Source code for django_remote_submission.wrapper.local

''' Provides a Local Wrapper to run the commands in the local machine
without the need of a sshd server.

The goal with this class is to also be able to provide a ``LocalWrapper``
which works with the local file system, so that tests can be run on
continuous integration servers.
'''

import logging
import os
import os.path
from collections import namedtuple
from subprocess import PIPE, Popen

from django.utils.timezone import now

from .remote import RemoteWrapper

logger = logging.getLogger(__name__)


class LocalWrapper(RemoteWrapper):
    """
    This class extends and modify the functionality of the ``RemoteWrapper``.
    It has the same functionality but does not perform any SSH connections.
    """

    def __init__(self, *args, **kwargs):
        super(LocalWrapper, self).__init__(*args, **kwargs)
        self.workdir = os.getcwd()

    def connect(self, *args, **kwargs):
        return self

    def __enter__(self):
        return self

    def __exit__(self, *args, **kwargs):
        pass

    def close(self, *args, **kwargs):
        pass

    def chdir(self, remote_directory):
        self.workdir = os.path.join(self.workdir, remote_directory)

    def open(self, filename, mode):
        # create the directory + subdirectories in case they don't exist
        try:
            os.makedirs(self.workdir)
        except OSError:
            # In case the directy(ies) exist
            pass
        return open(os.path.join(self.workdir, filename), mode)

    def listdir_attr(self):
        Attr = namedtuple('Attr', ['filename', 'st_mtime'])

        results = []
        for filename in os.listdir(self.workdir):
            stat = os.stat(os.path.join(self.workdir, filename))

            results.append(Attr(
                filename=filename,
                st_mtime=stat.st_mtime,
            ))

        return results

    def exec_command(self, args, workdir, timeout=None, stdout_handler=None,
                     stderr_handler=None):
        '''
        Altouhgh Log.LIVE is possible, the Local does not support True Live Log.
        In local for large outputs, it looks like stdXXX_handle takes too long
        and the buffer of the process over runs and the log gets truncated
        '''
        if timeout is not None:
            args = ['timeout', '{}s'.format(timeout.total_seconds())] + args

        logger.info('{!r}'.format(args))
        process = Popen(args, stdout=PIPE, stderr=PIPE,
                        cwd=self.workdir, universal_newlines=True)

        stdout, stderr = process.communicate()

        for line in stdout.split('\n'):
            if line.strip():
                current_time = now()
                stdout_handler(current_time, line+'\n')
        
        for line in stderr.split('\n'):
            if line.strip():
                current_time = now()
                stderr_handler(current_time, line+'\n')

        logger.debug('Done reading the process stdout / stderr')

        return process.returncode == 0