feat: add static discovery provider (#72)

* feat: add static discovery provider
* fix: data race

cluster/cluster.go

@@ -25,8 +25,6 @@ import (
 )
 
 const (
-	clientPortName     = "clients-port"
-	peersPortName      = "peers-port"
 	memberAddThreshold = 5
 )
 
@@ -102,7 +100,7 @@ func (c *Cluster) Start(ctx context.Context) error {
 		for _, discoNode := range discoNodes {
 			if !(hostNode.host == discoNode.Host) {
 				// build the peer URL
-				_, clientsURL := nodeURLs(discoNode)
+				_, clientsURL := discoNode.URLs()
 				// set the endpoints
 				existingEndpoints = append(existingEndpoints, clientsURL)
 			}
@@ -170,7 +168,7 @@ func (c *Cluster) Start(ctx context.Context) error {
 	endpoints := make([]string, len(discoNodes))
 	for i, discoNode := range discoNodes {
 		// build the peer URL
-		peersURL, clientsURL := nodeURLs(discoNode)
+		peersURL, clientsURL := discoNode.URLs()
 		// build the initial cluster builder
 		initialPeerURLs[i] = fmt.Sprintf("%s=%s", discoNode.Name, peersURL)
 		// set the endpoints
@@ -346,7 +344,7 @@ func (c *Cluster) handleClusterEvents(events <-chan discovery.Event) {
 						// when matching member is found
 						if member != nil {
 							// grab the latest URLs
-							peerURL, clientURL := nodeURLs(latest)
+							peerURL, clientURL := latest.URLs()
 							// create an instance of member and set the various URLs
 							m := &etcdserverpb.Member{
 								ID:         member.GetID(),
@@ -401,9 +399,9 @@ func (c *Cluster) whoami(discoNodes []*discovery.Node) *hostNode {
 		// here the host node is found
 		if slices.Contains(addresses, discoNode.Host) {
 			// get the peer port
-			peersPort := discoNode.Ports[peersPortName]
+			peersPort := discoNode.PeersPort()
 			// get the clients port
-			clientsPort := discoNode.Ports[clientPortName]
+			clientsPort := discoNode.ClientsPort()
 
 			// let us build the host peer URLs and getClient URLs
 			peerURLs := goset.NewSet[string]()
@@ -458,7 +456,7 @@ func (c *Cluster) discoverNodes(ctx context.Context) []*discovery.Node {
 				// remove duplicate
 				for _, discoNode := range discoNodes {
 					// let us get the node URL
-					peersURL, _ := nodeURLs(discoNode)
+					peersURL, _ := discoNode.URLs()
 					// check whether the Cluster has been already discovered and ignore it
 					if _, ok := seen[peersURL]; ok {
 						continue
@@ -484,16 +482,10 @@ func (c *Cluster) discoverNodes(ctx context.Context) []*discovery.Node {
 	return nodes
 }
 
-// nodeURLs returns the actual node URLs
-func nodeURLs(node *discovery.Node) (peersURL string, clientURL string) {
-	return fmt.Sprintf("http://%s:%d", node.Host, node.Ports[peersPortName]),
-		fmt.Sprintf("http://%s:%d", node.Host, node.Ports[clientPortName])
-}
-
 // locateMember helps find a given member using its peerURL
 func locateMember(members []*etcdserverpb.Member, node *discovery.Node) *etcdserverpb.Member {
 	// grab the given node URL
-	peerURL, _ := nodeURLs(node)
+	peerURL, _ := node.URLs()
 	for _, member := range members {
 		if slices.Contains(member.GetPeerURLs(), peerURL) && member.GetName() == node.Name {
 			return member