Support --cluster.agency-size=1 combined with --starter.local

Author: ewoutp

service/bootstrap_config.go

@@ -69,3 +69,20 @@ func (bsCfg BootstrapConfig) CreateTLSConfig() (*tls.Config, error) {
 		Certificates: []tls.Certificate{cert},
 	}, nil
 }
+
+// PeersNeeded returns the minimum number of peers needed for the given config.
+func (bsCfg BootstrapConfig) PeersNeeded() int {
+	minServers := 1
+	switch bsCfg.Mode {
+	case ServiceModeCluster:
+		minServers = 3
+	case ServiceModeSingle:
+		minServers = 1
+	case ServiceModeResilientSingle:
+		minServers = 2
+	}
+	if minServers < bsCfg.AgencySize {
+		minServers = bsCfg.AgencySize
+	}
+	return minServers
+}

service/bootstrap_master.go

@@ -61,7 +61,17 @@ func (s *Service) bootstrapMaster(ctx context.Context, runner Runner, config Con
 	// Permanent loop:
 	s.log.Infof("Serving as master with ID '%s' on %s:%d...", s.id, config.OwnAddress, s.announcePort)
 
-	if s.mode.IsSingleMode() || s.myPeers.HaveEnoughAgents() {
+	// Can we start right away?
+	needMorePeers := true
+	if s.mode.IsSingleMode() {
+		needMorePeers = false
+	} else if !s.myPeers.HaveEnoughAgents() {
+		needMorePeers = true
+	} else if bsCfg.StartLocalSlaves {
+		peersNeeded := bsCfg.PeersNeeded()
+		needMorePeers = len(s.myPeers.AllPeers) < peersNeeded
+	}
+	if !needMorePeers {
 		// We have all the agents that we need, start a single server/cluster right now
 		s.saveSetup()
 		s.log.Info("Starting service...")

service/local_slaves.go

@@ -33,8 +33,9 @@ import (
 
 // createAndStartLocalSlaves creates additional peers for local slaves and starts services for them.
 func (s *Service) createAndStartLocalSlaves(wg *sync.WaitGroup, config Config, bsCfg BootstrapConfig) {
-	peers := make([]Peer, 0, bsCfg.AgencySize)
-	for index := 2; index <= bsCfg.AgencySize; index++ {
+	peersNeeded := bsCfg.PeersNeeded()
+	peers := make([]Peer, 0, peersNeeded)
+	for index := 2; index <= peersNeeded; index++ {
 		p := Peer{}
 		var err error
 		p.ID, err = createUniqueID()