cli, core: support invoking remote commands (#1185)

* cli, core: support launching remote commands

* fixes

* preserve buffer format for child process

packages/cli/src/main.ts

@@ -236,7 +236,9 @@ async function main() {
             }
         });
 
-        await connectShell(sdk);
+        const separator = process.argv.indexOf("--");
+        const cmd = separator != -1 ? process.argv.slice(separator + 1): [];
+        await connectShell(sdk, ...cmd);
     }
     else {
         console.log('usage:');
@@ -249,7 +251,7 @@ async function main() {
         console.log('   npx scrypted command name-or-id[@127.0.0.1[:10443]] method-name [...method-arguments]');
         console.log('   npx scrypted ffplay name-or-id[@127.0.0.1[:10443]] method-name [...method-arguments]');
         console.log('   npx scrypted create-cert-json /path/to/key.pem /path/to/cert.pem');
-        console.log('   npx scrypted shell [127.0.0.1[:10443]]');
+        console.log('   npx scrypted shell [127.0.0.1[:10443]] [-- cmd [...cmd-args]]');
         console.log();
         console.log('examples:');
         console.log('   npx scrypted install @scrypted/rtsp');

packages/cli/src/shell.ts

@@ -1,7 +1,7 @@
 import { DeviceProvider, ScryptedStatic, StreamService } from "@scrypted/types";
 import { createAsyncQueue } from '../../../common/src/async-queue';
 
-export async function connectShell(sdk: ScryptedStatic) {
+export async function connectShell(sdk: ScryptedStatic, ...cmd: string[]) {
     const termSvc = await sdk.systemManager.getDeviceByName<DeviceProvider>("@scrypted/core").getDevice("terminalservice");
     if (!termSvc) {
         throw Error("@scrypted/core does not provide a Terminal Service");
@@ -19,7 +19,7 @@ export async function connectShell(sdk: ScryptedStatic) {
             dataQueue.enqueue(Buffer.alloc(0));
         });
     }
-    ctrlQueue.enqueue({ interactive: Boolean(process.stdin.isTTY) });
+    ctrlQueue.enqueue({ interactive: Boolean(process.stdin.isTTY), cmd: cmd });
 
     const dim = { cols: process.stdout.columns, rows: process.stdout.rows };
     ctrlQueue.enqueue({ dim });

plugins/core/src/terminal-service.ts

@@ -9,9 +9,13 @@ export const TerminalServiceNativeId = 'terminalservice';
 class InteractiveTerminal {
     cp: IPty
 
-    constructor() {
+    constructor(cmd: string[]) {
         const spawn = require('node-pty-prebuilt-multiarch').spawn as typeof ptySpawn;
-        this.cp = spawn(process.env.SHELL as string, [], {});
+        if (cmd?.length) {
+            this.cp = spawn(cmd[0], cmd.slice(1), {});
+        } else {
+            this.cp = spawn(process.env.SHELL as string, [], {});
+        }
     }
 
     onExit(fn: (e: { exitCode: number; signal?: number; }) => any) {
@@ -30,8 +34,8 @@ class InteractiveTerminal {
         this.cp.resume();
     }
 
-    write(data: string) {
-        this.cp.write(data);
+    write(data: Buffer) {
+        this.cp.write(data.toString());
     }
 
     sendEOF() {
@@ -43,15 +47,20 @@ class InteractiveTerminal {
     }
 
     resize(columns: number, rows: number) {
-        this.cp.resize(columns, rows);
+        if (columns > 0 && rows > 0)
+            this.cp.resize(columns, rows);
     }
 }
 
 class NoninteractiveTerminal {
     cp: ChildProcess
 
-    constructor() {
-        this.cp = childSpawn(process.env.SHELL as string);
+    constructor(cmd: string[]) {
+        if (cmd?.length) {
+            this.cp = childSpawn(cmd[0], cmd.slice(1));
+        } else {
+            this.cp = childSpawn(process.env.SHELL as string);
+        }
     }
 
     onExit(fn: (code: number, signal: NodeJS.Signals) => void) {
@@ -69,11 +78,11 @@ class NoninteractiveTerminal {
     }
 
     resume() {
-        this.cp.stdout.pause();
-        this.cp.stderr.pause();
+        this.cp.stdout.resume();
+        this.cp.stderr.resume();
     }
 
-    write(data: any) {
+    write(data: Buffer) {
         this.cp.stdin.write(data);
     }
 
@@ -92,7 +101,17 @@ class NoninteractiveTerminal {
 
 
 export class TerminalService extends ScryptedDeviceBase implements StreamService {
-    async connectStream(input: AsyncGenerator<any, void>): Promise<AsyncGenerator<any, void>> {
+    /*
+     * The input to this stream can send buffers for normal terminal data and strings
+     * for control messages. Control messages are JSON-formatted.
+     *
+     * The current implemented control messages:
+     *
+     *   Start: { "interactive": boolean, "cmd": string[] }
+     *   Resize: { "dim": { "cols": number, "rows": number } }
+     *   EOF: { "eof": true }
+     */
+    async connectStream(input: AsyncGenerator<Buffer | string, void>): Promise<AsyncGenerator<Buffer, void>> {
         let cp: InteractiveTerminal | NoninteractiveTerminal = null;
         const queue = createAsyncQueue<Buffer>();
 
@@ -140,7 +159,7 @@ export class TerminalService extends ScryptedDeviceBase implements StreamService
 
                     if (Buffer.isBuffer(message)) {
                         if (cp)
-                            cp.write(message.toString());
+                            cp.write(message);
                         continue;
                     }
 
@@ -154,15 +173,15 @@ export class TerminalService extends ScryptedDeviceBase implements StreamService
                                 cp.sendEOF();
                         } else if ("interactive" in parsed && !cp) {
                             if (parsed.interactive) {
-                                cp = new InteractiveTerminal();
+                                cp = new InteractiveTerminal(parsed.cmd);
                             } else {
-                                cp = new NoninteractiveTerminal();
+                                cp = new NoninteractiveTerminal(parsed.cmd);
                             }
                             registerChildListeners();
                         }
                     } catch {
                         if (cp)
-                            cp.write(message.toString());
+                            cp.write(Buffer.from(message));
                     }
                 }
             }