Fix GCS credentials when no endpoint specified (#138)

* GCS: Use default HTTP client when endpoint is not set. Fixes #137.

* Updated changelog with #138.

Co-authored-by: Kemal Akkoyun <kakkoyun@users.noreply.github.com>

CHANGELOG.md

@@ -7,9 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
-- Fixed Anonymous Credentials Error on public buckets
+- [#133](https://github.com/meltwater/drone-cache/pull/133) bacnkend/s3: Fixed Anonymous Credentials Error on public buckets. 
   - Fixes [#132](https://github.com/meltwater/drone-cache/issues/132)
-- [#135](https://github.com/meltwater/drone-cache/issues/135) Fixed parsing of GCS JSON key.
+- [#138](https://github.com/meltwater/drone-cache/pull/138) backend/gcs: Fix GCS to pass credentials correctly when `GCS_ENDPOINT` is not set.
+- [#135](https://github.com/meltwater/drone-cache/issues/135) backend/gcs: Fixed parsing of GCS JSON key.
 
 ### Added
 

storage/backend/gcs/gcs.go

@@ -35,16 +35,16 @@ func New(l log.Logger, c Config) (*Backend, error) {
 
 	if c.Endpoint != "" {
 		opts = append(opts, option.WithEndpoint(c.Endpoint))
-	}
 
-	if !strings.HasPrefix(c.Endpoint, "https://") { // This is not settable from outside world, only used for mock tests.
-		opts = append(opts, option.WithHTTPClient(&http.Client{Transport: &http.Transport{
-			// ignore unverified/expired SSL certificates for tests.
-			TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, //nolint:gosec
-		}}))
+		if !strings.HasPrefix(c.Endpoint, "https://") { // This is not settable from outside world, only used for mock tests.
+			opts = append(opts, option.WithHTTPClient(&http.Client{Transport: &http.Transport{
+				// ignore unverified/expired SSL certificates for tests.
+				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, //nolint:gosec
+			}}))
+		}
 	}
 
-	setAuthenticationMethod(l, c, opts)
+	opts = setAuthenticationMethod(l, c, opts)
 
 	ctx, cancel := context.WithTimeout(context.Background(), c.Timeout)
 	defer cancel()