Merge pull request #4 from Piszmog/develop

Add additional function for creating a local client to the config server

README.md

@@ -21,8 +21,9 @@ of the Config Server do not provide the endpoint necessary to retrieve files for
 ## Example Usage
 Below is an example usage of the library to retrieve a file from the Config Server and to retrieve the application's configurations
 
-* For local config client, ensure `CONFIG_SERVER_URLS` is set
-  * `CONFIG_SERVER_URLS` is a comma separated list of all the base URLs
+* For local config client, there are two ways the create a client
+  1. Call `client.CreateLocalClientFromEnv()`. Set the environment variable `CONFIG_SERVER_URLS`. It is a comma separated list of all the base URLs
+  2. Call `CreateLocalClient(baseUrls []string)`. Provide the array of base URLs of Config Servers.
 * For running in Cloud Foundry, ensure a Config Server is bounded to the application. `VCAP_SERVICES` will be provided as an environment variables with the credentials to access the Config Server
 * For connecting to a Config Server via OAuth2 and not deployed to Cloud Foundry, an OAuth2 Client can be created with `CreateOAuth2Client(credentials []cfservices.Credentials)`
 
@@ -45,7 +46,9 @@ type Example struct {
 
 func main() {
 	// To create a Client for a locally running Spring Config Server
-	configClient, err := client.CreateLocalClient()
+	configClient, err := client.CreateLocalClientFromEnv()
+	// Or
+	configClient, err := client.CreateLocalClient([]string{"http://localhost:8888"})
 	// or to create a Client for a Spring Config Server in Cloud Foundry
 	configClient, err := client.CreateCloudClient()
 	// or to create a Client for a Spring Config Server with OAuth2
@@ -55,9 +58,7 @@ func main() {
 		ClientId:       "client id",
 		AccessTokenUri: "access token uri",
 	}
-	creds := make([]cfservices.Credentials, 1)
-	creds[0] = credentials
-	configClient, err := client.CreateOAuth2Client(creds)
+	configClient, err := client.CreateOAuth2Client([]cfservices.Credentials{credentials})
 
 	if err != nil {
 		panic(err)
@@ -79,17 +80,6 @@ func main() {
 }
 ```
 
-## Config Client Creation
-There are two type of clients that can be created. A local client for a locally running Config Server without security (OAuth2) 
-and a cloud client for a Config Server running in a cloud environment.
-
-### Local
-To create a local client, call `client.CreateLocalClient()`. The client is configured with timeouts set and to use a pool of connections.
-
-### Cloud
-To create a cloud client, call `client.CreateCloudClient()`. The client is an OAuth2 client (client credentials). 
-The OAuth2 configurations are determined from the `VCAP_SERVICES` environment variable.
-
 #### VCAP_SERVICES
 When an application is deployed to Cloud Foundry, services can be bounded to the application. When a service is bounded to an application, 
 the application will have the necessary connection information provided in the environment variable `VCAP_SERVICES`.

client/local.go

@@ -13,17 +13,29 @@ const (
 	EnvironmentLocalConfigServerUrls = "CONFIG_SERVER_URLS"
 )
 
-// CreateLocalClient creates a ConfigClient for a locally running Config Server.
+// CreateLocalClientFromEnv creates a ConfigClient for a locally running Config Server. Acquires the base URLs from the
+// environment variable 'CONFIG_SERVER_URLS'.
 //
 // The ConfigClient's underlying http.Client is configured with timeouts and connection pools.
-func CreateLocalClient() (*ConfigClient, error) {
+func CreateLocalClientFromEnv() (*ConfigClient, error) {
 	serviceCredentials, err := GetLocalCredentials()
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to create a local client")
 	}
-	configClients := make([]CloudClient, len(serviceCredentials.Credentials))
+	baseUrls := make([]string, len(serviceCredentials.Credentials))
 	for index, cred := range serviceCredentials.Credentials {
-		configUri := cred.Uri
+		baseUrls[index] = cred.Uri
+	}
+	return CreateLocalClient(baseUrls)
+}
+
+// CreateLocalClient creates a ConfigClient for a locally running Config Server.
+//
+// The ConfigClient's underlying http.Client is configured with timeouts and connection pools.
+func CreateLocalClient(baseUrls []string) (*ConfigClient, error) {
+	configClients := make([]CloudClient, len(baseUrls))
+	for index, baseUrl := range baseUrls {
+		configUri := baseUrl
 		client := httpclient.CreateDefaultHttpClient()
 		configClients[index] = Client{configUri: configUri, httpClient: client}
 	}

client/local_test.go

@@ -9,7 +9,7 @@ func TestCreateLocalClient(t *testing.T) {
 	const localURI = "http://localhost:8080"
 	os.Setenv(EnvironmentLocalConfigServerUrls, localURI)
 	defer os.Unsetenv(EnvironmentLocalConfigServerUrls)
-	configClient, err := CreateLocalClient()
+	configClient, err := CreateLocalClientFromEnv()
 	if err != nil {
 		t.Errorf("failed to create local client with error %v", err)
 	}
@@ -19,7 +19,7 @@ func TestCreateLocalClient(t *testing.T) {
 }
 
 func TestCreateLocalClientWhenENVNotSet(t *testing.T) {
-	configClient, err := CreateLocalClient()
+	configClient, err := CreateLocalClientFromEnv()
 	if err == nil {
 		t.Errorf("failed to create local client with error %v", err)
 	}