port config, customizers

4 files changed, 141 insertions, 72 deletions

diff --git a/src/server/Session/session.ts b/src/server/Session/session.ts
index 789a40c42..61b8bcf16 100644
--- a/src/server/Session/session.ts
+++ b/src/server/Session/session.ts
@@ -1,12 +1,10 @@
 import { red, cyan, green, yellow, magenta } from "colors";
-import { isMaster, on, fork, setupMaster, Worker } from "cluster";
+import { on, fork, setupMaster, Worker } from "cluster";
 import { execSync } from "child_process";
 import { get } from "request-promise";
-import { WebSocket } from "../Websocket/Websocket";
 import { Utils } from "../../Utils";
-import { MessageStore } from "../Message";
 import { Email } from "../ActionUtilities";
-import Repl from "../repl";
+import Repl, { ReplAction } from "../repl";
 import { readFileSync } from "fs";
 import { validate, ValidationError } from "jsonschema";
 import { configurationSchema } from "./session_config_schema";
@@ -26,26 +24,35 @@ const onWindows = process.platform === "win32";
      */
 export namespace Session {
 
+    interface MasterCustomizer {
+        addReplCommand: (basename: string, argPatterns: (RegExp | string)[], action: ReplAction) => void;
+        addChildMessageHandler: (message: string, handler: ActionHandler) => void;
+    }
+
+    export interface SessionAction {
+        message: string;
+        args: any;
+    }
+
+    export type ExitHandler = (error: Error) => void | Promise<void>;
+    export type ActionHandler = (action: SessionAction) => void | Promise<void>;
+    export interface EmailTemplate {
+        subject: string;
+        body: string;
+    }
+    export type CrashEmailGenerator = (error: Error) => EmailTemplate | Promise<EmailTemplate>;
+
     /**
      * Validates and reads the configuration file, accordingly builds a child process factory
      * and spawns off an initial process that will respawn as predecessors die.
      */
-    export async function initializeMonitorThread(): Promise<Repl> {
+    export async function initializeMonitorThread(crashEmailGenerator?: CrashEmailGenerator): Promise<MasterCustomizer> {
         let activeWorker: Worker;
+        const childMessageHandlers: { [message: string]: (action: SessionAction, args: any) => void } = {};
 
         // read in configuration .json file only once, in the master thread
         // pass down any variables the pertinent to the child processes as environment variables
-        const {
-            masterIdentifier,
-            workerIdentifier,
-            recipients,
-            signature,
-            heartbeatRoute,
-            serverPort,
-            socketPort,
-            showServerOutput,
-            pollingIntervalSeconds
-        } = function loadConfiguration(): any {
+        const configuration = function loadConfiguration(): any {
             try {
                 const configuration = JSON.parse(readFileSync('./session.config.json', 'utf8'));
                 const options = {
@@ -54,8 +61,8 @@ export namespace Session {
                 };
                 // ensure all necessary and no excess information is specified by the configuration file
                 validate(configuration, configurationSchema, options);
-                configuration.masterIdentifier = `${yellow(configuration.masterIdentifier)}:`;
-                configuration.workerIdentifier = `${magenta(configuration.workerIdentifier)}:`;
+                configuration.masterIdentifier = yellow(configuration.masterIdentifier + ":");
+                configuration.workerIdentifier = magenta(configuration.workerIdentifier + ":");
                 return configuration;
             } catch (error) {
                 console.log(red("\nSession configuration failed."));
@@ -73,6 +80,17 @@ export namespace Session {
             }
         }();
 
+        const {
+            masterIdentifier,
+            workerIdentifier,
+            recipients,
+            ports,
+            signature,
+            heartbeatRoute,
+            showServerOutput,
+            pollingIntervalSeconds
+        } = configuration;
+
         // this sends a pseudorandomly generated guid to the configuration's recipients, allowing them alone
         // to kill the server via the /kill/:key route
         const key = Utils.GenerateGuid();
@@ -92,7 +110,7 @@ export namespace Session {
             if (message !== "Channel closed") {
                 console.log(masterIdentifier, red(message));
                 if (stack) {
-                    console.log(masterIdentifier, `\n${red(stack)}`);
+                    console.log(masterIdentifier, `uncaught exception\n${red(stack)}`);
                 }
             }
         });
@@ -113,39 +131,56 @@ export namespace Session {
             return false;
         };
 
+        const restart = () => {
+            // indicate to the worker that we are 'expecting' this restart
+            activeWorker.send({ setListening: false });
+            tryKillActiveWorker();
+        };
+
+        const setPort = (port: string, value: number, immediateRestart: boolean) => {
+            ports[port] = value;
+            if (immediateRestart) {
+                restart();
+            }
+        };
+
         // kills the current active worker and proceeds to spawn a new worker,
         // feeding in configuration information as environment variables
         const spawn = (): void => {
             tryKillActiveWorker();
             activeWorker = fork({
                 heartbeatRoute,
-                serverPort,
-                socketPort,
+                serverPort: ports.server,
+                socketPort: ports.socket,
                 pollingIntervalSeconds,
                 session_key: key
             });
             console.log(masterIdentifier, `spawned new server worker with process id ${activeWorker.process.pid}`);
             // an IPC message handler that executes actions on the master thread when prompted by the active worker
-            activeWorker.on("message", ({ lifecycle, action }) => {
+            activeWorker.on("message", async ({ lifecycle, action }) => {
                 if (action) {
-                    const { message, args } = action;
+                    const { message, args } = action as SessionAction;
                     console.log(`${workerIdentifier} action requested (${cyan(message)})`);
                     switch (message) {
                         case "kill":
-                            console.log(masterIdentifier, red("An authorized user has ended the server session from the /kill route"));
+                            console.log(masterIdentifier, red("An authorized user has manually ended the server session"));
                             tryKillActiveWorker(false);
                             process.exit(0);
                         case "notify_crash":
-                            const { error: { name, message, stack } } = args;
-                            const content = [
-                                "You, as a Dash Administrator, are being notified of a server crash event. Here's what we know:",
-                                `name:\n${name}`,
-                                `message:\n${message}`,
-                                `stack:\n${stack}`,
-                                "The server is already restarting itself, but if you're concerned, use the Remote Desktop Connection to monitor progress.",
-                                signature
-                            ].join("\n\n");
-                            Email.dispatchAll(recipients, "Dash Web Server Crash", content);
+                            if (crashEmailGenerator) {
+                                const { error } = args;
+                                const { subject, body } = await crashEmailGenerator(error);
+                                const content = `${body}\n\n${signature}`;
+                                Email.dispatchAll(recipients, subject, content);
+                            }
+                        case "set_port":
+                            const { port, value, immediateRestart } = args;
+                            setPort(port, value, immediateRestart);
+                        default:
+                            const handler = childMessageHandlers[message];
+                            if (handler) {
+                                handler(action, args);
+                            }
                     }
                 } else if (lifecycle) {
                     console.log(`${workerIdentifier} lifecycle phase (${lifecycle})`);
@@ -155,7 +190,7 @@ export namespace Session {
 
         // a helpful cluster event called on the master thread each time a child process exits
         on("exit", ({ process: { pid } }, code, signal) => {
-            const prompt = `Server worker with process id ${pid} has exited with code ${code}${signal === null ? "" : `, having encountered signal ${signal}`}.`;
+            const prompt = `server worker with process id ${pid} has exited with code ${code}${signal === null ? "" : `, having encountered signal ${signal}`}.`;
             console.log(masterIdentifier, cyan(prompt));
             // to make this a robust, continuous session, every time a child process dies, we immediately spawn a new one
             spawn();
@@ -164,17 +199,18 @@ export namespace Session {
         // builds the repl that allows the following commands to be typed into stdin of the master thread
         const repl = new Repl({ identifier: masterIdentifier });
         repl.registerCommand("exit", [], () => execSync(onWindows ? "taskkill /f /im node.exe" : "killall -9 node"));
-        repl.registerCommand("restart", [], () => {
-            // indicate to the worker that we are 'expecting' this restart
-            activeWorker.send({ setListening: false });
-            tryKillActiveWorker();
+        repl.registerCommand("restart", [], restart);
+        repl.registerCommand("set", [/[a-zA-Z]+/g, "port", /\d+/g, /true|false/g], args => {
+            setPort(args[0], Number(args[2]), args[3] === "true");
         });
-
         // finally, set things in motion by spawning off the first child (server) process
         spawn();
 
         // returned to allow the caller to add custom commands
-        return repl;
+        return {
+            addReplCommand: repl.registerCommand,
+            addChildMessageHandler: (message: string, handler: ActionHandler) => { childMessageHandlers[message] = handler; }
+        };
     }
 
     /**
@@ -183,8 +219,9 @@ export namespace Session {
      * email if the server encounters an uncaught exception or if the server cannot be reached.
      * @param work the function specifying the work to be done by each worker thread
      */
-    export async function initializeWorkerThread(work: Function): Promise<void> {
+    export async function initializeWorkerThread(work: Function): Promise<(handler: ExitHandler) => void> {
         let listening = false;
+        const exitHandlers: ExitHandler[] = [];
 
         // notify master thread (which will log update in the console) of initialization via IPC
         process.send?.({ lifecycle: green("initializing...") });
@@ -194,7 +231,7 @@ export namespace Session {
 
         // called whenever the process has a reason to terminate, either through an uncaught exception
         // in the process (potentially inconsistent state) or the server cannot be reached
-        const activeExit = (error: Error): void => {
+        const activeExit = async (error: Error): Promise<void> => {
             if (!listening) {
                 return;
             }
@@ -206,11 +243,7 @@ export namespace Session {
                     args: { error }
                 }
             });
-            const { _socket } = WebSocket;
-            // notifies all client users of a crash event
-            if (_socket) {
-                Utils.Emit(_socket, MessageStore.ConnectionTerminated, "Manual");
-            }
+            await Promise.all(exitHandlers.map(handler => handler(error)));
             // notify master thread (which will log update in the console) of crash event via IPC
             process.send?.({ lifecycle: red(`Crash event detected @ ${new Date().toUTCString()}`) });
             process.send?.({ lifecycle: red(error.message) });
@@ -253,6 +286,8 @@ export namespace Session {
 
         work();
         checkHeartbeat(); // begin polling
+
+        return (handler: ExitHandler) => exitHandlers.push(handler);
     }
 
 }
\ No newline at end of file
diff --git a/src/server/Session/session_config_schema.ts b/src/server/Session/session_config_schema.ts
index 03009a351..34d1ad523 100644
--- a/src/server/Session/session_config_schema.ts
+++ b/src/server/Session/session_config_schema.ts
@@ -3,7 +3,7 @@ import { Schema } from "jsonschema";
 const emailPattern = /^(([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+)?$/g;
 const localPortPattern = /\/[a-zA-Z]+/g;
 
-const properties = {
+const properties: { [name: string]: Schema } = {
     recipients: {
         type: "array",
         items: {
@@ -12,8 +12,15 @@ const properties = {
         },
         minLength: 1
     },
-    serverPort: { type: "number" },
-    socketPort: { type: "number" },
+    ports: {
+        type: "object",
+        properties: {
+            server: { type: "number" },
+            socket: { type: "number" }
+        },
+        required: ["server"],
+        additionalProperties: true
+    },
     heartbeatRoute: {
         type: "string",
         pattern: localPortPattern
diff --git a/src/server/index.ts b/src/server/index.ts
index 4400687d8..0fee41bd8 100644
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -26,6 +26,8 @@ import { yellow } from "colors";
 import { Session } from "./Session/session";
 import { isMaster } from "cluster";
 import { execSync } from "child_process";
+import { Utils } from "../Utils";
+import { MessageStore } from "./Message";
 
 export const publicDirectory = path.resolve(__dirname, "public");
 export const filesDirectory = path.resolve(publicDirectory, "files");
@@ -132,17 +134,31 @@ function routeSetter({ isRelease, addSupervisedRoute, logRegistrationOutcome }:
 /**
  * Thread dependent session initialization
  */
-if (isMaster) {
-    Session.initializeMonitorThread().then(({ registerCommand }) => {
-        registerCommand("pull", [], () => execSync("git pull", { stdio: ["ignore", "inherit", "inherit"] }));
-    });
-} else {
-    Session.initializeWorkerThread(async () => {
-        await log_execution({
-            startMessage: "\nstarting execution of preliminary functions",
-            endMessage: "completed preliminary functions\n",
-            action: preliminaryFunctions
+(async function launch() {
+    if (isMaster) {
+        const emailGenerator = (error: Error) => {
+            const subject = "Dash Web Server Crash";
+            const { name, message, stack } = error;
+            const body = [
+                "You, as a Dash Administrator, are being notified of a server crash event. Here's what we know:",
+                `name:\n${name}`,
+                `message:\n${message}`,
+                `stack:\n${stack}`,
+                "The server is already restarting itself, but if you're concerned, use the Remote Desktop Connection to monitor progress.",
+            ].join("\n\n");
+            return { subject, body };
+        };
+        const customizer = await Session.initializeMonitorThread(emailGenerator);
+        customizer.addReplCommand("pull", [], () => execSync("git pull", { stdio: ["ignore", "inherit", "inherit"] }));
+    } else {
+        const addExitHandler = await Session.initializeWorkerThread(async () => {
+            await log_execution({
+                startMessage: "\nstarting execution of preliminary functions",
+                endMessage: "completed preliminary functions\n",
+                action: preliminaryFunctions
+            });
+            await initializeServer(routeSetter);
         });
-        await initializeServer(routeSetter);
-    });
-}
\ No newline at end of file
+        addExitHandler(() => Utils.Emit(WebSocket._socket, MessageStore.ConnectionTerminated, "Manual"));
+    }
+})();
\ No newline at end of file
diff --git a/src/server/repl.ts b/src/server/repl.ts
index ec525582b..a47d4aad4 100644
--- a/src/server/repl.ts
+++ b/src/server/repl.ts
@@ -1,30 +1,33 @@
 import { createInterface, Interface } from "readline";
-import { red } from "colors";
+import { red, green, white } from "colors";
 
 export interface Configuration {
     identifier: string;
     onInvalid?: (culprit?: string) => string | string;
+    onValid?: (success?: string) => string | string;
     isCaseSensitive?: boolean;
 }
 
-type Action = (parsedArgs: IterableIterator<string>) => any | Promise<any>;
+export type ReplAction = (parsedArgs: Array<string>) => any | Promise<any>;
 export interface Registration {
     argPatterns: RegExp[];
-    action: Action;
+    action: ReplAction;
 }
 
 export default class Repl {
     private identifier: string;
-    private onInvalid: ((culprit?: string) => string) | string;
+    private onInvalid: (culprit?: string) => string | string;
+    private onValid: (success: string) => string | string;
     private isCaseSensitive: boolean;
     private commandMap = new Map<string, Registration[]>();
     public interface: Interface;
     private busy = false;
     private keys: string | undefined;
 
-    constructor({ identifier: prompt, onInvalid, isCaseSensitive }: Configuration) {
+    constructor({ identifier: prompt, onInvalid, onValid, isCaseSensitive }: Configuration) {
         this.identifier = prompt;
         this.onInvalid = onInvalid || this.usage;
+        this.onValid = onValid || this.success;
         this.isCaseSensitive = isCaseSensitive ?? true;
         this.interface = createInterface(process.stdin, process.stdout).on('line', this.considerInput);
     }
@@ -43,7 +46,9 @@ export default class Repl {
         return `${this.identifier} commands: { ${members.sort().join(", ")} }`;
     }
 
-    public registerCommand = (basename: string, argPatterns: (RegExp | string)[], action: Action) => {
+    private success = (command: string) => `${this.identifier} completed execution of ${white(command)}`;
+
+    public registerCommand = (basename: string, argPatterns: (RegExp | string)[], action: ReplAction) => {
         const existing = this.commandMap.get(basename);
         const converted = argPatterns.map(input => input instanceof RegExp ? input : new RegExp(input));
         const registration = { argPatterns: converted, action };
@@ -59,7 +64,13 @@ export default class Repl {
         this.busy = false;
     }
 
+    private valid = (command: string) => {
+        console.log(green(typeof this.onValid === "string" ? this.onValid : this.onValid(command)));
+        this.busy = false;
+    }
+
     private considerInput = async (line: string) => {
+        console.log("raw", line);
         if (this.busy) {
             console.log(red("Busy"));
             return;
@@ -91,8 +102,8 @@ export default class Repl {
                     matched = true;
                 }
                 if (!length || matched) {
-                    await action(parsed[Symbol.iterator]());
-                    this.busy = false;
+                    await action(parsed);
+                    this.valid(`${command} ${parsed.join(" ")}`);
                     return;
                 }
             }