Broker Id should be updated when streamed

[GavinDmello]

Related to #96
@mcollina @nguyenthenguyen Please verify

[coveralls]

Coverage increased (+0.004%) to 97.42% when pulling 3d49536 on fixBrokerId into 3f8d6a7 on master.

[nguyenthenguyen]

I have tested but not fix will problems. I have 1 aedes instance:
Step 1: aedes start with id1: HJmwY81Te
Step 2: All client connect to server id1 HJmwY81Te
Step 3: Client subcribe will topic testdevice/status to server id1 HJmwY81Te
Step 4: aedes restart with id2: XmmkY21xj for some reason, ex: server crash ...
Step 5: All client reconnect to server id2 XmmkY21xj
Step 6: Client subcribe will topic testdevice/status to server id2 XmmkY21xj
Step 7: server id2 XmmkY21xj start clean will https://github.com/mcollina/aedes/blob/master/aedes.js#L80
Step 8: All will topic get from persistence with old id1 HJmwY81Te process by https://github.com/mcollina/aedes/blob/master/aedes.js#L92
Step 9: needsPublishing function set to true by https://github.com/mcollina/aedes/blob/master/aedes.js#L94
Step 10: server id2 XmmkY21xj publish will https://github.com/mcollina/aedes/blob/master/aedes.js#L104
Step 11: server id2 not delete old will by https://github.com/mcollina/aedes/blob/master/aedes.js#L109
because that.persistence.delWill will use id2 not id1
-> Bug: When server with id2 start _clearWillInterval will publish all will topic of id1 but all client is online not offline

[mcollina]

can you send a PR with a broken unit test that reproduces this error? Looking at the code, it seems correct, as the following sentence is not correct:

because that.persistence.delWill will use id2 not id1

it uses the client id, not the broker id.

[nguyenthenguyen]

@mcollina Thanks!
But now, I'm not find a solution for this
that.persistence.delWill use broker id and client id? Ex: redis persistence
https://github.com/mcollina/aedes-persistence-redis/blob/master/persistence.js#L510

[GavinDmello]

@nguyenthenguyen @mcollina The old will is not being deleted. That's one issue.
@nguyenthenguyen What did you mean by will publish all will topic of id1 but all client is online not offline. I didn't quite understand

[mcollina]

@nguyenthenguyen I have reverted this change, as it was probably not correct (my bad). Can you please upload a script to reproduce the issue you are facing using MQTT.js or just mqtt-connection?

[nguyenthenguyen]

@mcollina @GavinDmello Thanks!
Step 1: Start server.js
Step 2: start client1.js
Step 3: start client2.js
Step 4: stop server.js
Step 5: start server.js
Step 6: See client2.js log

server.js

var redisPersistence = require('aedes-persistence-redis');
var aedes = require('aedes')({
    persistence: redisPersistence({
	    "port": 6379,          
		"host": "127.0.0.1",
		"family": 4,
		"password": "",
		"db": 1
    }),
    heartbeatInterval: 1000 // more fast to test
});

var mqttServer = require('net').createServer(aedes.handle);

var mqttPort = 1883
mqttServer.listen(mqttPort,"0.0.0.0", function () {
  console.log('mqtt server listening on port', mqttPort)
});

client1.js

var mqtt = require('mqtt')
var client  = mqtt.connect('mqtt://localhost:1883',{
    will:{
        topic:"client1/status",
        payload: "client1 offline",
        qos: 0,
        retain: true
    }
})

client.on('connect', function () {
    console.log("Client 1 connected")
    client.publish('client1/status', 'client1 online')
})

client.on('message', function (topic, message) {
  console.log(message.toString())
})

client2.js

var mqtt = require('mqtt')
var client  = mqtt.connect('mqtt://localhost:1883',{
    will:{
        topic:"client2/status",
        payload: "client2 offline",
        qos: 0,
        retain: true
    }
})

client.on('connect', function () {
    console.log("Client 2 connected")
    client.subscribe('client1/status')
})

client.on('message', function (topic, message) {
  console.log(message.toString())
})

[GavinDmello]

@nguyenthenguyen Wills aren't getting deleted because the brokerId is old, so you're getting it on every heartbeat.
@mcollina Can we pass the brokerId to the delWill function ?

[mcollina]

@GavinDmello I think we might update the will (putWill) before sending it, so all of this would actually work.

[GavinDmello]

If brokerId is not the same, del the old will and put the new one and then publish ?

[mcollina]

we can just do putWill, as that should overwrite the previous value, then publish, then delete.
However, we might have to fix some of the persistences, i.e. pass in the brokerId as you said.

[GavinDmello]

@mcollina Yea. We'll have to pass those brokerIds to delWill.
@nguyenthenguyen Sorry about this. Didn't quite understand the issue at first.