feat: add worker pool mode for process reuse

conf/config.yaml

@@ -13,3 +13,10 @@ proxy:
   socks5: ''
   http: ''
   https: ''
+# Worker pool mode: reuses persistent python/nodejs processes instead of
+# forking a new process for every request.  Disabled by default.
+# Enable with env WORKER_POOL_ENABLED=true or set enabled: true below.
+worker_pool:
+  enabled: false
+  python_workers: 4   # number of pre-warmed Python processes
+  nodejs_workers: 2   # number of pre-warmed Node.js processes

internal/core/runner/nodejs/pool_init_script.js

@@ -0,0 +1,146 @@
+#!/usr/bin/env node
+/**
+ * dify-sandbox Node.js pool worker script.
+ *
+ * Keeps the process alive, reads JSON requests line-by-line from stdin,
+ * executes user code with the same koffi+nodejs.so seccomp isolation as
+ * the original fork-mode prescript.js, then writes a single-line JSON
+ * response to stdout.
+ *
+ * Protocol
+ * --------
+ * stdin  (one JSON line per request):
+ *   {
+ *     "code":           "<b64-xor-encrypted user code>",
+ *     "key":            "<b64 key>",
+ *     "preload":        "<b64-xor-encrypted preload | omit>",
+ *     "enable_network": false,
+ *     "uid":            65537,
+ *     "gid":            65537
+ *   }
+ *
+ * stdout (one JSON line per response):
+ *   { "stdout": "...", "stderr": "...", "error": null | "<msg>" }
+ *
+ * Security note
+ * -------------
+ * DifySeccomp(uid, gid, enable_network) is called ONCE at process startup
+ * (before the request loop begins) via the SANDBOX_UID / SANDBOX_GID /
+ * SANDBOX_ENABLE_NETWORK environment variables set by the Go pool runner.
+ * seccomp filters are one-way — arming them multiple times is not allowed.
+ */
+
+'use strict';
+
+// ---------------------------------------------------------------------------
+// koffi + nodejs.so  (same as prescript.js in fork mode)
+// ---------------------------------------------------------------------------
+
+const LIB_PATH = '/var/sandbox/sandbox-nodejs/nodejs.so';
+
+// Call DifySeccomp once at startup.  uid/gid/enable_network are provided by
+// the Go pool runner via environment variables so they never change per-request.
+const _sandboxUid    = parseInt(process.env.SANDBOX_UID    || '65537', 10);
+const _sandboxGid    = parseInt(process.env.SANDBOX_GID    || '0',     10);
+const _enableNetwork = process.env.SANDBOX_ENABLE_NETWORK === '1';
+
+try {
+    const koffi = require('koffi');
+    const lib = koffi.load(LIB_PATH);
+    const difySeccomp = lib.func('void DifySeccomp(int, int, bool)');
+    difySeccomp(_sandboxUid, _sandboxGid, _enableNetwork);
+} catch (e) {
+    // Running without seccomp (dev / test environment without .so)
+    process.stderr.write('nodejs pool: koffi/DifySeccomp not available: ' + e.message + '\n');
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+function decrypt(buf, key) {
+    const out = Buffer.from(buf);
+    const klen = key.length;
+    for (let i = 0; i < out.length; i++) {
+        out[i] ^= key[i % klen];
+    }
+    return out;
+}
+
+// ---------------------------------------------------------------------------
+// Execute one snippet.
+// Stdout/stderr from user code are captured via console shim + redirect.
+// ---------------------------------------------------------------------------
+
+function execute(codeStr, preload) {
+    const stdoutLines = [];
+    const stderrLines = [];
+    let error = null;
+
+    // Redirect console before calling user code.
+    const origLog   = console.log;
+    const origError = console.error;
+    const origWarn  = console.warn;
+    const origInfo  = console.info;
+
+    console.log   = (...a) => stdoutLines.push(a.map(String).join(' '));
+    console.error = (...a) => stderrLines.push(a.map(String).join(' '));
+    console.warn  = (...a) => stderrLines.push(a.map(String).join(' '));
+    console.info  = (...a) => stdoutLines.push(a.map(String).join(' '));
+
+    try {
+        const fullCode = preload ? preload + '\n\n' + codeStr : codeStr;
+        // eslint-disable-next-line no-eval
+        eval(fullCode); // noqa: eval
+    } catch (e) {
+        error = e.stack || e.message || String(e);
+    } finally {
+        console.log   = origLog;
+        console.error = origError;
+        console.warn  = origWarn;
+        console.info  = origInfo;
+    }
+
+    return {
+        stdout: stdoutLines.join('\n'),
+        stderr: stderrLines.join('\n'),
+        error:  error,
+    };
+}
+
+// ---------------------------------------------------------------------------
+// Main loop
+// ---------------------------------------------------------------------------
+
+process.stderr.write('NODEJS_POOL_READY\n');
+
+const readline = require('readline');
+const rl = readline.createInterface({ input: process.stdin, terminal: false });
+
+rl.on('line', (rawLine) => {
+    const line = rawLine.trim();
+    if (!line) return;
+
+    let response;
+    try {
+        const data = JSON.parse(line);
+
+        const key     = Buffer.from(data.key, 'base64');
+        const code    = decrypt(Buffer.from(data.code, 'base64'), key).toString('utf-8');
+        const preload = data.preload
+            ? decrypt(Buffer.from(data.preload, 'base64'), key).toString('utf-8')
+            : '';
+
+        response = execute(code, preload);
+    } catch (e) {
+        response = {
+            stdout: '',
+            stderr: '',
+            error: 'protocol error: ' + (e.message || String(e)),
+        };
+    }
+
+    process.stdout.write(JSON.stringify(response) + '\n');
+});
+
+rl.on('close', () => process.exit(0));