Add feature to hold configs in filesystem

This patch adds feature to hold config files
on filesystem and adds all unit tests to have
enough coverage for milestones.

Change-Id: Icd6f3dc93e0f419500f82f0a6ccd62e500dfc918
Issue-ID: MUSIC-42
Signed-off-by: Shashank Kumar Shankar <shashank.kumar.shankar@intel.com>

1 files changed, 133 insertions, 0 deletions

diff --git a/src/dkv/api/backendConsulConnection.go b/src/dkv/api/backendConsulConnection.go
new file mode 100644
index 0000000..9c2f8d6
--- /dev/null
+++ b/src/dkv/api/backendConsulConnection.go
@@ -0,0 +1,133 @@
+/*
+ * 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 api
+
+import (
+	"errors"
+	consulapi "github.com/hashicorp/consul/api"
+	"os"
+)
+
+// Interface to have all signature methods.
+type ConsulRequester interface {
+	InitializeConsulClient() error
+	CheckConsulHealth() error
+	RequestPUT(string, string) error
+	RequestGET(string) (string, error)
+	RequestGETS() ([]string, error)
+	RequestDELETE(string) error
+}
+
+type ConsulStruct struct {
+	consulClient *consulapi.Client
+}
+
+/*
+This var is an interface used to initialize ConsulStruct when the who API is brought up. This is done this way so
+that a fake Consul can be created which satisfies the interface and we can use that fake Consul in unit testing.
+*/
+var Consul ConsulRequester
+
+/*
+The following functions seems like they are not used. But since they are following the ConsulRequest interface,
+they can be visible to any Struct which is initiated using the ConsulRequest. This is done for this project in
+the initialise.go file where we are creating a ConsulStruct and assigning it to Consul var which is declared
+above.
+*/
+func (c *ConsulStruct) InitializeConsulClient() error {
+	if os.Getenv("CONSUL_IP") == "" {
+		return errors.New("CONSUL_IP environment variable not set.")
+	}
+	config := consulapi.DefaultConfig()
+	config.Address = os.Getenv("CONSUL_IP") + ":8500"
+
+	client, err := consulapi.NewClient(config)
+	if err != nil {
+		return err
+	}
+	c.consulClient = client
+
+	return nil
+}
+
+func (c *ConsulStruct) CheckConsulHealth() error {
+	kv := c.consulClient.KV()
+	_, _, err := kv.Get("test", nil)
+	if err != nil {
+		return errors.New("[ERROR] Cannot talk to Consul. Check if it is running/reachable.")
+	}
+	return nil
+}
+
+func (c *ConsulStruct) RequestPUT(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
+}
+
+func (c *ConsulStruct) RequestGET(key string) (string, error) {
+
+	kv := c.consulClient.KV()
+
+	pair, _, err := kv.Get(key, nil)
+
+	if pair == nil {
+		return string("No value found for key."), err
+	}
+	return string(pair.Value), err
+
+}
+
+func (c *ConsulStruct) RequestGETS() ([]string, error) {
+
+	kv := c.consulClient.KV()
+
+	pairs, _, err := kv.List("", nil)
+
+	if len(pairs) == 0 {
+		return []string{"No keys found."}, err
+	}
+
+	var res []string
+
+	for _, keypair := range pairs {
+		res = append(res, keypair.Key)
+	}
+
+	return res, err
+}
+
+func (c *ConsulStruct) RequestDELETE(key string) error {
+	kv := c.consulClient.KV()
+
+	_, err := kv.Delete(key, nil)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}