Add simple CLI support. (#41)

Author: Mike Davis

README.md

@@ -1 +1,55 @@
 # Optimizely Go SDK
+
+## Command line interface
+A CLI has been provided to illustrate the functionality of the SDK. Simply run `go-sdk` for help.
+```$sh
+go-sdk provides cli access to your Optimizely fullstack project
+
+Usage:
+  go-sdk [command]
+
+Available Commands:
+  help               Help about any command
+  is_feature_enabled Is feature enabled?
+
+Flags:
+  -h, --help            help for go-sdk
+  -s, --sdkKey string   Optimizely project SDK key
+
+Use "go-sdk [command] --help" for more information about a command.
+```
+
+Each supported SDK API method is it's own [cobra](https://github.com/spf13/cobra) command and requires the
+input of an `--sdkKey`.
+
+### Installation
+Install the CLI from github:
+
+```$sh
+go install github.com/optimizely/go-sdk
+```
+
+Install the CLI from source:
+```$sh
+go get github.com/optimizely/go-sdk
+cd $GOPATH/src/github.com/optimizely/go-sdk
+go install
+```
+
+### Commands
+
+#### is_feature_enabled
+```
+Determines if a feature is enabled
+
+Usage:
+  go-sdk is_feature_enabled [flags]
+
+Flags:
+  -f, --featureKey string   feature key to enable
+  -h, --help                help for is_feature_enabled
+  -u, --userId string       user id
+
+Global Flags:
+  -s, --sdkKey string   Optimizely project SDK key
+  ```

cmd/is_feature_enabled.go

@@ -0,0 +1,63 @@
+/****************************************************************************
+ * Copyright 2019, Optimizely, Inc. and contributors                        *
+ *                                                                          *
+ * 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 cmd
+
+import (
+	"fmt"
+	"github.com/optimizely/go-sdk/optimizely/client"
+	"github.com/optimizely/go-sdk/optimizely/entities"
+	"github.com/spf13/cobra"
+)
+
+var (
+	userId string
+	featurekKey string
+)
+
+var isFeatureEnabledCmd = &cobra.Command{
+	Use:   "is_feature_enabled",
+	Short: "Is feature enabled?",
+	Long:  `Determines if a feature is enabled`,
+	Run: func(cmd *cobra.Command, args []string) {
+		optimizelyFactory := &client.OptimizelyFactory{
+			SDKKey: sdkKey,
+		}
+
+		client, err := optimizelyFactory.Client()
+
+		if err != nil {
+			fmt.Printf("Error instantiating client: %s\n", err)
+			return
+		}
+
+		user := entities.UserContext{
+			ID:         userId,
+			Attributes: entities.UserAttributes{},
+		}
+
+		enabled, _ := client.IsFeatureEnabled(featurekKey, user)
+		fmt.Printf("Is feature \"%s\" enabled for \"%s\"? %t\n", featurekKey, userId, enabled)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(isFeatureEnabledCmd)
+	isFeatureEnabledCmd.Flags().StringVarP(&userId, "userId", "u", "", "user id")
+	isFeatureEnabledCmd.MarkFlagRequired("userId")
+	isFeatureEnabledCmd.Flags().StringVarP(&featurekKey, "featureKey", "f", "", "feature key to enable")
+	isFeatureEnabledCmd.MarkFlagRequired("featureKey")
+}

cmd/root.go

@@ -0,0 +1,43 @@
+/****************************************************************************
+ * Copyright 2019, Optimizely, Inc. and contributors                        *
+ *                                                                          *
+ * 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 cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var sdkKey string
+
+var rootCmd = &cobra.Command{
+	Use:   "go-sdk",
+	Short: "go-sdk provides cli access to your Optimizely fullstack project",
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func init() {
+	rootCmd.PersistentFlags().StringVarP(&sdkKey, "sdkKey", "s", "", "Optimizely project SDK key")
+	rootCmd.MarkPersistentFlagRequired("sdkKey")
+}

examples/main.go

@@ -14,7 +14,12 @@ func main() {
 	optimizelyFactory := &client.OptimizelyFactory{
 		SDKKey: "ABC",
 	}
-	client := optimizelyFactory.Client()
+	client, err := optimizelyFactory.Client()
+
+	if err != nil {
+		fmt.Printf("Error instantiating client: %s", err)
+		return
+	}
 
 	user := entities.UserContext{
 		ID:         "mike ng",

main.go

@@ -0,0 +1,23 @@
+/****************************************************************************
+ * Copyright 2019, Optimizely, Inc. and contributors                        *
+ *                                                                          *
+ * 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 main
+
+import "github.com/optimizely/go-sdk/cmd"
+
+func main() {
+	cmd.Execute()
+}

optimizely/client/factory.go

@@ -17,9 +17,10 @@
 package client
 
 import (
+
 	"github.com/optimizely/go-sdk/optimizely"
+	"fmt"
 	"github.com/optimizely/go-sdk/optimizely/config"
-	"github.com/optimizely/go-sdk/optimizely/config/datafileProjectConfig"
 	"github.com/optimizely/go-sdk/optimizely/decision"
 )
 
@@ -30,16 +31,27 @@ type OptimizelyFactory struct {
 }
 
 // Client returns a client initialized with the defaults
-func (f OptimizelyFactory) Client() OptimizelyClient {
-	var projectConfig optimizely.ProjectConfig
+func (f OptimizelyFactory) Client() (*OptimizelyClient, error) {
 	var configManager optimizely.ProjectConfigManager
-	if f.Datafile != nil {
-		projectConfig = datafileProjectConfig.NewDatafileProjectConfig(f.Datafile)
 
-		if f.SDKKey == "" {
-			staticConfigManager := config.NewStaticProjectConfigManager(projectConfig)
-			configManager = staticConfigManager
+	if f.SDKKey != "" {
+		url := fmt.Sprintf("https://cdn.optimizely.com/datafiles/%s.json", f.SDKKey)
+		staticConfigManager, err := config.NewStaticProjectConfigManagerFromUrl(url)
+
+		if err != nil {
+			return nil, err
 		}
+
+		configManager = staticConfigManager
+
+	} else if f.Datafile != nil {
+		staticConfigManager, err := config.NewStaticProjectConfigManagerFromPayload(f.Datafile)
+
+		if err != nil {
+			return nil, err
+		}
+
+		configManager = staticConfigManager
 	}
 
 	decisionService := decision.NewCompositeService()
@@ -48,5 +60,5 @@ func (f OptimizelyFactory) Client() OptimizelyClient {
 		configManager:   configManager,
 		isValid:         true,
 	}
-	return client
+	return &client, nil
 }

optimizely/config/datafileProjectConfig/config.go

@@ -68,10 +68,11 @@ func (c DatafileProjectConfig) GetBotFiltering() bool {
 }
 
 // NewDatafileProjectConfig initializes a new datafile from a json byte array using the default JSON datafile parser
-func NewDatafileProjectConfig(jsonDatafile []byte) *DatafileProjectConfig {
+func NewDatafileProjectConfig(jsonDatafile []byte) (*DatafileProjectConfig, error) {
 	datafile, err := Parse(jsonDatafile)
 	if err != nil {
 		logger.Error("Error parsing datafile.", err)
+		return nil, err
 	}
 
 	experiments, experimentKeyMap := mappers.MapExperiments(datafile.Experiments)
@@ -82,7 +83,7 @@ func NewDatafileProjectConfig(jsonDatafile []byte) *DatafileProjectConfig {
 	}
 
 	logger.Info("Datafile is valid.")
-	return config
+	return config, nil
 }
 
 // GetEventByKey returns the event with the given key

optimizely/config/static_manager.go

@@ -17,9 +17,14 @@
 package config
 
 import (
+	"bytes"
+	"errors"
+	"io"
+	"net/http"
 	"sync"
 
 	"github.com/optimizely/go-sdk/optimizely"
+	"github.com/optimizely/go-sdk/optimizely/config/datafileProjectConfig"
 )
 
 // StaticProjectConfigManager maintains a static copy of the project config
@@ -28,6 +33,43 @@ type StaticProjectConfigManager struct {
 	configLock    sync.Mutex
 }
 
+func NewStaticProjectConfigManagerFromUrl(URL string) (*StaticProjectConfigManager, error) {
+	downloadFile := func(URL string) ([]byte, error) {
+		response, err := http.Get(URL)
+		if err != nil {
+			return nil, err
+		}
+		defer response.Body.Close()
+		if response.StatusCode != http.StatusOK {
+			return nil, errors.New(response.Status)
+		}
+		var data bytes.Buffer
+		_, err = io.Copy(&data, response.Body)
+		if err != nil {
+			return nil, err
+		}
+		return data.Bytes(), nil
+	}
+
+	body, err := downloadFile(URL)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return NewStaticProjectConfigManagerFromPayload(body)
+}
+
+func NewStaticProjectConfigManagerFromPayload(payload []byte) (*StaticProjectConfigManager, error) {
+	projectConfig, err := datafileProjectConfig.NewDatafileProjectConfig(payload)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return NewStaticProjectConfigManager(projectConfig), nil
+}
+
 // NewStaticProjectConfigManager creates a new instance of the manager with the given project config
 func NewStaticProjectConfigManager(config optimizely.ProjectConfig) *StaticProjectConfigManager {
 	return &StaticProjectConfigManager{