Initial ctx for publishers implemented

example/toShip1-REQPing.json

@@ -2,7 +2,7 @@
     {
         "directory": "ping",
         "fileExtension":".ping.log",
-        "toNode": "ship1",
+        "toNode": "ship2",
         "data": [""],
         "method":"REQPing",
         "timeout":3,

process.go

@@ -2,6 +2,7 @@ package steward
 
 import (
 	"bytes"
+	"context"
 	"encoding/gob"
 	"fmt"
 	"log"
@@ -60,6 +61,10 @@ type process struct {
 	processes *processes
 	// nats connection
 	natsConn *nats.Conn
+	// context
+	ctx context.Context
+	// context cancelFunc
+	ctxCancel context.CancelFunc
 }
 
 // prepareNewProcess will set the the provided values and the default
@@ -74,6 +79,8 @@ func newProcess(natsConn *nats.Conn, processes *processes, toRingbufferCh chan<-
 		m[a] = struct{}{}
 	}
 
+	ctx, cancel := context.WithCancel(context.Background())
+
 	var method Method
 
 	proc := process{
@@ -89,6 +96,8 @@ func newProcess(natsConn *nats.Conn, processes *processes, toRingbufferCh chan<-
 		configuration:    configuration,
 		processes:        processes,
 		natsConn:         natsConn,
+		ctx:              ctx,
+		ctxCancel:        cancel,
 	}
 
 	return proc
@@ -366,9 +375,17 @@ func (p process) subscribeMessages() {
 func (p process) publishMessages(natsConn *nats.Conn, processes *processes) {
 	for {
 		var err error
+		var m Message
 
-		// Wait and read the next message on the message channel
-		m := <-p.subject.messageCh
+		// Wait and read the next message on the message channel, or
+		// exit this function if Cancel are received via ctx.
+		select {
+		case m = <-p.subject.messageCh:
+		case <-p.ctx.Done():
+			er := fmt.Errorf("info: canceling publisher: %v", p.subject.name())
+			sendErrorLogMessage(p.toRingbufferCh, node(p.node), er)
+			return
+		}
 
 		// Get the process name so we can look up the process in the
 		// processes map, and increment the message counter.