fix: throw error if no network/volume is found (fix: #38) (#39)

* fix: throw error if no network/volume is found (fix: #38)

* feat: added also which network/volume was not found

Author: mxschmitt

driver.go

@@ -257,6 +257,9 @@ func (d *Driver) Create() error {
 		if err != nil {
 			return errors.Wrap(err, "could not get network by ID or name")
 		}
+		if network == nil {
+			return errors.Errorf("network '%s' not found", networkIDorName)
+		}
 		networks = append(networks, network)
 	}
 	srvopts.Networks = networks
@@ -267,6 +270,9 @@ func (d *Driver) Create() error {
 		if err != nil {
 			return errors.Wrap(err, "could not get volume by ID or name")
 		}
+		if volume == nil {
+			return errors.Errorf("volume '%s' not found", volumeIDorName)
+		}
 		volumes = append(volumes, volume)
 	}
 	srvopts.Volumes = volumes