(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/server/lib/SafePythonComponent.ts

@@ -0,0 +1,73 @@
+import {LocalPlugin} from 'app/common/plugin';
+import {BaseComponent, createRpcLogger} from 'app/common/PluginInstance';
+import {GristServer} from 'app/server/lib/GristServer';
+import {ISandbox} from 'app/server/lib/ISandbox';
+import * as log from 'app/server/lib/log';
+import {IMsgCustom, IMsgRpcCall} from 'grain-rpc';
+import * as path from 'path';
+
+// TODO safePython component should be able to call other components function
+// TODO calling a function on safePython component with a name that was not register chould fail
+// gracefully.
+
+/**
+ * The safePython component used by a PluginInstance.
+ *
+ * It uses `NSandbox` implementation of rpc for calling methods within the sandbox.
+ */
+export class SafePythonComponent extends BaseComponent {
+
+  private _sandbox: ISandbox;
+  private _logMeta: log.ILogMeta;
+
+  // safe python component does not need pluginInstance.rpc because it is not possible to forward
+  // calls to other component from within python
+  constructor(private _localPlugin: LocalPlugin,
+              private _mainPath: string, private _tmpDir: string,
+              docName: string, private _server: GristServer,
+              rpcLogger = createRpcLogger(log, `PLUGIN ${_localPlugin.id}/${_mainPath} SafePython:`)) {
+    super(_localPlugin.manifest, rpcLogger);
+    this._logMeta = {plugin: _localPlugin.id, docId: docName};
+  }
+
+  /**
+   * `SafePythonComponent` activation creates the Sandbox. Throws if the plugin has no `safePyton`
+   * components.
+   */
+  protected async activateImplementation(): Promise<void> {
+    if (!this._tmpDir) {
+      throw new Error("Sanbox should have a tmpDir");
+    }
+    this._sandbox = this._server.create.NSandbox({
+      entryPoint: this._mainPath,
+      sandboxMount: path.join(this._localPlugin.path, 'sandbox'),
+      importMount: this._tmpDir,
+      logTimes: true,
+      logMeta: this._logMeta,
+    });
+  }
+
+  protected async deactivateImplementation(): Promise<void> {
+    log.info('SafePython deactivating ...');
+    if (!this._sandbox) {
+      log.info('  sandbox is undefined');
+    }
+    if (this._sandbox) {
+      await this._sandbox.shutdown();
+      log.info('SafePython done deactivating the sandbox');
+      delete this._sandbox;
+    }
+  }
+
+  protected doForwardCall(c: IMsgRpcCall): Promise<any> {
+    if (!this._sandbox) { throw new Error("Component should have be activated"); }
+    const {meth, iface, args} = c;
+    const funcName = meth === "invoke" ? iface : iface + "." + meth;
+    return this._sandbox.pyCall(funcName, ...args);
+  }
+
+  protected doForwardMessage(c: IMsgCustom): Promise<any> {
+    throw new Error("Forwarding messages to python sandbox is not supported");
+  }
+
+}