implemented a basic discovery loop

swarm.go

@@ -6,6 +6,7 @@ import (
  "fmt"
  "io/ioutil"
  "net"
+ "time"
 
  "github.com/docker/docker/api/types"
  "github.com/docker/docker/api/types/filters"
@@ -16,6 +17,7 @@ import (
 )
 
 var prometheusService string
+var discoveryInterval int
 
 // allocateIP returns the 3rd last IP in the network range.
 func allocateIP(netCIDR *net.IPNet) string {
@@ -109,8 +111,7 @@ type scrapeTarget struct {
  Labels map[string]string
 }
 
-func discoverSwarm(cmd *cobra.Command, args []string) {
- findPrometheusContainer(prometheusService)
+func discoverSwarm() {
  cli, err := client.NewEnvClient()
  if err != nil {
  panic(err)
@@ -159,15 +160,23 @@ func discoverSwarm(cmd *cobra.Command, args []string) {
  writeSDConfig(scrapeTargets)
 }
 
+func discoveryProcess(cmd *cobra.Command, args []string) {
+ for {
+ discoverSwarm()
+ time.Sleep(time.Duration(discoveryInterval) * time.Second)
+ }
+}
+
 func main() {
 
  var cmdDiscover = &cobra.Command{
  Use: "discover",
  Short: "Starts Swarm service discovery",
- Run: discoverSwarm,
+ Run: discoveryProcess,
  }
 
  cmdDiscover.Flags().StringVarP(&prometheusService, "prometheus", "p", "prometheus", "Name of the Prometheus service")
+ cmdDiscover.Flags().IntVarP(&discoveryInterval, "interval", "i", 30, "The interval, in seconds, at which the discovery process is kicked off")
 
  var rootCmd = &cobra.Command{Use: "promswarm"}
  rootCmd.AddCommand(cmdDiscover)