Agency size 1

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()

test/docker_cluster_local_test.go

@@ -86,6 +86,65 @@ func TestDockerClusterLocal(t *testing.T) {
 	ShutdownStarter(t, insecureStarterEndpoint(0))
 }
 
+// TestDockerClusterLocalAgencySize1 runs the arangodb starter in docker
+// with `--starter.local` & `--cluster.agency-size=1`
+func TestDockerClusterLocalAgencySize1(t *testing.T) {
+	needTestMode(t, testModeDocker)
+	needStarterMode(t, starterModeCluster)
+	if os.Getenv("IP") == "" {
+		t.Fatal("IP envvar must be set to IP address of this machine")
+	}
+	/*
+		docker volume create arangodb1
+		docker run -i --name=adb1 --rm -p 8528:8528 \
+			-v arangodb1:/data \
+			-v /var/run/docker.sock:/var/run/docker.sock \
+			arangodb/arangodb-starter \
+			--docker.container=adb1 \
+			--starter.address=$IP \
+			--starter.local \
+			--cluster.agency-size=1
+	*/
+	volID := createDockerID("vol-starter-test-local-cluster-as1-")
+	createDockerVolume(t, volID)
+	defer removeDockerVolume(t, volID)
+
+	// Cleanup of left over tests
+	removeDockerContainersByLabel(t, "starter-test=true")
+	removeStarterCreatedDockerContainers(t)
+
+	start := time.Now()
+
+	cID := createDockerID("starter-test-local-cluster-as1-")
+	dockerRun := Spawn(t, strings.Join([]string{
+		"docker run -i",
+		"--label starter-test=true",
+		"--name=" + cID,
+		"--rm",
+		fmt.Sprintf("-p %d:%d", basePort, basePort),
+		fmt.Sprintf("-v %s:/data", volID),
+		"-v /var/run/docker.sock:/var/run/docker.sock",
+		"arangodb/arangodb-starter",
+		"--docker.container=" + cID,
+		"--starter.address=$IP",
+		"--starter.local",
+		"--cluster.agency-size=1",
+		createEnvironmentStarterOptions(),
+	}, " "))
+	defer dockerRun.Close()
+	defer removeDockerContainer(t, cID)
+
+	if ok := WaitUntilStarterReady(t, whatCluster, dockerRun); ok {
+		t.Logf("Cluster start took %s", time.Since(start))
+		testCluster(t, insecureStarterEndpoint(0), false)
+	}
+
+	if isVerbose {
+		t.Log("Waiting for termination")
+	}
+	ShutdownStarter(t, insecureStarterEndpoint(0))
+}
+
 // TestOldDockerClusterLocal runs the arangodb starter in docker with `--local`
 func TestOldDockerClusterLocal(t *testing.T) {
 	needTestMode(t, testModeDocker)