switch node names to machine ID

internal/flypg/node.go

@@ -297,10 +297,10 @@ func (n *Node) PostInit(ctx context.Context) error {
 			}
 
 			// This should never happen
-			if primary != n.PrivateIP {
+			if primary != n.RepMgr.machineIdToDNS(n.MachineID) {
 				return fmt.Errorf("resolved primary '%s' does not match ourself '%s'. this should not happen",
 					primary,
-					n.PrivateIP,
+					n.RepMgr.machineIdToDNS(n.MachineID),
 				)
 			}
 

internal/flypg/repmgr.go

@@ -329,7 +329,7 @@ func (r *RepMgr) regenReplicationConf(ctx context.Context) error {
 	// TODO: do we need -c?
 	if _, err := utils.RunCmd(ctx, "postgres",
 		"repmgr", "--replication-conf-only",
-		"-h", r.PrivateIP,
+		"-h", "",
 		"-p", fmt.Sprint(r.Port),
 		"-d", r.DatabaseName,
 		"-U", r.Credentials.Username,

internal/flypg/zombie.go

@@ -84,7 +84,7 @@ type DNASample struct {
 
 func TakeDNASample(ctx context.Context, node *Node, standbys []Member) (*DNASample, error) {
 	sample := &DNASample{
-		hostname:       node.PrivateIP,
+		hostname:       node.RepMgr.machineIdToDNS(node.MachineID),
 		totalMembers:   len(standbys) + 1,
 		totalActive:    1,
 		totalInactive:  0,
@@ -117,7 +117,8 @@ func TakeDNASample(ctx context.Context, node *Node, standbys []Member) (*DNASamp
 		sample.totalActive++
 
 		// Record conflict when primary doesn't match.
-		if primary.Hostname != node.MachineID && primary.Hostname != node.PrivateIP {
+		// We're checking PrivateIP here for backwards compatibility
+		if primary.Hostname != node.RepMgr.machineIdToDNS(node.MachineID) && primary.Hostname != node.PrivateIP {
 			sample.totalConflicts++
 			sample.conflictMap[primary.Hostname]++
 		}