Implement tcat

package.json

@@ -8,7 +8,8 @@
   "main": "index.js",
   "homepage": "https://github.com/uber/tcurl",
   "bin": {
-    "tcurl": "index.js"
+    "tcurl": "index.js",
+    "tcat": "tcat.js"
   },
   "bugs": {
     "url": "https://github.com/uber/tcurl/issues",
@@ -30,7 +31,8 @@
     "safe-json-parse": "^4.0.0",
     "tchannel": "^3.5.19",
     "traverse": "^0.6.6",
-    "xtend": "^4.0.0"
+    "xtend": "^4.0.0",
+    "shon": "^1.1.0"
   },
   "devDependencies": {
     "coveralls": "^2.10.0",

tcat.js

@@ -0,0 +1,135 @@
+#!/usr/bin/env node
+
+// Copyright (c) 2015 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+'use strict';
+
+/*eslint no-console: 0 */
+// tchannel listener interface, a la netcat
+
+var console = require('console');
+var process = require('process');
+var ChildProcess = require('child_process');
+
+var TChannel = require('tchannel');
+
+var Command = require('shon/command');
+var command = new Command('tcat', {
+    peer: '[-p|--peer] <peer> The host:port pair to listen on',
+    // hyperbahn: '[-H|--hyperbahn <hostlist>] Hyperbahn host list to advertise',
+    // thrift: '[-t|--thrift] <file or dir> File or directory with Thrift IDL files',
+    // interactive: '[-i|--interactive] Use interactive stream mode',
+    service: '<service>',
+    endpoint: '<endpoint>',
+    command: '[<command>]',
+    args: '<arg>....',
+    help: '[-h|--help]*'
+});
+
+command.peer.converter = function convertAddress(peer, logger) {
+    var index = peer.lastIndexOf(':');
+    if (index < 0) {
+        logger.error('Expected colon in host:port pair for peer');
+        return null;
+    }
+    var host = peer.slice(0, index);
+    var port = +peer.slice(index + 1);
+    if (port !== port) {
+        logger.error('Expected a numeric port in host:port for peer');
+        return null;
+    }
+    return {host: host, port: port};
+};
+
+function main(args) {
+    var config = command.exec();
+    if (config === 'help') {
+        command._logUsage();
+        return;
+    }
+
+    var server = new TChannel();
+    server
+        .makeSubChannel({serviceName: config.service})
+        .register(config.endpoint, onRequest);
+    server.listen(config.peer.port, config.peer.host, onListening);
+
+    function onListening() {
+        console.log(JSON.stringify({message: 'listening', address: server.hostPort}));
+    }
+
+    function onRequest(req, res, arg2, arg3) {
+        console.log(JSON.stringify(req.extendLogInfo({message: 'request'})));
+        // TODO env inferred from arg2, argscheme dependent
+        var child = ChildProcess.spawn(config.command || 'cat', config.args, {
+            stdio: ['pipe', 'pipe', process.stderr]
+        });
+        child.stdio[0].end(arg3);
+        readString(child.stdio[1], onOutput);
+
+        function onOutput(err, arg3Res) {
+            if (err) {
+                res.sendError(err);
+                return;
+            }
+            console.log(JSON.stringify(req.extendLogInfo({message: 'response', arg2: arg2.toString('utf-8'), arg3: arg3Res})));
+            res.headers.as = req.headers.as;
+            res.sendOk(arg2, arg3Res);
+        }
+    }
+}
+
+function readString(stream, callback) {
+    stream.setEncoding('utf-8');
+    stream.on('data', onData);
+    stream.on('end', onEnd);
+    stream.on('eerror', onError);
+    var done = false;
+    var all = '';
+    function onData(data) {
+        all += data;
+    }
+    function onEnd() {
+        if (done) {
+            return;
+        }
+        done = true;
+        callback(null, all);
+    }
+    function onError(err) {
+        if (done) {
+            return;
+        }
+        done = true;
+        callback(err);
+    }
+    function cancel() {
+        stream.removeListener('data', onData);
+        stream.removeListener('end', onEnd);
+        stream.removeListener('error', onError);
+        done = true;
+        stream = null;
+    }
+    return {cancel: cancel};
+}
+
+if (require.main === module) {
+    main(process.argv);
+}