decode API Server response body on error

Signed-off-by: Tim Ramlot <42113979+inteon@users.noreply.github.com>

Author: inteon

pkg/datagatherer/oidc/oidc.go

@@ -89,11 +89,12 @@ func (g *DataGathererOIDC) Fetch() (any, int, error) {
 
 func (g *DataGathererOIDC) fetchOIDCConfig(ctx context.Context) (map[string]any, error) {
 	// Fetch the OIDC discovery document from the well-known endpoint.
-	bytes, err := g.cl.Get().AbsPath("/.well-known/openid-configuration").Do(ctx).Raw()
-	if err != nil {
+	result := g.cl.Get().AbsPath("/.well-known/openid-configuration").Do(ctx)
+	if err := result.Error(); err != nil {
 		return nil, fmt.Errorf("failed to get OIDC discovery document: %s", k8sErrorMessage(err))
 	}
 
+	bytes, _ := result.Raw()
 	var oidcResponse map[string]any
 	if err := json.Unmarshal(bytes, &oidcResponse); err != nil {
 		return nil, fmt.Errorf("failed to unmarshal OIDC discovery document: %v", err)
@@ -109,11 +110,12 @@ func (g *DataGathererOIDC) fetchJWKS(ctx context.Context) (map[string]any, error
 	//  - on fully private AWS EKS clusters, the URL is still public and might not
 	//    be reachable from within the cluster (https://github.com/aws/containers-roadmap/issues/2038)
 	// So we are using the default path instead, which we think should work in most cases.
-	bytes, err := g.cl.Get().AbsPath("/openid/v1/jwks").Do(ctx).Raw()
-	if err != nil {
+	result := g.cl.Get().AbsPath("/openid/v1/jwks").Do(ctx)
+	if err := result.Error(); err != nil {
 		return nil, fmt.Errorf("failed to get JWKS from jwks_uri: %s", k8sErrorMessage(err))
 	}
 
+	bytes, _ := result.Raw()
 	var jwksResponse map[string]any
 	if err := json.Unmarshal(bytes, &jwksResponse); err != nil {
 		return nil, fmt.Errorf("failed to unmarshal JWKS response: %v", err)