New

Serializers for transporters #10

Implemented pluggable serializers.
Built-in serializers:

• JSON (default)
• Avro
• MsgPack
• ProtoBuf

Usage

let JSONSerializer = require("moleculer").Serializers.JSON;

let broker = new ServiceBroker({
	serializer: new JSONSerializer(),
	transporter: new Transporter(),
	nodeID: "node-1"	
});

Typescript definition file #5

Created an index.d.ts file. I'm not familiar in Typescript, so if you found error please help me and open a PR with fix. Thank you!

Metrics rate option

Added metricsRate options to broker. This property sets the rate of sampled calls.

• 1 means to metric all calls
• 0.5 means to metric 50% of calls
• 0.1 means to metric 10% of calls

Usage

let broker = new ServiceBroker({
    metrics: true,
    metricsRate: 0.1
});

Context meta data (#16)

Added meta prop to Context. The meta will be merged if has parent context.
In case of remote calls the metadata will be transfered to the target service.

Usage

Set meta in broker.call:

// Broker call with meta data
broker.call("user.create", { name: "Adam", status: true}, {
    timeout: 1000,
    meta: {
        // Send logged in user data with request to the service
        loggedInUser: {
            userID: 45,
            roles: [ "admin" ]
        }
    }
})

Access meta in action:

broker.createService({
    name: "user",
    actions: {
        create(ctx) {
            const meta = ctx.meta;
            if (meta.loggedInUser && meta.loggedInUser.roles.indexOf("admin") !== -1)
                return Promise.resolve(...);
            else
                throw new CustomError("Access denied!");
        }
    }
});

Changes

Update benchmarkify

Benchmarkify updated & created continuous benchmarking with bench-bot.
Bench-bot is a benchmark runner. If a new Pull Request opened, bench-bot will run benchmarks against the master branch and it will post the results to the PR conversation.

Timeout & fallback response handling in local calls too

• Can be use timeout & fallback response in local calls.
• Timeout handling move from Transit to ServiceBroker
• Remove wrapContentAction
• In case of calling error, Node will be unavailable only if the error code >= 500

Context changes

• Removed createSubContext
• Removed ctx.parent and added ctx.parentID
• Removed options in constructor. New constructor syntax:

  let ctx = new Context(broker, action);
  ctx.setParams({ a: 5 });
  ctx.generateID(); // for metrics
  ctx.requestID = requestID;

• Add Context reference to returned Promise

  const p = broker.call("user.create");
  console.log("Context:", p.ctx);

Sender in event handlers

If an event triggered remotely on an other node, broker passes the nodeID of sender to the event handler as 2nd parameter.

// Usage in subscription
broker.on("**", (payload, sender) => console.log(`Event from ${sender || "local"}:`, payload));

// Usage in Service schema
broker.createService({
	...
	events: {
		something(payload, sender) {
			console.log(`Something happened on '${sender}':`, payload);			
		}
	}
});

Distributed timeout handling

Moleculer uses distributed timeouts.In the chained calls the ctx.call decrement the original timeout value with the elapsed time. If the new calculated timeout is less or equal than 0, it'll skip the next calls because the first call is rejected with RequestTimeoutError error.