1 | var express = require('express');
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2 | var bodyParser = require('body-parser');
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3 | var util = require('util');
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4 | var fs = require('fs');
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5 | var Promise = require('bluebird');
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6 | var spawn = require('child_process').spawn;
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7 | var through = require('through2').obj;
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8 | var stream = require('stream');
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9 | var uuid = require('uuid');
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10 |
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11 | var cwd = process.cwd();
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12 |
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13 | module.exports = makeApp;
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14 | module.exports.NotFound = NotFound;
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15 | module.exports.UnprocessableEntity = UnprocessableEntity;
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16 |
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17 |
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18 | function NotFound(message) {
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19 | Error.call(this);
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20 | this.message = message;
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21 | this.statusCode = 404;
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22 | }
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23 | util.inherits(NotFound, Error);
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24 |
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25 | function UnprocessableEntity(message) {
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26 | Error.call(this);
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27 | this.message = message;
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28 | this.statusCode = 422;
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29 | }
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30 | util.inherits(UnprocessableEntity, Error);
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31 |
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32 | function logWebError(req, err) {
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33 | console.error(req.originalUrl, err.stack || err);
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34 | }
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35 |
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36 | function catchWebErrors(res) {
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37 | return function(err){
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38 | if (err.statusCode) {
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39 | res.sendStatus(err.statusCode);
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40 | if (err.statusCode >= 500) {
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41 | logWebError(req, err);
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42 | }
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43 | } else {
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44 | res.sendStatus(500);
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45 | logWebError(res, err);
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46 | }
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47 | };
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48 | }
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49 |
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50 | function api(fn){
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51 | return function(req, res){
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52 | Promise.resolve()
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53 | .then(function(){
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54 | return fn(req);
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55 | })
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56 | .then(function(result){
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57 | res.json(result);
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58 | })
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59 | .catch(catchWebErrors(res));
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60 | };
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61 | }
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62 |
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63 | function isString(thing) {
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64 | return typeof thing === 'string';
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65 | }
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66 |
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67 | function idDir(id) {
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68 | return cwd+'/remote-task-'+id;
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69 | }
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70 |
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71 | function makeApp() {
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72 | var tasks = {};
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73 | var stdin = {};
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74 |
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75 | function getTasks() {
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76 | return tasks;
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77 | }
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78 |
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79 | function getTask(req) {
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80 | if (typeof tasks[req.params.id] === 'undefined') {
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81 | throw new NotFound('task not found');
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82 | }
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83 |
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84 | return tasks[req.params.id];
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85 | }
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86 |
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87 | function createTask(req) {
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88 | if (typeof req.body !== 'object') {
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89 | throw new UnprocessableEntity('trying to create task without a body');
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90 | }
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91 |
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92 | var commands = req.body.commands || [];
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93 | if (!Array.isArray(commands) || commands.filter(isString).length !== commands.length) {
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94 | throw new UnprocessableEntity('req.body.commands must be an array of strings');
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95 | }
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96 |
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97 | var timeout = req.body.timeout;
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98 | if (typeof timeout !== 'undefined' && typeof timeout !== 'number') {
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99 | throw new UnprocessableEntity('req.body.timeout must be a number, or undefined');
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100 | }
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101 | timeout = timeout || 0;
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102 |
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103 | var shell = spawn('bash');
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104 | var pid = shell.pid;
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105 | var id = uuid.v4();
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106 |
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107 | stdin[id] = new stream.PassThrough();
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108 |
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109 | fs.mkdir(idDir(id), function(err){
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110 | if (err) {
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111 | console.error('Error making directory', idDir(id), err);
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112 | }
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113 |
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114 | shell.stdout.pipe(fs.createWriteStream(idDir(id)+'/stdout.log'));
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115 | shell.stderr.pipe(fs.createWriteStream(idDir(id)+'/stderr.log'));
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116 |
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117 | stdin[id].pipe(shell.stdin);
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118 | stdin[id].pipe(fs.createWriteStream(idDir(id)+'/stdin.log'));
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119 | stdin[id].on('end', function(){
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120 | delete stdin[id];
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121 | })
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122 | });
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123 |
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124 | commands.forEach(function(cmd){
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125 | stdin[id].write(cmd+'\n');
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126 | });
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127 |
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128 | if (req.body.end === true) {
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129 | stdin[id].end();
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130 | }
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131 |
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132 | var task = tasks[id] = {
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133 | id: id,
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134 | pid: pid,
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135 | startTime: Date.now(),
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136 | running: true,
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137 | writable: req.body.end !== true,
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138 | errors: []
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139 | };
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140 | if (timeout) {
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141 | task.timeout = timeout;
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142 | }
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143 |
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144 | shell.on('error', function(err){
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145 | task.errors.push(err.stack || err);
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146 | });
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147 |
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148 | var killTimeout;
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149 | if (timeout) {
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150 | killTimeout = setTimeout(function(){
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151 | stopTaskById(id).catch(function(err) {
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152 | console.error('failed to kill '+id+' after '+timeout+'ms timeout', err && err.stack ? err.stack : err);
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153 | });
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154 | }, timeout);
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155 | }
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156 |
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157 | shell.on('exit', function(code, signal){
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158 | if (killTimeout) {
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159 | clearTimeout(killTimeout);
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160 | }
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161 | task.running = false;
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162 | task.code = code;
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163 | task.signal = signal;
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164 | });
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165 |
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166 | return task;
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167 | }
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168 |
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169 | function addCommands(req) {
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170 | if (typeof req.body !== 'object') {
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171 | throw new UnprocessableEntity('trying to create task without a body');
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172 | }
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173 |
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174 | if (!/^[0-9a-z\-]{36}$/.test(req.params.id)) {
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175 | throw new UnprocessableEntity('req.body.id must be a uuid');
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176 | }
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177 | var id = req.params.id;
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178 |
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179 | var commands = req.body.commands || [];
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180 | if (!Array.isArray(commands) || commands.filter(isString).length !== commands.length) {
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181 | throw new UnprocessableEntity('req.body.commands must be an array of strings');
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182 | }
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183 |
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184 | var task = tasks[id];
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185 | if (typeof task === 'undefined') {
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186 | throw new NotFound('task not found');
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187 | }
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188 |
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189 | if (!task.writable) {
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190 | throw new Error('trying to write to a closed stdin');
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191 | }
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192 |
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193 | if (typeof stdin[id] === 'undefined' || !(stdin[id] instanceof stream.Stream)) {
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194 | throw new Error('invalid stdin stream');
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195 | }
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196 |
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197 | commands.forEach(function(cmd){
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198 | stdin[id].write(cmd+'\n');
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199 | });
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200 |
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201 | if (req.body.end === true) {
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202 | tasks[id].writable = false;
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203 | stdin[id].end();
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204 | delete stdin[id];
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205 | }
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206 |
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207 | return task;
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208 | }
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209 |
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210 | function stopTaskById(id) {
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211 | return new Promise(function(resolve, reject){
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212 | var timeouts = [];
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213 | var task = tasks[id];
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214 | if (!task) {
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215 | throw new Error('no such task '+id);
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216 | }
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217 |
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218 | function forget(){
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219 | clearInterval(monitor);
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220 | timeouts.forEach(clearTimeout);
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221 | }
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222 |
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223 | function check(){
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224 | try {
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225 | process.kill(task.pid, 0);
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226 | } catch (err) {
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227 | if (err.message !== 'kill ESRCH') {
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228 | throw err;
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229 | }
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230 | task.writable = false;
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231 | delete stdin[id];
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232 | forget();
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233 | resolve();
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234 | return true;
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235 | }
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236 | }
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237 |
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238 | var monitor = setInterval(check, 20);
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239 |
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240 | if (check()) return;
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241 | process.kill(task.pid, 'SIGHUP');
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242 | if (check()) return;
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243 |
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244 | timeouts.push(setTimeout(function(){
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245 | process.kill(task.pid, 'SIGTERM');
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246 | check();
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247 | }, 5000));
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248 |
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249 | timeouts.push(setTimeout(function(){
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250 | process.kill(task.pid, 'SIGKILL');
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251 | check();
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252 | }, 10000));
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253 |
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254 | timeouts.push(setTimeout(function(){
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255 | forget();
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256 | reject(new Error('unable to kill process '+task.pid));
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257 | }, 15000));
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258 | });
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259 | }
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260 |
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261 | function stopTask(req) {
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262 | if (!/^[0-9a-z\-]{36}$/.test(req.params.id)) {
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263 | throw new UnprocessableEntity('req.body.id must be a uuid');
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264 | }
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265 | var id = req.params.id;
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266 |
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267 | return stopTaskById(id);
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268 | }
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269 |
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270 | function stopTasks() {
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271 | var ids = Object.keys(tasks);
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272 |
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273 | return Promise.all(ids.map(stopTaskById));
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274 | }
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275 |
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276 | var app = express();
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277 | app.use(bodyParser.json());
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278 |
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279 | app.get('/tasks', api(getTasks));
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280 | app.get('/tasks/:id', api(getTask));
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281 | app.post('/tasks', api(createTask));
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282 | app.post('/tasks/:id', api(addCommands));
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283 | app.delete('/tasks', api(stopTasks));
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284 | app.delete('/tasks/:id', api(stopTask));
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285 |
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286 | return app;
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287 | }
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