Merge pull request #14 from digitalocean/mdl-ovsdb-crash

ovsdb: don't crash on unhandled callback RPC

Author: mdlayher

ovsdb/client.go

@@ -213,7 +213,7 @@ func (c *Client) doCallback(id int, res rpcResponse) {
 	ch, ok := c.callbacks[id]
 	if !ok {
 		// Nobody is listening to this callback.
-		panicf("OVSDB callback with ID %d has no listeners", id)
+		return
 	}
 
 	// Return result, clean up channel, and remove this callback.

ovsdb/client_test.go

@@ -73,6 +73,26 @@ func TestClientOVSDBError(t *testing.T) {
 	}
 }
 
+func TestClientBadCallback(t *testing.T) {
+	c, notifC, done := testClient(t, func(_ jsonrpc.Request) jsonrpc.Response {
+		return jsonrpc.Response{
+			ID:     intPtr(1),
+			Result: mustMarshalJSON(t, []string{"foo"}),
+		}
+	})
+	defer done()
+
+	// Client doesn't have a callback for this ID.
+	notifC <- &jsonrpc.Response{
+		Method: "crash",
+		ID:     intPtr(10),
+	}
+
+	if _, err := c.ListDatabases(); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
 func testClient(t *testing.T, fn jsonrpc.TestFunc) (*ovsdb.Client, chan<- *jsonrpc.Response, func()) {
 	t.Helper()