code: function getDockerfileContext(context) {
    const fs = require('fs');
    let files = [];
    let dockerfile = exports.resolveDockerfile(context);
    let file = fs.readFileSync(dockerfile, {encoding: 'utf8'});
    for (let line of file.split('\n')) {
      if (line.match(/^\s*(ADD|COPY).*$/)) {
        let entries = line.split(' ')
          .splice(1)
          .map(val => val.trim())
          .filter(val => val !== '')
          .filter(val => !val.startsWith('http'));
        if (entries[0].startsWith('--chown')) {
          entries = entries.splice(1);
        }
  
        // Array mode
        if (line.indexOf('[') !== -1 && line.indexOf(']') !== -1) {
          let args = JSON.parse(entries.join(' '));
          args.splice(-1);
          files = args
        }
        // Default mode
        else {
          entries.splice(-1);
          files = entries;
        }
      }
    }
  
    let resolvedFiles = [];
    for (let file of files) {
      resolvedFiles = resolvedFiles.concat(glob.sync(path.join(path.dirname(context), file)));
    }
  
    return { context, src: ['Dockerfile', ...resolvedFiles] };
  }
docs: Parses a Dockerfile and looks for sources that may be needed to build this image.
  @param context
  @returns {{context: *, src: *[]}}