view contrib/automation/hgautomation/ssh.py @ 48652:6fd9a17c32ab

requirements: add an official `REVLOG_COMPRESSION_ZSTD` const

Such constant was missing and its value was missing from the set of requirements
that needs to be preserved through stream clone. This did not had any
consequence yet as the "bundle 2 does not filter its requirements" is shadowing
the issue.

However we are now in a situation where we can fix this issue. So lets do it
next.

With the preparation work on test, changing the streamreqs value only impact two
tests, where checking the full value seems to remains relevant.

Important note: Since older version of Mercurial used the old `supportedformat`
class attribute to check for stream requirement they supported, older version
will consider this requirements to prevent them from using streaming clone. Even
as they support this requirements for years. Pack for stable will be send to fix
it, but they will have to be backported to older version if needed.

Differential Revision: https://phab.mercurial-scm.org/D12083

# ssh.py - Interact with remote SSH servers
#
# Copyright 2019 Gregory Szorc <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

# no-check-code because Python 3 native.

import socket
import time
import warnings

from cryptography.utils import CryptographyDeprecationWarning
import paramiko


def wait_for_ssh(hostname, port, timeout=60, username=None, key_filename=None):
    """Wait for an SSH server to start on the specified host and port."""

    class IgnoreHostKeyPolicy(paramiko.MissingHostKeyPolicy):
        def missing_host_key(self, client, hostname, key):
            return

    end_time = time.time() + timeout

    # paramiko triggers a CryptographyDeprecationWarning in the cryptography
    # package. Let's suppress
    with warnings.catch_warnings():
        warnings.filterwarnings(
            'ignore', category=CryptographyDeprecationWarning
        )

        while True:
            client = paramiko.SSHClient()
            client.set_missing_host_key_policy(IgnoreHostKeyPolicy())
            try:
                client.connect(
                    hostname,
                    port=port,
                    username=username,
                    key_filename=key_filename,
                    timeout=5.0,
                    allow_agent=False,
                    look_for_keys=False,
                )

                return client
            except socket.error:
                pass
            except paramiko.AuthenticationException:
                raise
            except paramiko.SSHException:
                pass

            if time.time() >= end_time:
                raise Exception('Timeout reached waiting for SSH')

            time.sleep(1.0)


def exec_command(client, command):
    """exec_command wrapper that combines stderr/stdout and returns channel"""
    chan = client.get_transport().open_session()

    chan.exec_command(command)
    chan.set_combine_stderr(True)

    stdin = chan.makefile('wb', -1)
    stdout = chan.makefile('r', -1)

    return chan, stdin, stdout