Merge branch 'master' of https://github.com/browngraphicslab/Dash-Web

1 files changed, 190 insertions, 0 deletions

diff --git a/src/server/ChildProcessUtilities/daemon/session.ts b/src/server/ChildProcessUtilities/daemon/session.ts
new file mode 100644
index 000000000..fb2b3551e
--- /dev/null
+++ b/src/server/ChildProcessUtilities/daemon/session.ts
@@ -0,0 +1,190 @@
+import * as request from "request-promise";
+import { log_execution, pathFromRoot } from "../../ActionUtilities";
+import { red, yellow, cyan, green, Color } from "colors";
+import * as nodemailer from "nodemailer";
+import { MailOptions } from "nodemailer/lib/json-transport";
+import { writeFileSync, existsSync, mkdirSync } from "fs";
+import { resolve } from 'path';
+import { ChildProcess, exec, execSync } from "child_process";
+import { createInterface } from "readline";
+const killport = require("kill-port");
+
+process.on('SIGINT', endPrevious);
+const identifier = yellow("__session_manager__:");
+
+let manualRestartActive = false;
+createInterface(process.stdin, process.stdout).on('line', async line => {
+    const prompt = line.trim().toLowerCase();
+    switch (prompt) {
+        case "restart":
+            manualRestartActive = true;
+            identifiedLog(cyan("Initializing manual restart..."));
+            await endPrevious();
+            break;
+        case "exit":
+            identifiedLog(cyan("Initializing session end"));
+            await endPrevious();
+            identifiedLog("Cleanup complete. Exiting session...\n");
+            execSync(killAllCommand());
+            break;
+        default:
+            identifiedLog(red("commands: { exit, restart }"));
+            return;
+    }
+});
+
+const logPath = resolve(__dirname, "./logs");
+const crashPath = resolve(logPath, "./crashes");
+if (!existsSync(logPath)) {
+    mkdirSync(logPath);
+}
+if (!existsSync(crashPath)) {
+    mkdirSync(crashPath);
+}
+
+const crashLogPath = resolve(crashPath, `./session_crashes_${new Date().toISOString()}.log`);
+function addLogEntry(message: string, color: Color) {
+    const formatted = color(`${message} ${timestamp()}.`);
+    identifiedLog(formatted);
+    // appendFileSync(crashLogPath, `${formatted}\n`);
+}
+
+function identifiedLog(message?: any, ...optionalParams: any[]) {
+    console.log(identifier, message, ...optionalParams);
+}
+
+if (!["win32", "darwin"].includes(process.platform)) {
+    identifiedLog(red("Invalid operating system: this script is supported only on Mac and Windows."));
+    process.exit(1);
+}
+
+const latency = 10;
+const ports = [1050, 4321];
+const onWindows = process.platform === "win32";
+const LOCATION = "http://localhost";
+const heartbeat = `${LOCATION}:1050/serverHeartbeat`;
+const recipient = "samuel_wilkins@brown.edu";
+const { pid } = process;
+let restarting = false;
+let count = 0;
+
+function startServerCommand() {
+    if (onWindows) {
+        return '"C:\\Program Files\\Git\\git-bash.exe" -c "npm run start-release"';
+    }
+    return `osascript -e 'tell app "Terminal"\ndo script "cd ${pathFromRoot()} && npm run start-release"\nend tell'`;
+}
+
+function killAllCommand() {
+    if (onWindows) {
+        return "taskkill /f /im node.exe";
+    }
+    return "killall -9 node";
+}
+
+identifiedLog("Initializing session...");
+
+writeLocalPidLog("session_manager", pid);
+
+function writeLocalPidLog(filename: string, contents: any) {
+    const path = `./logs/current_${filename}_pid.log`;
+    identifiedLog(cyan(`${contents} written to ${path}`));
+    writeFileSync(resolve(__dirname, path), `${contents}\n`);
+}
+
+function timestamp() {
+    return `@ ${new Date().toISOString()}`;
+}
+
+async function endPrevious() {
+    identifiedLog(yellow("Cleaning up previous connections..."));
+    current_backup?.kill("SIGTERM");
+    await Promise.all(ports.map(port => {
+        const task = killport(port, 'tcp');
+        return task.catch((error: any) => identifiedLog(red(error)));
+    }));
+    identifiedLog(yellow("Done. Any failures will be printed in red immediately above."));
+}
+
+let current_backup: ChildProcess | undefined = undefined;
+
+async function checkHeartbeat() {
+    let error: any;
+    try {
+        count && !restarting && process.stdout.write(`${identifier} 👂 `);
+        await request.get(heartbeat);
+        count && !restarting && console.log('⇠ 💚');
+        if (restarting || manualRestartActive) {
+            addLogEntry(count++ ? "Backup server successfully restarted" : "Server successfully started", green);
+            restarting = false;
+        }
+    } catch (e) {
+        count && !restarting && console.log("⇠ 💔");
+        error = e;
+    } finally {
+        if (error) {
+            if (!restarting || manualRestartActive) {
+                restarting = true;
+                if (count && !manualRestartActive) {
+                    console.log();
+                    addLogEntry("Detected a server crash", red);
+                    identifiedLog(red(error.message));
+                    await endPrevious();
+                    await log_execution({
+                        startMessage: identifier + " Sending crash notification email",
+                        endMessage: ({ error, result }) => {
+                            const success = error === null && result === true;
+                            return identifier + ` ${(success ? `Notification successfully sent to` : `Failed to notify`)} ${recipient} ${timestamp()}`;
+                        },
+                        action: async () => notify(error || "Hmm, no error to report..."),
+                        color: cyan
+                    });
+                    identifiedLog(green("Initiating server restart..."));
+                }
+                manualRestartActive = false;
+                current_backup = exec(startServerCommand(), err => identifiedLog(err?.message || count ? "Previous server process exited." : "Spawned initial server."));
+                writeLocalPidLog("server", `${(current_backup?.pid ?? -2) + 1} created ${timestamp()}`);
+            }
+        }
+        setTimeout(checkHeartbeat, 1000 * latency);
+    }
+}
+
+async function startListening() {
+    identifiedLog(yellow(`After initialization, will poll server heartbeat repeatedly...\n`));
+    if (!LOCATION) {
+        identifiedLog(red("No location specified for session manager. Please include as a command line environment variable or in a .env file."));
+        process.exit(0);
+    }
+    await checkHeartbeat();
+}
+
+function emailText(error: any) {
+    return [
+        `Hey ${recipient.split("@")[0]},`,
+        "You, as a Dash Administrator, are being notified of a server crash event. Here's what we know:",
+        `Location: ${LOCATION}\nError: ${error}`,
+        "The server should already be restarting itself, but if you're concerned, use the Remote Desktop Connection to monitor progress."
+    ].join("\n\n");
+}
+
+async function notify(error: any) {
+    const smtpTransport = nodemailer.createTransport({
+        service: 'Gmail',
+        auth: {
+            user: 'brownptcdash@gmail.com',
+            pass: 'browngfx1'
+        }
+    });
+    const mailOptions = {
+        to: recipient,
+        from: 'brownptcdash@gmail.com',
+        subject: 'Dash Server Crash',
+        text: emailText(error)
+    } as MailOptions;
+    return new Promise<boolean>(resolve => {
+        smtpTransport.sendMail(mailOptions, (dispatchError: Error | null) => resolve(dispatchError === null));
+    });
+}
+
+startListening();
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