdClient struct {
+	Items map[string]string
+	Err   error
+}
+
+func (c *MockEtcdClient) Put(key, value string) error {
+	if c.Items == nil {
+		c.Items = make(map[string]string)
+	}
+	c.Items[key] = value
+	return c.Err
+}
+
+func (c *MockEtcdClient) Get(key string) ([]byte, error) {
+	for kvKey, kvValue := range c.Items {
+		if kvKey == key {
+			return []byte(kvValue), nil
+		}
+	}
+	return nil, pkgerrors.Errorf("Key doesn't exist")
+}
+
+func (c *MockEtcdClient) Delete(key string) error {
+	delete(c.Items, key)
+	return c.Err
+}