Check if service exists before trying to manipulate it

Author: jhkolb

spawnclient/client.go

@@ -89,8 +89,8 @@ func (sc *Client) Inspect(uri string) (*daemon.Heartbeat, map[string]daemon.Serv
 		daemonHb = hb
 	}
 
-	svcClient := sc.bwClient.RegisterService(uri, "s.spawnpoint")
-	iFaceClient := svcClient.RegisterInterface("+", "i.spawnable")
+	svcClient := sc.bwClient.NewServiceClient(uri, "s.spawnpoint")
+	iFaceClient := svcClient.AddInterface("+", "i.spawnable")
 	svcHeartbeatMsgs, err := sc.bwClient.Query(&bw2.QueryParams{
 		URI: iFaceClient.SignalURI("heartbeat"),
 	})

spawnctl/main.go

@@ -18,7 +18,7 @@ import (
 )
 
 const deploymentHistVar = "SPAWNCTL_HISTORY_FILE"
-const healthHorizon = 5 * time.Minute
+const healthHorizon = 2 * time.Minute
 
 func main() {
 	app := cli.NewApp()
@@ -344,6 +344,18 @@ func manipulateService(c *cli.Context, command string) error {
 		fmt.Printf("Last seen %s ago\n", age.String())
 		os.Exit(1)
 	}
+	age, err = checkServiceHealth(spawnClient, spawnpointURI, svcName)
+	if err != nil {
+		fmt.Printf("Failed to check service health: %s\n", err)
+		os.Exit(1)
+	} else if age == 0 {
+		fmt.Printf("Service %s does not exist at spawnpoint %s\n", svcName, spawnpointURI)
+		os.Exit(1)
+	} else if age > healthHorizon {
+		fmt.Printf("Service %s is not running\n", svcName)
+		fmt.Printf("Last seen %s ago\n", age.String())
+		os.Exit(1)
+	}
 
 	var ctx context.Context
 	var cancel context.CancelFunc
@@ -490,3 +502,17 @@ func checkSpawnpointHealth(sc *spawnclient.Client, uri string) (time.Duration, e
 	duration := time.Now().Sub(daemonTimestamp)
 	return duration, nil
 }
+
+func checkServiceHealth(sc *spawnclient.Client, uri string, svcName string) (time.Duration, error) {
+	_, svcHbs, err := sc.Inspect(uri)
+	if err != nil {
+		return 0, errors.Wrap(err, "Failed to inspect spawnpoint")
+	}
+	svcHb, ok := svcHbs[svcName]
+	if !ok {
+		return 0, nil
+	}
+	svcTimestamp := time.Unix(0, svcHb.Time)
+	duration := time.Now().Sub(svcTimestamp)
+	return duration, nil
+}