Expose ClusterName instead of Banner/StatePath

cluster/cluster.go

@@ -19,21 +19,21 @@ const KeyLen = 32
 
 // Cluster represents a running cluster configuration
 type Cluster struct {
+	name      string
 	ml        *memberlist.Memberlist
 	mlConfig  *memberlist.Config
 	localNode *common.Node
 	LocalName string
-	statePath string
 	state     *state
 	events    chan memberlist.NodeEvent
 }
 
 // New is used to create a new Cluster instance
 // The returned instance is ready to be updated with the local node settings then joined
-func New(init bool, clusterKey []byte, bindAddr string, bindPort int, statePath string, useIPAsName bool) (*Cluster, error) {
+func New(name string, init bool, clusterKey []byte, bindAddr string, bindPort int, useIPAsName bool) (*Cluster, error) {
 	state := &state{}
 	if !init {
-		loadState(state, statePath)
+		loadState(state, name)
 	}
 
 	clusterKey, err := computeClusterKey(state, clusterKey)
@@ -57,14 +57,14 @@ func New(init bool, clusterKey []byte, bindAddr string, bindPort int, statePath
 	}
 
 	cluster := Cluster{
+		name:      name,
 		ml:        ml,
 		mlConfig:  mlConfig,
 		LocalName: ml.LocalNode().Name,
 		// The big channel buffer is a work-around for https://github.com/hashicorp/memberlist/issues/23
 		// More than this many simultaneous events will deadlock cluster.members()
-		events:    make(chan memberlist.NodeEvent, 100),
-		state:     state,
-		statePath: statePath,
+		events: make(chan memberlist.NodeEvent, 100),
+		state:  state,
 	}
 	return &cluster, nil
 }
@@ -96,7 +96,7 @@ func (c *Cluster) Join(addrs []string) error {
 
 // Leave saves the current state before leaving, then leaves the cluster
 func (c *Cluster) Leave() {
-	c.state.save(c.statePath)
+	c.state.save(c.name)
 	c.ml.Leave(10 * time.Second)
 	c.ml.Shutdown() //nolint: errcheck
 }
@@ -146,7 +146,7 @@ func (c *Cluster) Members() <-chan []common.Node {
 			}
 			c.state.Nodes = nodes
 			changes <- nodes
-			c.state.save(c.statePath)
+			c.state.save(c.name)
 		}
 	}()
 	return changes

cluster/state.go

@@ -2,6 +2,7 @@ package cluster
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
@@ -16,12 +17,10 @@ type state struct {
 	Nodes      []common.Node
 }
 
-const defaultStatePath = "/var/lib/wesher/state.json"
+var defaultStatePath = "/var/lib/wesher/%s.json"
 
-func (s *state) save(statePath string) error {
-	if statePath == "" {
-		statePath = defaultStatePath
-	}
+func (s *state) save(clusterName string) error {
+	statePath := fmt.Sprintf(defaultStatePath, clusterName)
 	if err := os.MkdirAll(path.Dir(statePath), 0700); err != nil {
 		return err
 	}
@@ -34,10 +33,8 @@ func (s *state) save(statePath string) error {
 	return ioutil.WriteFile(statePath, stateOut, 0600)
 }
 
-func loadState(cs *state, statePath string) {
-	if statePath == "" {
-		statePath = defaultStatePath
-	}
+func loadState(cs *state, clusterName string) {
+	statePath := fmt.Sprintf(defaultStatePath, clusterName)
 	content, err := ioutil.ReadFile(statePath)
 	if err != nil {
 		if !os.IsNotExist(err) {

cluster/state_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func Test_state_save_soad(t *testing.T) {
-	statePath := "/tmp/wesher.json"
+	defaultStatePath = "/tmp/%s.json"
 	key := "abcdefghijklmnopqrstuvwxyzABCDEF"
 	node := common.Node{
 		Name: "node",
@@ -23,11 +23,11 @@ func Test_state_save_soad(t *testing.T) {
 		},
 	}
 
-	if err := cluster.state.save(statePath); err != nil {
+	if err := cluster.state.save("test"); err != nil {
 		t.Error(err)
 	}
 	loaded := &state{}
-	loadState(loaded, statePath)
+	loadState(loaded, "test")
 
 	if !reflect.DeepEqual(cluster.state, loaded) {
 		t.Errorf("cluster state save then reload mistmatch: %s / %s", cluster.state, loaded)

config.go

@@ -14,8 +14,7 @@ type config struct {
 	ClusterKey    []byte   `id:"cluster-key" desc:"shared key for cluster membership; must be 32 bytes base64 encoded; will be generated if not provided"`
 	Join          []string `desc:"comma separated list of hostnames or IP addresses to existing cluster members; if not provided, will attempt resuming any known state or otherwise wait for further members."`
 	Init          bool     `desc:"whether to explicitly (re)initialize the cluster; any known state from previous runs will be forgotten"`
-	Banner        string   `id:"banner" desc:"a string appended to /etc/hosts banner to discriminate between multiple running clusters"`
-	StatePath     string   `id:"state-path" desc:"path where the cluster state is stored; optional, depends on cluster name if not set"`
+	ClusterName   string   `id:"cluster-name" desc:"identifier for the wesher cluster; can be used to peer with multiple clusters" default:"default"`
 	BindAddr      string   `id:"bind-addr" desc:"IP address to bind to for cluster membership traffic (cannot be used with --bind-iface)"`
 	BindIface     string   `id:"bind-iface" desc:"Interface to bind to for cluster membership traffic (cannot be used with --bind-addr)"`
 	ClusterPort   int      `id:"cluster-port" desc:"port used for membership gossip traffic (both TCP and UDP); must be the same across cluster" default:"7946"`

main.go

@@ -35,7 +35,7 @@ func main() {
 	logrus.SetLevel(logLevel)
 
 	// Create the wireguard and cluster configuration
-	cluster, err := cluster.New(config.Init, config.ClusterKey, config.BindAddr, config.ClusterPort, config.StatePath, config.UseIPAsName)
+	cluster, err := cluster.New(config.ClusterName, config.Init, config.ClusterKey, config.BindAddr, config.ClusterPort, config.UseIPAsName)
 	if err != nil {
 		logrus.WithError(err).Fatal("could not create cluster")
 	}
@@ -46,7 +46,7 @@ func main() {
 
 	// Prepare the /etc/hosts writer
 	hostsFile := &etchosts.EtcHosts{
-		Banner: "# ! managed automatically by wesher " + config.Banner,
+		Banner: "# ! managed automatically by wesher " + config.ClusterName,
 		Logger: logrus.StandardLogger(),
 	}
 

tests/e2e.sh

@@ -101,8 +101,8 @@ test_cluster_simultaneous_start() {
 }
 
 test_multiple_clusters_restart() {
-    cluster1='--cluster-port 7946 --wireguard-port 51820 --banner cluster1 --state-path /var/lib/wesher/cluster1.json --interface wgoverlay --overlay-net 10.10.0.0/16'
-    cluster2='--cluster-port 7947 --wireguard-port 51821 --banner cluster2 --state-path /var/lib/wesher/cluster2.json --interface wgoverlay2 --overlay-net 10.11.0.0/16'
+    cluster1='--cluster-port 7946 --wireguard-port 51820 --cluster-name cluster1 --interface wgoverlay --overlay-net 10.10.0.0/16'
+    cluster2='--cluster-port 7947 --wireguard-port 51821 --cluster-name cluster2 --interface wgoverlay2 --overlay-net 10.11.0.0/16'
     setup_wireguard='wireguard-go wgoverlay2 2>/dev/null >/dev/null'
     join_cluster2="nohup /app/wesher --cluster-key 'ILICZ3yBMCGAWNIq5Pn0bewBVimW3Q2yRVJ/Be+b1Uc=' --join test2-orig $cluster2 2>/dev/null &"