agent: Adding support for statsite telemetry

command/agent/command.go

@@ -59,6 +59,7 @@ func (c *Command) readConfig() *Config {
 	cmdFlags.StringVar(&cmdConfig.DNSAddr, "dns-addr", "", "address to bind dns server to")
 	cmdFlags.BoolVar(&cmdConfig.Server, "server", false, "run agent as server")
 	cmdFlags.BoolVar(&cmdConfig.Bootstrap, "bootstrap", false, "enable server bootstrap mode")
+	cmdFlags.StringVar(&cmdConfig.StatsiteAddr, "statsite", "", "address of statsite instance")
 	if err := cmdFlags.Parse(c.args); err != nil {
 		return nil
 	}
@@ -195,8 +196,21 @@ func (c *Command) Run(args []string) int {
 	inm := metrics.NewInmemSink(10*time.Second, time.Minute)
 	metrics.DefaultInmemSignal(inm)
 	metricsConf := metrics.DefaultConfig("consul")
-	metricsConf.EnableHostname = false
+
-	metrics.NewGlobal(metricsConf, inm)
+	// Optionally configure a statsite sink if provided
+	if config.StatsiteAddr != "" {
+		sink, err := metrics.NewStatsiteSink(config.StatsiteAddr)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Failed to start statsite sink. Got: %s", err))
+			return 1
+		}
+		fanout := metrics.FanoutSink{inm, sink}
+		metrics.NewGlobal(metricsConf, fanout)
+
+	} else {
+		metricsConf.EnableHostname = false
+		metrics.NewGlobal(metricsConf, inm)
+	}
 
 	// Create the agent
 	if err := c.setupAgent(config, logOutput, logWriter); err != nil {

command/agent/config.go

@@ -93,6 +93,10 @@ type Config struct {
 	// the INT signal. Defaults false. This can be changed on reload.
 	SkipLeaveOnInt bool `mapstructure:"skip_leave_on_interrupt"`
 
+	// StatsiteAddr is the address of a statsite instance. If provided,
+	// metrics will be streamed to that instance.
+	StatsiteAddr string `mapstructure:"statsite_addr"`
+
 	// Checks holds the provided check definitions
 	Checks []*CheckDefinition `mapstructure:"-"`
 

website/source/docs/agent/options.html.markdown

@@ -114,6 +114,10 @@ The options below are all specified on the command-line.
   nodes are able to self-elect. Once there are multiple servers in a datacenter, it is generally a good idea
   to disable bootstrap mode on all of them.
 
+* `-statsite` - This flag provides the address of a statsite instance. If provided Consul will stream
+  various telemetry information to that instance for aggregation. This can be used to capture various
+  runtime information.
+
 ## Configuration Files
 
 In addition to the command-line options, configuration can be put into
@@ -194,3 +198,5 @@ They are documented seperately under [check configuration](/docs/agent/checks.ht
   gracefully leave, but setting this to true disables that. Defaults to false.
   Interrupts are usually from a Control-C from a shell.
 
+* `statsite_addr` - Equivalent to the `-statsite` command-line flag.
+