Fix startup issues and add pinging config peer.

main.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"flag"
 	"net"
 	"net/http"
 	"os"
@@ -20,6 +19,7 @@ const GroupStatePrimaryAlone = "wait-primary"
 const GroupStateStandby = "secondary"
 const DefaultFormation = "default"
 const DefaultSocketPath = "/var/run/pg_autoconfig.sock"
+const CyclesPerPing = 10
 
 type postgresInstance struct {
 	// Locally available info
@@ -67,9 +67,11 @@ type pgpoolInstance struct {
 	IsReadOnly bool
 }
 
-func main() {
-	flag.Parse()
+type pgpoolPingMessage struct {
+	NeedsConfig bool
+}
 
+func main() {
 	// Logging
 	var logLevelS string
 	if logLevelS = os.Getenv("AUTOCONFIG_LOG_LEVEL"); logLevelS == "" {
@@ -90,8 +92,8 @@ func main() {
 	socketPath := DefaultSocketPath
 	nextIsFormation := false
 	formation := DefaultFormation
-	var argsLeft []string
-	for i, j := range os.Args {
+	argsLeft := os.Args[1:]
+	for i, j := range argsLeft {
 		if nextIsType {
 			nextIsType = false
 			switch j {
@@ -107,7 +109,8 @@ func main() {
 			nextIsFormation = false
 			formation = j
 		} else if j == "--" {
-			argsLeft = os.Args[i+1:]
+			argsLeft = argsLeft[i+1:]
+			break
 		} else {
 			switch j {
 			case "--type":
@@ -166,6 +169,7 @@ func main() {
 			},
 		}
 
+		pingWaitCounter := 0
 		for !doComplete {
 			cmdFormationState := exec.Command("/usr/bin/pg_autoctl", "show", "state", "--formation", formation, "--json")
 			cmdFormationState.Env = os.Environ()
@@ -220,6 +224,25 @@ func main() {
 				}
 			}
 
+			// Send a periodic ping to the configuration worker
+			if pingWaitCounter == CyclesPerPing {
+				pingWaitCounter = 0
+				if response, err := httpc.Get("http://unix/ping"); err != nil {
+					log.WithError(err).WithFields(log.Fields{"response": response}).Trace("Failed to ping to the peer process.")
+				} else {
+					var msg pgpoolPingMessage
+					if err := json.NewDecoder(response.Body).Decode(&msg); err != nil {
+						log.WithError(err).Warn("Failed to decode ping response.")
+					} else {
+						if msg.NeedsConfig {
+							if response, err := httpc.Post("http://unix/config", "application/octet-stream", bytes.NewReader(lastSentStateJson)); err != nil {
+								log.WithError(err).WithFields(log.Fields{"response": response}).Warn("Failed to send configuration to the peer process.")
+							}
+						}
+					}
+				}
+			}
+
 			time.Sleep(1000 * time.Millisecond)
 		}
 	}()
@@ -228,6 +251,8 @@ func main() {
 	log.WithFields(log.Fields{"name": argsLeft[0], "args": argsLeft[1:]}).Info("Handling over to inner process.")
 	cmd := exec.Command(argsLeft[0], argsLeft[1:]...)
 	cmd.Env = os.Environ()
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
 	cmd.Run()
 
 	log.Info("pg_auto_failover load balancer has completed.")