Introduce more tools for use by plugins

node_modules/_app/clusterTools/getInstanceName.js

@@ -0,0 +1,40 @@
+const needle = require("needle");
+
+module.exports = function(config){
+	const instances = [];
+	
+	if(config){
+		return function getInstanceName(instanceID){
+			return new Promise((resolve, reject) => {
+				let instance = instances[instanceID];
+				if(!instance){
+					needle.get(config.masterIP+":"+config.masterPort+ '/api/slaves', (err, response) => {
+						if(err || response.statusCode != 200) {
+							console.log("Unable to get JSON master/api/slaves, master might be unaccessible");
+						} else if (response && response.body) {	
+							if(Buffer.isBuffer(response.body)) {console.log(response.body.toString("utf-8")); reject(new Error())}
+								try {
+									for (let index in response.body)
+										instances[index] = response.body[index].instanceName;
+								} catch (e){
+									console.log(e);
+									return null;
+								}
+							instance = instances[instanceID] 							
+							if (!instance) instance = instanceID;  //somehow the master doesn't know the instance	
+							resolve(instance);
+						}
+					});
+				} else {
+					resolve(instance);
+				}
+			});
+		}
+	} else {
+		return async function thisAintGonnaWork(){
+			let err = new Error("getInstanceName from _app/clusterTools needs to be called with {config} to work");
+			console.log(err);
+			throw err;
+		}
+	}
+}