adds support for default auth, to support the usage og managed identi…

…ties

receiver/azureblobreceiver/README.md

@@ -24,7 +24,7 @@ The following settings are required:
 
 The following settings can be optionally configured:
 
-- `auth` (default = connection_string): Specifies the used authentication method. Supported values are `connection_string`, `service_principal`.
+- `auth` (default = connection_string): Specifies the used authentication method. Supported values are `connection_string`, `service_principal`, `default`.
 - `cloud` (default = "AzureCloud"): Defines which Azure Cloud to use when using the `service_principal` authentication method. Value is either `AzureCloud` or `AzureUSGovernment`.
 - `logs:`
   `  container_name:` (default = "logs"): Name of the blob container with the logs

receiver/azureblobreceiver/config.go

@@ -69,16 +69,17 @@ type AuthType string
 const (
 	ServicePrincipalAuth AuthType = "service_principal"
 	ConnectionStringAuth AuthType = "connection_string"
+	DefaultAuth          AuthType = "default"
 )
 
 func (e *AuthType) UnmarshalText(text []byte) error {
 	str := AuthType(text)
 	switch str {
-	case ServicePrincipalAuth, ConnectionStringAuth:
+	case ServicePrincipalAuth, ConnectionStringAuth, DefaultAuth:
 		*e = str
 		return nil
 	default:
-		return fmt.Errorf("authentication %v is not supported. supported authentications include [%v,%v]", str, ServicePrincipalAuth, ConnectionStringAuth)
+		return fmt.Errorf("authentication %v is not supported. supported authentications include [%v,%v,%v]", str, ServicePrincipalAuth, ConnectionStringAuth, DefaultAuth)
 	}
 }
 

receiver/azureblobreceiver/factory.go

@@ -141,6 +141,15 @@ func (f *blobReceiverFactory) getBlobEventHandler(cfg *Config, logger *zap.Logge
 		if err != nil {
 			return nil, err
 		}
+	case DefaultAuth:
+		cred, err := azidentity.NewDefaultAzureCredential(nil)
+		if err != nil {
+			return nil, err
+		}
+		bc, err = newBlobClientFromCredential(cfg.StorageAccountURL, cred, logger)
+		if err != nil {
+			return nil, err
+		}
 	default:
 		return nil, fmt.Errorf("unknown authentication %v", cfg.Authentication)
 	}