A JavaScript Mobile Agent Platform that allows an agent to migrate across a network. A Supervisor node dispatches the Agent which can then autonomously move between Worker nodes, carrying/transferring its state and methods to the new node.
Install:
npm i mobile-agent-platform
The following example shows how to declare an Agent that will traverse across 5 nodes.
Upon executing on each node it will display a "Running" message, before moving to the next node after 2 seconds.
const {Supervisor, Agent} = require('mobile-agent-platform');
const port = 3000
//Create a new supervisor that listens on http://192.168.100.0:3000
const supervisor = Supervisor("192.168.100.0", port);
// Creates a new agent that prints a message every second using state.output
let agent = Agent({
supervisor,
// A friendly name for the Agent
name: "Example Agent",
// The path that the agent will follow
nodePath: [
'http://192.168.100.1:4000/agent',
'http://192.168.100.2:4000/agent',
'http://192.168.100.3:4000/agent',
'http://192.168.100.4:4000/agent',
'http://192.168.100.5:4000/agent'
],
// The main method that gets called when the Agent is initialized
main: (state, args) => {
//Output to the Supervisor node console
state.output(`Running ${state.name} on node ${state.nodePath[state.currentNode]} with id ${state.currentNode}`);
//Move to the next node after 2 seconds
state.setTimeout(() => state.move(), 2000);
}
});
//Start the agent, moves to the first node.
agent.dispatch();const { Worker } = require('mobile-agent-platform');
//Create a new Worker node that listens on port 4000 by default.
//Can be changed using Worker(portNum)
//Will accept Agents trying to move to this Worker and will handle reinitializing the Agent.
let worker = Worker();Supervisor listening at http://192.168.100.0:3000
Worker0 - 18:49:25 | Stopping Example Agent on node http://192.168.100.1:4000/agent with id 0
Worker0 - 18:49:26 | Running Example Agent on node http://192.168.100.1:4000/agent with id 0
Worker1 - 18:49:27 | Stopping Example Agent on node http://192.168.100.2:4000/agent with id 1
Worker1 - 18:49:28 | Running Example Agent on node http://192.168.100.2:4000/agent with id 1
Worker2 - 18:49:29 | Stopping Example Agent on node http://192.168.100.3:4000/agent with id 2
Worker2 - 18:49:30 | Running Example Agent on node http://192.168.100.3:4000/agent with id 2
Worker3 - 18:49:31 | Stopping Example Agent on node http://192.168.100.4:4000/agent with id 3
Worker3 - 18:49:32 | Running Example Agent on node http://192.168.100.4:4000/agent with id 3
Worker4 - 18:49:33 | Stopping Example Agent on node http://192.168.100.5:4000/agent with id 4
Worker4 - 18:49:34 | Running Example Agent on node http://192.168.100.5:4000/agent with id 4
Worker0 - 18:49:35 | Stopping Example Agent on node http://192.168.100.1:4000/agent with id 0
Worker0 - 18:49:36 | Running Example Agent on node http://192.168.100.1:4000/agent with id 0
Worker1 - 18:49:37 | Stopping Example Agent on node http://192.168.100.2:4000/agent with id 1
Worker1 - 18:49:38 | Running Example Agent on node http://192.168.100.2:4000/agent with id 1
Worker2 - 18:49:39 | Stopping Example Agent on node http://192.168.100.3:4000/agent with id 2
Worker2 - 18:49:40 | Running Example Agent on node http://192.168.100.3:4000/agent with id 2
......
Path is cyclic in nature by default
The package makes use of JSON Web Tokens to verify that an Agent being received at a Worker node has not been tampered with, and is coming from a verified source.
For this to work, every node (including both Supervisor and Worker nodes) must have a shared TOKEN_SECRET environment variable.
Within the main directory of your project you must have a .env file containing the following.
.env file:
# We recommend choosing a strong secret for example:
TOKEN_SECRET:OFhvMqCBvh9XrkAbOKEjUmy3PW02jA9gOB8u3hAo0VVSsvQ0oNioeiiEiuJSyZWPRoI6ETa824p9HWr7W6T8XCL60jr9z2cSYH8YfJflaP15ea0YiKiHlSHmgD91L9Y0
state.declareStore({key: value, key: value, key: value}) can be used to declare a new variable that will persist across nodes.
state.store.key can be used to access and/or mutate these values once declared.
let agent = Agent({
supervisor,
name: "Example Agent",
// The path that the agent will follow
nodePath: ['http://localhost:4000/agent', 'http://localhost:4001/agent', 'http://localhost:4002/agent', 'http://localhost:4003/agent', 'http://localhost:4004/agent'],
main: (state, args) => {
//Declare as many variables as you like
//Will declare if the key is undefined, otherwise it will not mutate the value.
state.declareStore({counter: 0, anotherVariable: "Another Value"});
//Increment counter and output every second
state.setInterval(() => {
state.store.counter++;
//Output to the Supervisor node console
state.output(`Counter: ${state.store.counter}`);
}, 1000)
//Move to the next node after 2 seconds
state.setTimeout(() => state.move(), 2000);
}
});Supervisor listening at http://localhost:3000
Supervisor - 20:12:31 | Dispatching Example Agent from supervisor node http://localhost:3000
Worker 0 - 20:12:32 | Counter: 1
Worker 0 - 20:12:33 | Stopping Example Agent on node http://localhost:4000/agent
Worker 1 - 20:12:34 | Counter: 2
Worker 1 - 20:12:35 | Stopping Example Agent on node http://localhost:4001/agent
Worker 2 - 20:12:36 | Counter: 3
Worker 2 - 20:12:37 | Stopping Example Agent on node http://localhost:4002/agent
Custom methods can be added by adding your method to the methods attribute like so.
That method can then be called by using state.methods.NAME.
let agent = Agent({
supervisor,
name: "Old Name",
nodePath: ['http://localhost:4000/agent', 'http://localhost:4001/agent', 'http://localhost:4002/agent', 'http://localhost:4003/agent', 'http://localhost:4004/agent'],
main: (state, args) => {
// Change the name to "New Name" when the agent has reached the 3rd node.
if (state.currentNode === 2)
state.methods.changeName(state, "New Name");
// Print the Agent's current name.
state.output(`The Agent's current name is ${state.name}`)
//Move to the next node after 2 seconds
state.setTimeout(() => state.move(), 2000);
},
methods: {
changeName: function(state, newName) {
state.name = newName;
}
}
});Supervisor - 18:40:43 | Dispatching Old Name from supervisor node http://localhost:3000
Worker 0 - 18:40:43 | The Agent's current name is Old Name
Worker 0 - 18:40:45 | Stopping Old Name on node http://localhost:4000/agent
Worker 1 - 18:40:45 | The Agent's current name is Old Name
Worker 1 - 18:40:47 | Stopping Old Name on node http://localhost:4001/agent
Worker 2 - 18:40:47 | The Agent's current name is New Name
Worker 2 - 18:40:49 | Stopping New Name on node http://localhost:4002/agent
Worker 3 - 18:40:49 | The Agent's current name is New Name
Worker 3 - 18:40:51 | Stopping New Name on node http://localhost:4003/agent
Worker 4 - 18:40:51 | The Agent's current name is New Name
Worker 4 - 18:40:53 | Stopping New Name on node http://localhost:4004/agent
If you wish to override some of the already implemented methods such as init or stop you can do so by passing these as attributes to the constructor.
let agent = Agent({
supervisor,
name: "Example Agent",
nodePath: ['http://localhost:4000/agent', 'http://localhost:4001/agent', 'http://localhost:4002/agent', 'http://localhost:4003/agent', 'http://localhost:4004/agent'],
main: (state, args) => {
state.output("Ran main!");
//Move to the next node after 2 seconds
state.setTimeout(() => state.move(), 2000);
},
init: function(state, args) {
state.output("Custom init....");
state.main();
}
});Supervisor - 19:31:55 | Dispatching Example Agent from supervisor node http://localhost:3000
Worker 0 - 19:31:55 | Ran main!
Worker 0 - 19:31:55 | Custom init....
Worker 0 - 19:31:57 | Stopping Example Agent on node http://localhost:4000/agent
Worker 1 - 19:31:57 | Custom init....
Worker 1 - 19:31:57 | Ran main!
Worker 1 - 19:31:59 | Stopping Example Agent on node http://localhost:4001/agent
Worker 2 - 19:31:59 | Custom init....
Worker 2 - 19:31:59 | Ran main!
Worker 2 - 19:32:01 | Stopping Example Agent on node http://localhost:4002/agent
.....
Continues