added hierarchical structure to session

1 files changed, 168 insertions, 0 deletions

diff --git a/src/server/DashSessionAgent.ts b/src/server/DashSessionAgent.ts
new file mode 100644
index 000000000..3073e69c3
--- /dev/null
+++ b/src/server/DashSessionAgent.ts
@@ -0,0 +1,168 @@
+import { Email, pathFromRoot } from "./ActionUtilities";
+import { red, yellow, green, cyan } from "colors";
+import { get } from "request-promise";
+import { Utils } from "../Utils";
+import { WebSocket } from "./Websocket/Websocket";
+import { MessageStore } from "./Message";
+import { launchServer, onWindows } from ".";
+import { existsSync, mkdirSync, readdirSync, statSync, createWriteStream, readFileSync } from "fs";
+import * as Archiver from "archiver";
+import { resolve } from "path";
+import { AppliedSessionAgent, ExitHandler } from "./session/agents/applied_session_agent";
+import { Monitor } from "./session/agents/monitor";
+import { ServerWorker } from "./session/agents/server_worker";
+
+/**
+ * If we're the monitor (master) thread, we should launch the monitor logic for the session.
+ * Otherwise, we must be on a worker thread that was spawned *by* the monitor (master) thread, and thus
+ * our job should be to run the server.
+ */
+export class DashSessionAgent extends AppliedSessionAgent {
+
+    private readonly notificationRecipients = ["samuel_wilkins@brown.edu"];
+    private readonly signature = "-Dash Server Session Manager";
+    private readonly releaseDesktop = pathFromRoot("../../Desktop");
+    private _instructions: string | undefined;
+    private get instructions() {
+        if (!this._instructions) {
+            this._instructions = readFileSync(resolve(__dirname, "./remote_debug_instructions.txt"), { encoding: "utf8" });
+        }
+        return this._instructions;
+    }
+
+    protected async launchMonitor() {
+        const monitor = Monitor.Create(this.notifiers);
+        monitor.addReplCommand("pull", [], () => monitor.exec("git pull"));
+        monitor.addReplCommand("solr", [/start|stop|index/], this.executeSolrCommand);
+        monitor.addReplCommand("backup", [], this.backup);
+        monitor.addReplCommand("debug", [/active|passive/, /\S+\@\S+/], async ([mode, recipient]) => this.dispatchZippedDebugBackup(mode, recipient));
+        monitor.addServerMessageListener("backup", this.backup);
+        monitor.addServerMessageListener("debug", ({ args: { mode, recipient } }) => this.dispatchZippedDebugBackup(mode, recipient));
+        return monitor;
+    }
+
+    protected async launchServerWorker() {
+        const worker = ServerWorker.Create(launchServer); // server initialization delegated to worker
+        worker.addExitHandler(this.notifyClient);
+        return worker;
+    }
+
+    private readonly notifiers: Monitor.NotifierHooks = {
+        key: async key => {
+            // this sends a pseudorandomly generated guid to the configuration's recipients, allowing them alone
+            // to kill the server via the /kill/:key route
+            const content = `The key for this session (started @ ${new Date().toUTCString()}) is ${key}.\n\n${this.signature}`;
+            const failures = await Email.dispatchAll({
+                to: this.notificationRecipients,
+                subject: "Dash Release Session Admin Authentication Key",
+                content
+            });
+            if (failures) {
+                failures.map(({ recipient, error: { message } }) => this.sessionMonitor.mainLog(red(`dispatch failure @ ${recipient} (${yellow(message)})`)));
+                return false;
+            }
+            return true;
+        },
+        crash: async ({ name, message, stack }) => {
+            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${stack}`,
+                "The server is already restarting itself, but if you're concerned, use the Remote Desktop Connection to monitor progress.",
+            ].join("\n\n");
+            const content = `${body}\n\n${this.signature}`;
+            const failures = await Email.dispatchAll({
+                to: this.notificationRecipients,
+                subject: "Dash Web Server Crash",
+                content
+            });
+            if (failures) {
+                failures.map(({ recipient, error: { message } }) => this.sessionMonitor.mainLog(red(`dispatch failure @ ${recipient} (${yellow(message)})`)));
+                return false;
+            }
+            return true;
+        }
+    };
+
+    private executeSolrCommand = async (args: string[]) => {
+        const { exec, mainLog } = this.sessionMonitor;
+        const action = args[0];
+        if (action === "index") {
+            exec("npx ts-node ./updateSearch.ts", { cwd: pathFromRoot("./src/server") });
+        } else {
+            const command = `${onWindows ? "solr.cmd" : "solr"} ${args[0] === "start" ? "start" : "stop -p 8983"}`;
+            await exec(command, { cwd: "./solr-8.3.1/bin" });
+            try {
+                await get("http://localhost:8983");
+                mainLog(green("successfully connected to 8983 after running solr initialization"));
+            } catch {
+                mainLog(red("unable to connect at 8983 after running solr initialization"));
+            }
+        }
+    }
+
+    private notifyClient: ExitHandler = reason => {
+        const { _socket } = WebSocket;
+        if (_socket) {
+            const message = typeof reason === "boolean" ? (reason ? "exit" : "temporary") : "crash";
+            Utils.Emit(_socket, MessageStore.ConnectionTerminated, message);
+        }
+    }
+
+    private backup = async () => this.sessionMonitor.exec("backup.bat", { cwd: this.releaseDesktop });
+
+    private async dispatchZippedDebugBackup(mode: string, to: string) {
+        const { mainLog } = this.sessionMonitor;
+        try {
+            // if desired, complete an immediate backup to send
+            if (mode === "active") {
+                await this.backup();
+                mainLog("backup complete");
+            }
+
+            // ensure the directory for compressed backups exists
+            const backupsDirectory = `${this.releaseDesktop}/backups`;
+            const compressedDirectory = `${this.releaseDesktop}/compressed`;
+            if (!existsSync(compressedDirectory)) {
+                mkdirSync(compressedDirectory);
+            }
+
+            // sort all backups by their modified time, and choose the most recent one
+            const target = readdirSync(backupsDirectory).map(filename => ({
+                modifiedTime: statSync(`${backupsDirectory}/${filename}`).mtimeMs,
+                filename
+            })).sort((a, b) => b.modifiedTime - a.modifiedTime)[0].filename;
+            mainLog(`targeting ${target}...`);
+
+            // create a zip file and to it, write the contents of the backup directory
+            const zipName = `${target}.zip`;
+            const zipPath = `${compressedDirectory}/${zipName}`;
+            const output = createWriteStream(zipPath);
+            const zip = Archiver('zip');
+            zip.pipe(output);
+            zip.directory(`${backupsDirectory}/${target}/Dash`, false);
+            await zip.finalize();
+            mainLog(`zip finalized with size ${statSync(zipPath).size} bytes, saved to ${zipPath}`);
+
+            // dispatch the email to the recipient, containing the finalized zip file
+            const error = await Email.dispatch({
+                to,
+                subject: `Remote debug: compressed backup of ${target}...`,
+                content: this.instructions // prepare the body of the email with instructions on restoring the local database
+                    .replace(/__zipname__/, zipName)
+                    .replace(/__target__/, target)
+                    .replace(/__signature__/, this.signature),
+                attachments: [{ filename: zipName, path: zipPath }]
+            });
+
+            // indicate success or failure
+            mainLog(`${error === null ? green("successfully dispatched") : red("failed to dispatch")} ${zipName} to ${cyan(to)}`);
+            error && mainLog(red(error.message));
+        } catch (error) {
+            mainLog(red("unable to dispatch zipped backup..."));
+            mainLog(red(error.message));
+        }
+    }
+
+}
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