worker.js

'use strict';

var fs = require('fs');
var path = require('path');

function shellCommand(command) {
  if (!command || !command.replace(/#[^\n]*/g, '').trim().length) {
    return;
  }
  
  return {
    command: 'sh',
    args: ['-x', '-c', command]
  };
}

module.exports = {
  init: function (config, job, context, done) {
    var venvDir = path.join(context.baseDir, '.venv');
    var test, runtime;
    
    if (config) {
      if (config.test !== 'none') {
        test = config.test
      }
      if (config.runtime !== 'none') {
        runtime = config.runtime
      } else {
        runtime = '2'
      }
    }
    
    var defaultPrepare = function (context, done) {
        if (!fs.existsSync(path.join(context.dataDir, 'requirements.txt'))) {
          // skip if default and no requirements.txt exists
          // we assume that if you're configuring your own, you'll ensure the file exists
          return done(null, true);
        }
        
        context.cmd('pip install -r requirements.txt', function (err) {
          done(err, true);
        });
    }
    
    var prepare = defaultPrepare;
    
    if (config && config.prepare) {
      prepare = shellCommand(config.prepare);
    }
    
    done(null, {
      path: [path.join(venvDir, 'bin')],
      environment: 'virtualenv -p python' + runtime + ' ' + venvDir,
      prepare: prepare,
      test: test
    });
  },
  autodetect: {
    filename: 'requirements.txt',
    exists: true,
    language: 'python',
    framework: null
  }
};