consul: Gossip the build using Serf

command/agent/agent.go

@@ -175,6 +175,14 @@ func (a *Agent) consulConfig() *consul.Config {
 		base.ProtocolVersion = uint8(a.config.Protocol)
 	}
 
+	// Format the build string
+	revision := a.config.Revision
+	if len(revision) > 8 {
+		revision = revision[:8]
+	}
+	base.Build = fmt.Sprintf("%s%s:%s",
+		a.config.Version, a.config.VersionPrerelease, revision)
+
 	// Copy the TLS configuration
 	base.VerifyIncoming = a.config.VerifyIncoming
 	base.VerifyOutgoing = a.config.VerifyOutgoing

consul/client.go

@@ -128,6 +128,7 @@ func (c *Client) setupSerf(conf *serf.Config, ch chan serf.Event, path string) (
 	conf.Tags["vsn"] = fmt.Sprintf("%d", c.config.ProtocolVersion)
 	conf.Tags["vsn_min"] = fmt.Sprintf("%d", ProtocolVersionMin)
 	conf.Tags["vsn_max"] = fmt.Sprintf("%d", ProtocolVersionMax)
+	conf.Tags["build"] = c.config.Build
 	conf.MemberlistConfig.LogOutput = c.config.LogOutput
 	conf.LogOutput = c.config.LogOutput
 	conf.EventCh = ch

consul/config.go

@@ -115,6 +115,10 @@ type Config struct {
 	// true, we ignore the leave, and rejoin the cluster on start.
 	RejoinAfterLeave bool
 
+	// Build is a string that is gossiped around, and can be used to help
+	// operators track which versions are actively deployed
+	Build string
+
 	// ServerUp callback can be used to trigger a notification that
 	// a Consul server is now up and known about.
 	ServerUp func()

consul/server.go

@@ -224,6 +224,7 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, w
 	conf.Tags["vsn"] = fmt.Sprintf("%d", s.config.ProtocolVersion)
 	conf.Tags["vsn_min"] = fmt.Sprintf("%d", ProtocolVersionMin)
 	conf.Tags["vsn_max"] = fmt.Sprintf("%d", ProtocolVersionMax)
+	conf.Tags["build"] = s.config.Build
 	conf.Tags["port"] = fmt.Sprintf("%d", addr.Port)
 	if s.config.Bootstrap {
 		conf.Tags["bootstrap"] = "1"