Seed code for k8s multicloud plugin

This patch provides the initial seed code for the multicloud Kubernetes
plugin and also provides the plugin feature to add new Kubernetes
kinds.

Change-Id: Ie5ee414656665070cde2834c4855ac2ebc179a9a
Issue-ID: MULTICLOUD-301
Signed-off-by: Shashank Kumar Shankar <shashank.kumar.shankar@intel.com>
Signed-off-by: Victor Morales <victor.morales@intel.com>

3 files changed, 194 insertions, 0 deletions

diff --git a/src/k8splugin/db/DB.go b/src/k8splugin/db/DB.go
new file mode 100644
index 00000000..c8895088
--- /dev/null
+++ b/src/k8splugin/db/DB.go
@@ -0,0 +1,42 @@
+/*
+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"
+)
+
+// DBconn interface used to talk a concrete Database connection
+var DBconn DatabaseConnection
+
+// DatabaseConnection is an interface for accessing a database
+type DatabaseConnection interface {
+	InitializeDatabase() error
+	CheckDatabase() error
+	CreateEntry(string, string) error
+	ReadEntry(string) (string, bool, error)
+	DeleteEntry(string) error
+	ReadAll(string) ([]string, error)
+}
+
+// CreateDBClient creates the DB client
+var CreateDBClient = func(dbType string) error {
+	switch dbType {
+	case "consul":
+		DBconn = &ConsulDB{}
+		return nil
+	default:
+		return pkgerrors.New(dbType + "DB not supported")
+	}
+}
diff --git a/src/k8splugin/db/consul.go b/src/k8splugin/db/consul.go
new file mode 100644
index 00000000..9ab0d826
--- /dev/null
+++ b/src/k8splugin/db/consul.go
@@ -0,0 +1,112 @@
+/*
+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 (
+	consulapi "github.com/hashicorp/consul/api"
+	pkgerrors "github.com/pkg/errors"
+	"os"
+)
+
+// ConsulDB is an implementation of the DatabaseConnection interface
+type ConsulDB struct {
+	consulClient *consulapi.Client
+}
+
+// InitializeDatabase initialized the initial steps
+func (c *ConsulDB) InitializeDatabase() error {
+	if os.Getenv("DATABASE_IP") == "" {
+		return pkgerrors.New("DATABASE_IP environment variable not set.")
+	}
+	config := consulapi.DefaultConfig()
+	config.Address = os.Getenv("DATABASE_IP") + ":8500"
+
+	client, err := consulapi.NewClient(config)
+	if err != nil {
+		return err
+	}
+	c.consulClient = client
+	return nil
+}
+
+// CheckDatabase checks if the database is running
+func (c *ConsulDB) CheckDatabase() error {
+	kv := c.consulClient.KV()
+	_, _, err := kv.Get("test", nil)
+	if err != nil {
+		return pkgerrors.New("[ERROR] Cannot talk to Datastore. Check if it is running/reachable.")
+	}
+	return nil
+}
+
+// CreateEntry is used to create a DB entry
+func (c *ConsulDB) CreateEntry(key string, value string) error {
+	kv := c.consulClient.KV()
+
+	p := &consulapi.KVPair{Key: key, Value: []byte(value)}
+
+	_, err := kv.Put(p, nil)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// ReadEntry returns the internalID for a particular externalID is present in a namespace
+func (c *ConsulDB) ReadEntry(key string) (string, bool, error) {
+
+	kv := c.consulClient.KV()
+
+	pair, _, err := kv.Get(key, nil)
+
+	if pair == nil {
+		return string("No value found for ID: " + key), false, err
+	}
+	return string(pair.Value), true, err
+}
+
+// DeleteEntry is used to delete an ID
+func (c *ConsulDB) DeleteEntry(key string) error {
+
+	kv := c.consulClient.KV()
+
+	_, err := kv.Delete(key, nil)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// ReadAll is used to get all ExternalIDs in a namespace
+func (c *ConsulDB) ReadAll(prefix string) ([]string, error) {
+	kv := c.consulClient.KV()
+
+	pairs, _, err := kv.List(prefix, nil)
+
+	if len(pairs) == 0 {
+		return []string{""}, err
+	}
+
+	var res []string
+
+	for _, keypair := range pairs {
+		res = append(res, keypair.Key)
+	}
+
+	return res, err
+}
diff --git a/src/k8splugin/db/db_test.go b/src/k8splugin/db/db_test.go
new file mode 100644
index 00000000..7ad252f5
--- /dev/null
+++ b/src/k8splugin/db/db_test.go
@@ -0,0 +1,40 @@
+/*
+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"
+	"testing"
+)
+
+func TestCreateDBClient(t *testing.T) {
+	oldDBconn := DBconn
+
+	defer func() {
+		DBconn = oldDBconn
+	}()
+
+	t.Run("Successfully create DB client", func(t *testing.T) {
+		expectedDB := ConsulDB{}
+
+		err := CreateDBClient("consul")
+		if err != nil {
+			t.Fatalf("TestCreateDBClient returned an error (%s)", err)
+		}
+
+		if !reflect.DeepEqual(DBconn, &expectedDB) {
+			t.Fatalf("TestCreateDBClient set DBconn as:\n result=%v\n expected=%v", DBconn, expectedDB)
+		}
+	})
+}