code: def build(config, services):
      
      filtered_services = {name: service for name, service in services.iteritems() if 'build' in service}
  
      _call_output('docker-compose build {}'.format(' '.join(filtered_services.iterkeys())))
  
      version = _get_version()
  
      for service_name, service_dict in filtered_services.iteritems():
          # Tag with proper version, they're already tagged latest from build
          image = service_dict['image']
          _call('docker tag {image}:latest {image}:{version}'.format(
                  image=image,
                  version=version
              )
          )
docs: Builds images and tags them appropriately.
  
      Where "appropriately" means with the output of:
  
          git describe --tags HEAD
  
      and 'latest' as well (so the "latest" image for each will always be the
      most recently built)