consul: use a function for ingesting responses

consul/internal_endpoint.go

@@ -2,6 +2,7 @@ package consul
 
 import (
 	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/serf/serf"
 )
 
 // Internal endpoint is used to query the miscellaneous info that
@@ -63,6 +64,22 @@ func (m *Internal) EventFire(args *structs.EventFireRequest,
 	return m.srv.UserEvent(args.Name, args.Payload)
 }
 
+func (m *Internal) ingestKeyringResponse(
+	resp *serf.KeyResponse,
+	reply *structs.KeyringResponses) {
+
+	reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+		Datacenter: m.srv.config.Datacenter,
+		Messages:   resp.Messages,
+		Keys:       resp.Keys,
+		NumResp:    resp.NumResp,
+		NumNodes:   resp.NumNodes,
+		NumErr:     resp.NumErr,
+	})
+}
+
+// ListKeys will query the WAN and LAN gossip keyrings of all nodes, adding
+// results into a collective response as we go.
 func (m *Internal) ListKeys(
 	args *structs.KeyringRequest,
 	reply *structs.KeyringResponses) error {
@@ -71,28 +88,14 @@ func (m *Internal) ListKeys(
 	if err != nil {
 		return err
 	}
-	reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+	m.ingestKeyringResponse(respLAN, reply)
-		Datacenter: m.srv.config.Datacenter,
-		Messages:   respLAN.Messages,
-		Keys:       respLAN.Keys,
-		NumResp:    respLAN.NumResp,
-		NumNodes:   respLAN.NumNodes,
-		NumErr:     respLAN.NumErr,
-	})
 
 	if !args.Forwarded {
 		respWAN, err := m.srv.KeyManagerWAN().ListKeys()
 		if err != nil {
 			return err
 		}
-		reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+		m.ingestKeyringResponse(respWAN, reply)
-			Datacenter: m.srv.config.Datacenter,
-			Messages:   respWAN.Messages,
-			Keys:       respWAN.Keys,
-			NumResp:    respWAN.NumResp,
-			NumNodes:   respWAN.NumNodes,
-			NumErr:     respWAN.NumErr,
-		})
 
 		// Mark key rotation as being already forwarded, then forward.
 		args.Forwarded = true
@@ -102,32 +105,25 @@ func (m *Internal) ListKeys(
 	return nil
 }
 
+// InstallKey broadcasts a new encryption key to all nodes. This involves
+// installing a new key on every node across all datacenters.
 func (m *Internal) InstallKey(
 	args *structs.KeyringRequest,
 	reply *structs.KeyringResponses) error {
 
-	respLAN, _ := m.srv.KeyManagerLAN().InstallKey(args.Key)
+	respLAN, err := m.srv.KeyManagerLAN().InstallKey(args.Key)
-	reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+	if err != nil {
-		Datacenter: m.srv.config.Datacenter,
+		return err
-		Messages:   respLAN.Messages,
+	}
-		Keys:       respLAN.Keys,
+	m.ingestKeyringResponse(respLAN, reply)
-		NumResp:    respLAN.NumResp,
-		NumNodes:   respLAN.NumNodes,
-		NumErr:     respLAN.NumErr,
-	})
 
 	if !args.Forwarded {
-		respWAN, _ := m.srv.KeyManagerWAN().InstallKey(args.Key)
+		respWAN, err := m.srv.KeyManagerWAN().InstallKey(args.Key)
-		reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+		if err != nil {
-			Datacenter: m.srv.config.Datacenter,
+			return err
-			Messages:   respWAN.Messages,
+		}
-			Keys:       respWAN.Keys,
+		m.ingestKeyringResponse(respWAN, reply)
-			NumResp:    respWAN.NumResp,
-			NumNodes:   respWAN.NumNodes,
-			NumErr:     respWAN.NumErr,
-		})
 
-		// Mark key rotation as being already forwarded, then forward.
 		args.Forwarded = true
 		return m.srv.forwardAll("Internal.InstallKey", args, reply)
 	}
@@ -135,32 +131,25 @@ func (m *Internal) InstallKey(
 	return nil
 }
 
+// UseKey instructs all nodes to change the key they are using to
+// encrypt gossip messages.
 func (m *Internal) UseKey(
 	args *structs.KeyringRequest,
 	reply *structs.KeyringResponses) error {
 
-	respLAN, _ := m.srv.KeyManagerLAN().UseKey(args.Key)
+	respLAN, err := m.srv.KeyManagerLAN().UseKey(args.Key)
-	reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+	if err != nil {
-		Datacenter: m.srv.config.Datacenter,
+		return err
-		Messages:   respLAN.Messages,
+	}
-		Keys:       respLAN.Keys,
+	m.ingestKeyringResponse(respLAN, reply)
-		NumResp:    respLAN.NumResp,
-		NumNodes:   respLAN.NumNodes,
-		NumErr:     respLAN.NumErr,
-	})
 
 	if !args.Forwarded {
-		respWAN, _ := m.srv.KeyManagerWAN().UseKey(args.Key)
+		respWAN, err := m.srv.KeyManagerWAN().UseKey(args.Key)
-		reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+		if err != nil {
-			Datacenter: m.srv.config.Datacenter,
+			return err
-			Messages:   respWAN.Messages,
+		}
-			Keys:       respWAN.Keys,
+		m.ingestKeyringResponse(respWAN, reply)
-			NumResp:    respWAN.NumResp,
-			NumNodes:   respWAN.NumNodes,
-			NumErr:     respWAN.NumErr,
-		})
 
-		// Mark key rotation as being already forwarded, then forward.
 		args.Forwarded = true
 		return m.srv.forwardAll("Internal.UseKey", args, reply)
 	}
@@ -168,32 +157,24 @@ func (m *Internal) UseKey(
 	return nil
 }
 
+// RemoveKey instructs all nodes to drop the specified key from the keyring.
 func (m *Internal) RemoveKey(
 	args *structs.KeyringRequest,
 	reply *structs.KeyringResponses) error {
 
-	respLAN, _ := m.srv.KeyManagerLAN().RemoveKey(args.Key)
+	respLAN, err := m.srv.KeyManagerLAN().RemoveKey(args.Key)
-	reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+	if err != nil {
-		Datacenter: m.srv.config.Datacenter,
+		return err
-		Messages:   respLAN.Messages,
+	}
-		Keys:       respLAN.Keys,
+	m.ingestKeyringResponse(respLAN, reply)
-		NumResp:    respLAN.NumResp,
-		NumNodes:   respLAN.NumNodes,
-		NumErr:     respLAN.NumErr,
-	})
 
 	if !args.Forwarded {
-		respWAN, _ := m.srv.KeyManagerWAN().RemoveKey(args.Key)
+		respWAN, err := m.srv.KeyManagerWAN().RemoveKey(args.Key)
-		reply.Responses = append(reply.Responses, &structs.KeyringResponse{
+		if err != nil {
-			Datacenter: m.srv.config.Datacenter,
+			return err
-			Messages:   respWAN.Messages,
+		}
-			Keys:       respWAN.Keys,
+		m.ingestKeyringResponse(respWAN, reply)
-			NumResp:    respWAN.NumResp,
-			NumNodes:   respWAN.NumNodes,
-			NumErr:     respWAN.NumErr,
-		})
 
-		// Mark key rotation as being already forwarded, then forward.
 		args.Forwarded = true
 		return m.srv.forwardAll("Internal.RemoveKey", args, reply)
 	}

consul/rpc.go

@@ -227,9 +227,10 @@ func (s *Server) forwardDC(method, dc string, args interface{}, reply interface{
 func (s *Server) forwardAll(method string, args, reply interface{}) error {
 	for dc, _ := range s.remoteConsuls {
 		if dc != s.config.Datacenter {
-			if err := s.forwardDC(method, dc, args, reply); err != nil {
+			// Forward the RPC call. Even if an error is returned here, we still
-				return err
+			// want to continue broadcasting to the remaining DC's to avoid
-			}
+			// network partitions completely killing us.
+			go s.forwardDC(method, dc, args, reply)
 		}
 	}
 	return nil