Move configuration into config files

Move k8splugin configuration into config files
instead of using environment variables.

Issue-ID: MULTICLOUD-579
Change-Id: I7b76d5a14d24f002a8db484097a31fb5e908b6f8
Signed-off-by: Kiran Kamineni <kiran.k.kamineni@intel.com>

8 files changed, 192 insertions, 43 deletions

diff --git a/src/k8splugin/internal/app/client_test.go b/src/k8splugin/internal/app/client_test.go
index d023fcff..4cc533e2 100644
--- a/src/k8splugin/internal/app/client_test.go
+++ b/src/k8splugin/internal/app/client_test.go
@@ -48,7 +48,7 @@ func TestInit(t *testing.T) {
 	t.Run("Successfully create Kube Client", func(t *testing.T) {
 
 		kubeClient := KubernetesClient{}
-		err := kubeClient.init("../../mock_files/mock_configs/mock_config")
+		err := kubeClient.init("../../mock_files/mock_configs/mock_kube_config")
 		if err != nil {
 			t.Fatalf("TestGetKubeClient returned an error (%s)", err)
 		}
diff --git a/src/k8splugin/internal/app/instance.go b/src/k8splugin/internal/app/instance.go
index 8e9a2b7a..8d289d85 100644
--- a/src/k8splugin/internal/app/instance.go
+++ b/src/k8splugin/internal/app/instance.go
@@ -20,8 +20,8 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"math/rand"
-	"os"
 
+	"k8splugin/internal/config"
 	"k8splugin/internal/db"
 	"k8splugin/internal/helm"
 	"k8splugin/internal/rb"
@@ -120,7 +120,7 @@ func (v *InstanceClient) Create(i InstanceRequest) (InstanceResponse, error) {
 	}
 
 	k8sClient := KubernetesClient{}
-	err = k8sClient.init(os.Getenv("KUBE_CONFIG_DIR") + "/" + i.CloudRegion)
+	err = k8sClient.init(config.GetConfiguration().KubeConfigDir + "/" + i.CloudRegion)
 	if err != nil {
 		return InstanceResponse{}, pkgerrors.Wrap(err, "Getting CloudRegion Information")
 	}
@@ -185,7 +185,7 @@ func (v *InstanceClient) Delete(id string) error {
 	}
 
 	k8sClient := KubernetesClient{}
-	err = k8sClient.init(os.Getenv("KUBE_CONFIG_DIR") + "/" + inst.CloudRegion)
+	err = k8sClient.init(config.GetConfiguration().KubeConfigDir + "/" + inst.CloudRegion)
 	if err != nil {
 		return pkgerrors.Wrap(err, "Getting CloudRegion Information")
 	}
diff --git a/src/k8splugin/internal/app/instance_test.go b/src/k8splugin/internal/app/instance_test.go
index 3828ed38..ab39dfb7 100644
--- a/src/k8splugin/internal/app/instance_test.go
+++ b/src/k8splugin/internal/app/instance_test.go
@@ -15,11 +15,11 @@ package app
 
 import (
 	"log"
-	"os"
 	"reflect"
 	"testing"
 
 	utils "k8splugin/internal"
+	"k8splugin/internal/config"
 	"k8splugin/internal/db"
 	"k8splugin/internal/helm"
 	"k8splugin/internal/rb"
@@ -153,14 +153,10 @@ func TestInstanceCreate(t *testing.T) {
 			RBName:      "test-rbdef",
 			RBVersion:   "v1",
 			ProfileName: "profile1",
-			CloudRegion: "mock_config",
-		}
-
-		err := os.Setenv("KUBE_CONFIG_DIR", "../../mock_files/mock_configs")
-		if err != nil {
-			t.Fatalf("TestInstanceCreate returned an error (%s)", err)
+			CloudRegion: "mock_kube_config",
 		}
 
+		config.SetConfigValue("KubeConfigDir", "../../mock_files/mock_configs")
 		ir, err := ic.Create(input)
 		if err != nil {
 			t.Fatalf("TestInstanceCreate returned an error (%s)", err)
@@ -326,7 +322,7 @@ func TestInstanceDelete(t *testing.T) {
 							"namespace":"testnamespace",
 							"rb-name":"test-rbdef",
 							"rb-version":"v1",
-							"cloud-region":"mock_config",
+							"cloud-region":"mock_kube_config",
 							"resources": [
 								{
 									"GVK": {
@@ -369,7 +365,7 @@ func TestInstanceDelete(t *testing.T) {
 							"namespace":"testnamespace",
 							"rb-name":"test-rbdef",
 							"rb-version":"v1",
-							"cloud-region":"mock_config",
+							"cloud-region":"mock_kube_config",
 							"resources": [
 								{
 									"GVK": {
diff --git a/src/k8splugin/internal/config/config.go b/src/k8splugin/internal/config/config.go
new file mode 100644
index 00000000..c3ca9054
--- /dev/null
+++ b/src/k8splugin/internal/config/config.go
@@ -0,0 +1,128 @@
+/*
+ * Copyright 2019 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 config
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"reflect"
+)
+
+// Configuration loads up all the values that are used to configure
+// backend implementations
+type Configuration struct {
+	CAFile            string `json:"ca-file"`
+	ServerCert        string `json:"server-cert"`
+	ServerKey         string `json:"server-key"`
+	Password          string `json:"password"`
+	DatabaseAddress   string `json:"database-address"`
+	DatabaseType      string `json:"database-type"`
+	PluginDir         string `json:"plugin-dir"`
+	EtcdIP            string `json:"etcd-ip"`
+	EtcdCert          string `json:"etcd-cert"`
+	EtcdKey           string `json:"etcd-key"`
+	EtcdCAFile        string `json:"etcd-ca-file"`
+	KubeConfigDir     string `json:"kube-config-dir"`
+	OVNCentralAddress string `json:"ovn-central-address"`
+}
+
+// Config is the structure that stores the configuration
+var gConfig *Configuration
+
+// readConfigFile reads the specified smsConfig file to setup some env variables
+func readConfigFile(file string) (*Configuration, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return defaultConfiguration(), err
+	}
+	defer f.Close()
+
+	// Setup some defaults here
+	// If the json file has values in it, the defaults will be overwritten
+	conf := defaultConfiguration()
+
+	// Read the configuration from json file
+	decoder := json.NewDecoder(f)
+	err = decoder.Decode(conf)
+	if err != nil {
+		return conf, err
+	}
+
+	return conf, nil
+}
+
+func defaultConfiguration() *Configuration {
+	cwd, err := os.Getwd()
+	if err != nil {
+		log.Println("Error getting cwd. Using .")
+		cwd = "."
+	}
+
+	return &Configuration{
+		CAFile:            "ca.cert",
+		ServerCert:        "server.cert",
+		ServerKey:         "server.key",
+		Password:          "",
+		DatabaseAddress:   "127.0.0.1",
+		DatabaseType:      "mongo",
+		PluginDir:         cwd,
+		EtcdIP:            "127.0.0.1",
+		EtcdCert:          "etcd.cert",
+		EtcdKey:           "etcd.key",
+		EtcdCAFile:        "etcd-ca.cert",
+		KubeConfigDir:     cwd,
+		OVNCentralAddress: "127.0.0.1",
+	}
+}
+
+// GetConfiguration returns the configuration for the app.
+// It will try to load it if it is not already loaded.
+func GetConfiguration() *Configuration {
+	if gConfig == nil {
+		conf, err := readConfigFile("k8sconfig.json")
+		if err != nil {
+			log.Println("Error loading config file. Using defaults.")
+		}
+		gConfig = conf
+	}
+
+	return gConfig
+}
+
+// SetConfigValue sets a value in the configuration
+// This is mostly used to customize the application and
+// should be used carefully.
+func SetConfigValue(key string, value string) *Configuration {
+	c := GetConfiguration()
+	if value == "" || key == "" {
+		return c
+	}
+
+	v := reflect.ValueOf(c).Elem()
+	if v.Kind() == reflect.Struct {
+		f := v.FieldByName(key)
+		if f.IsValid() {
+			if f.CanSet() {
+				if f.Kind() == reflect.String {
+					f.SetString(value)
+				}
+			}
+		}
+	}
+	return c
+}
diff --git a/src/k8splugin/internal/config/config_test.go b/src/k8splugin/internal/config/config_test.go
new file mode 100644
index 00000000..ddebfb27
--- /dev/null
+++ b/src/k8splugin/internal/config/config_test.go
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2019 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 config
+
+import (
+	"testing"
+)
+
+func TestReadConfigurationFile(t *testing.T) {
+	t.Run("Non Existent Configuration File", func(t *testing.T) {
+		_, err := readConfigFile("filedoesnotexist.json")
+		if err == nil {
+			t.Fatal("ReadConfiguationFile: Expected Error, got nil")
+		}
+	})
+
+	t.Run("Read Configuration File", func(t *testing.T) {
+		conf, err := readConfigFile("../../mock_files/mock_configs/mock_config.json")
+		if err != nil {
+			t.Fatal("ReadConfigurationFile: Error reading file")
+		}
+		if conf.DatabaseType != "mock_db_test" {
+			t.Fatal("ReadConfigurationFile: Incorrect entry read from file")
+		}
+	})
+}
diff --git a/src/k8splugin/internal/db/consul.go b/src/k8splugin/internal/db/consul.go
index 0977cfba..40028c64 100644
--- a/src/k8splugin/internal/db/consul.go
+++ b/src/k8splugin/internal/db/consul.go
@@ -14,7 +14,7 @@ limitations under the License.
 package db
 
 import (
-	"os"
+	k8sconfig "k8splugin/internal/config"
 
 	"github.com/hashicorp/consul/api"
 	pkgerrors "github.com/pkg/errors"
@@ -38,7 +38,7 @@ type ConsulStore struct {
 func NewConsulStore(store ConsulKVStore) (Store, error) {
 	if store == nil {
 		config := api.DefaultConfig()
-		config.Address = os.Getenv("DATABASE_IP") + ":8500"
+		config.Address = k8sconfig.GetConfiguration().DatabaseAddress + ":8500"
 
 		consulClient, err := api.NewClient(config)
 		if err != nil {
diff --git a/src/k8splugin/internal/db/mongo.go b/src/k8splugin/internal/db/mongo.go
index a9e9d98a..d4525222 100644
--- a/src/k8splugin/internal/db/mongo.go
+++ b/src/k8splugin/internal/db/mongo.go
@@ -19,7 +19,8 @@ package db
 import (
 	"golang.org/x/net/context"
 	"log"
-	"os"
+
+	"k8splugin/internal/config"
 
 	pkgerrors "github.com/pkg/errors"
 	"go.mongodb.org/mongo-driver/bson"
@@ -76,7 +77,7 @@ var cursorClose = func(ctx context.Context, cursor *mongo.Cursor) error {
 // 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://" + os.Getenv("DATABASE_IP") + ":27017"
+		ip := "mongodb://" + config.GetConfiguration().DatabaseAddress + ":27017"
 		clientOptions := options.Client()
 		clientOptions.ApplyURI(ip)
 		mongoClient, err := mongo.NewClient(clientOptions)
diff --git a/src/k8splugin/internal/utils.go b/src/k8splugin/internal/utils.go
index 3b08dd26..7785733d 100644
--- a/src/k8splugin/internal/utils.go
+++ b/src/k8splugin/internal/utils.go
@@ -15,13 +15,15 @@ package utils
 
 import (
 	"io/ioutil"
-	"k8splugin/internal/db"
 	"log"
 	"os"
 	"path/filepath"
 	"plugin"
 	"strings"
 
+	"k8splugin/internal/config"
+	"k8splugin/internal/db"
+
 	pkgerrors "github.com/pkg/errors"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/kubernetes/scheme"
@@ -65,23 +67,10 @@ var DecodeYAML = func(path string, into runtime.Object) (runtime.Object, error)
 	return obj, nil
 }
 
-// CheckEnvVariables checks for required Environment variables
-func CheckEnvVariables() error {
-	envList := []string{"CSAR_DIR", "KUBE_CONFIG_DIR", "PLUGINS_DIR",
-		"DATABASE_TYPE", "DATABASE_IP", "OVN_CENTRAL_ADDRESS"}
-	for _, env := range envList {
-		if _, ok := os.LookupEnv(env); !ok {
-			return pkgerrors.New("environment variable " + env + " not set")
-		}
-	}
-
-	return nil
-}
-
 // CheckDatabaseConnection checks if the database is up and running and
 // plugin can talk to it
 func CheckDatabaseConnection() error {
-	err := db.CreateDBClient(os.Getenv("DATABASE_TYPE"))
+	err := db.CreateDBClient(config.GetConfiguration().DatabaseType)
 	if err != nil {
 		return pkgerrors.Cause(err)
 	}
@@ -92,10 +81,10 @@ func CheckDatabaseConnection() error {
 	}
 	// TODO Convert these to configuration files instead of environment variables.
 	c := db.EtcdConfig{
-		Endpoint: os.Getenv("ETCD_ENDPOINT_IP"),
-		CertFile: os.Getenv("ETCD_CERT_FILE"),
-		KeyFile:  os.Getenv("ETCD_KEY_FILE"),
-		CAFile:   os.Getenv("ETCD_TRUSTED_CA_FILE"),
+		Endpoint: config.GetConfiguration().EtcdIP,
+		CertFile: config.GetConfiguration().EtcdCert,
+		KeyFile:  config.GetConfiguration().EtcdKey,
+		CAFile:   config.GetConfiguration().EtcdCAFile,
 	}
 	err = db.NewEtcdClient(nil, c)
 	if err != nil {
@@ -106,7 +95,7 @@ func CheckDatabaseConnection() error {
 
 // LoadPlugins loads all the compiled .so plugins
 func LoadPlugins() error {
-	pluginsDir := os.Getenv("PLUGINS_DIR")
+	pluginsDir := config.GetConfiguration().PluginDir
 	err := filepath.Walk(pluginsDir,
 		func(path string, info os.FileInfo, err error) error {
 			if strings.Contains(path, ".so") {
@@ -127,12 +116,7 @@ func LoadPlugins() error {
 
 // CheckInitialSettings is used to check initial settings required to start api
 func CheckInitialSettings() error {
-	err := CheckEnvVariables()
-	if err != nil {
-		return pkgerrors.Cause(err)
-	}
-
-	err = CheckDatabaseConnection()
+	err := CheckDatabaseConnection()
 	if err != nil {
 		return pkgerrors.Cause(err)
 	}