_____________________________________________________________________________________________________________________ ERROR at setup of test_unknown_virtual_host ______________________________________________________________________________________________________________________

monkey_patched_dns = None, docker_composer = <conftest.DockerComposer object at 0x7fd3ac7c6460>, docker_compose_file = '/home/user/nginx-proxy/test/test_DOCKER_HOST_unix_socket.yml'

    @pytest.fixture
    def docker_compose(monkey_patched_dns, docker_composer, docker_compose_file):
        """Ensures containers described in a docker compose file are started.

        A custom docker compose file name can be specified by overriding the `docker_compose_file`
        fixture.

        Also, in the case where pytest is running from a docker container, this fixture makes sure
        our container will be attached to all the docker networks.
        """
>       docker_composer.compose(docker_compose_file)

conftest.py:492:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
conftest.py:450: in compose
    docker_compose_up(docker_compose_file)
conftest.py:307: in docker_compose_up
    subprocess.check_output(shlex.split(f'{DOCKER_COMPOSE} -f {compose_file} up -d'), stderr=subprocess.STDOUT)
/usr/local/lib/python3.9/subprocess.py:424: in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
/usr/local/lib/python3.9/subprocess.py:505: in run
    with Popen(*popenargs, **kwargs) as process:
/usr/local/lib/python3.9/subprocess.py:951: in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <Popen: returncode: 255 args: ['docker', 'compose', '-f', '/home/user/nginx-...>, args = ['docker', 'compose', '-f', '/home/user/nginx-proxy/test/test_DOCKER_HOST_unix_socket.yml', 'up', '-d'], executable = b'docker', preexec_fn = None, close_fds = True, pass_fds = ()
cwd = None, env = None, startupinfo = None, creationflags = 0, shell = False, p2cread = -1, p2cwrite = -1, c2pread = 16, c2pwrite = 17, errread = -1, errwrite = 17, restore_signals = True, gid = None, gids = None, uid = None, umask = -1, start_new_session = False

    def _execute_child(self, args, executable, preexec_fn, close_fds,
                       pass_fds, cwd, env,
                       startupinfo, creationflags, shell,
                       p2cread, p2cwrite,
                       c2pread, c2pwrite,
                       errread, errwrite,
                       restore_signals,
                       gid, gids, uid, umask,
                       start_new_session):
        """Execute program (POSIX version)"""

        if isinstance(args, (str, bytes)):
            args = [args]
        elif isinstance(args, os.PathLike):
            if shell:
                raise TypeError('path-like args is not allowed when '
                                'shell is true')
            args = [args]
        else:
            args = list(args)

        if shell:
            # On Android the default shell is at '/system/bin/sh'.
            unix_shell = ('/system/bin/sh' if
                      hasattr(sys, 'getandroidapilevel') else '/bin/sh')
            args = [unix_shell, "-c"] + args
            if executable:
                args[0] = executable

        if executable is None:
            executable = args[0]

        sys.audit("subprocess.Popen", executable, args, cwd, env)

        if (_USE_POSIX_SPAWN
                and os.path.dirname(executable)
                and preexec_fn is None
                and not close_fds
                and not pass_fds
                and cwd is None
                and (p2cread == -1 or p2cread > 2)
                and (c2pwrite == -1 or c2pwrite > 2)
                and (errwrite == -1 or errwrite > 2)
                and not start_new_session
                and gid is None
                and gids is None
                and uid is None
                and umask < 0):
            self._posix_spawn(args, executable, env, restore_signals,
                              p2cread, p2cwrite,
                              c2pread, c2pwrite,
                              errread, errwrite)
            return

        orig_executable = executable

        # For transferring possible exec failure from child to parent.
        # Data format: "exception name:hex errno:description"
        # Pickle is not used; it is complex and involves memory allocation.
        errpipe_read, errpipe_write = os.pipe()
        # errpipe_write must not be in the standard io 0, 1, or 2 fd range.
        low_fds_to_close = []
        while errpipe_write < 3:
            low_fds_to_close.append(errpipe_write)
            errpipe_write = os.dup(errpipe_write)
        for low_fd in low_fds_to_close:
            os.close(low_fd)
        try:
            try:
                # We must avoid complex work that could involve
                # malloc or free in the child process to avoid
                # potential deadlocks, thus we do all this here.
                # and pass it to fork_exec()

                if env is not None:
                    env_list = []
                    for k, v in env.items():
                        k = os.fsencode(k)
                        if b'=' in k:
                            raise ValueError("illegal environment variable name")
                        env_list.append(k + b'=' + os.fsencode(v))
                else:
                    env_list = None  # Use execv instead of execve.
                executable = os.fsencode(executable)
                if os.path.dirname(executable):
                    executable_list = (executable,)
                else:
                    # This matches the behavior of os._execvpe().
                    executable_list = tuple(
                        os.path.join(os.fsencode(dir), executable)
                        for dir in os.get_exec_path(env))
                fds_to_keep = set(pass_fds)
                fds_to_keep.add(errpipe_write)
                self.pid = _posixsubprocess.fork_exec(
                        args, executable_list,
                        close_fds, tuple(sorted(map(int, fds_to_keep))),
                        cwd, env_list,
                        p2cread, p2cwrite, c2pread, c2pwrite,
                        errread, errwrite,
                        errpipe_read, errpipe_write,
                        restore_signals, start_new_session,
                        gid, gids, uid, umask,
                        preexec_fn)
                self._child_created = True
            finally:
                # be sure the FD is closed no matter what
                os.close(errpipe_write)

            self._close_pipe_fds(p2cread, p2cwrite,
                                 c2pread, c2pwrite,
                                 errread, errwrite)

            # Wait for exec to fail or succeed; possibly raising an
            # exception (limited in size)
            errpipe_data = bytearray()
            while True:
                part = os.read(errpipe_read, 50000)
                errpipe_data += part
                if not part or len(errpipe_data) > 50000:
                    break
        finally:
            # be sure the FD is closed no matter what
            os.close(errpipe_read)

        if errpipe_data:
            try:
                pid, sts = os.waitpid(self.pid, 0)
                if pid == self.pid:
                    self._handle_exitstatus(sts)
                else:
                    self.returncode = sys.maxsize
            except ChildProcessError:
                pass

            try:
                exception_name, hex_errno, err_msg = (
                        errpipe_data.split(b':', 2))
                # The encoding here should match the encoding
                # written in by the subprocess implementations
                # like _posixsubprocess
                err_msg = err_msg.decode()
            except ValueError:
                exception_name = b'SubprocessError'
                hex_errno = b'0'
                err_msg = 'Bad exception data from child: {!r}'.format(
                              bytes(errpipe_data))
            child_exception_type = getattr(
                    builtins, exception_name.decode('ascii'),
                    SubprocessError)
            if issubclass(child_exception_type, OSError) and hex_errno:
                errno_num = int(hex_errno, 16)
                child_exec_never_called = (err_msg == "noexec")
                if child_exec_never_called:
                    err_msg = ""
                    # The error must be from chdir(cwd).
                    err_filename = cwd
                else:
                    err_filename = orig_executable
                if errno_num != 0:
                    err_msg = os.strerror(errno_num)
>               raise child_exception_type(errno_num, err_msg, err_filename)
E               FileNotFoundError: [Errno 2] No such file or directory: 'docker'

/usr/local/lib/python3.9/subprocess.py:1837: FileNotFoundError
-------------------------------------------------------------------------------------------------------------------------------- Captured stderr setup ---------------------------------------------------------------------------------------------------------------------------------
INFO:root:docker compose -f /home/user/nginx-proxy/test/test_DOCKER_HOST_unix_socket.yml up -d
---------------------------------------------------------------------------------------------------------------------------------- Captured log setup ----------------------------------------------------------------------------------------------------------------------------------
INFO     root:conftest.py:305 docker compose -f /home/user/nginx-proxy/test/test_DOCKER_HOST_unix_socket.yml up -d

subprocess.check_output(shlex.split(f'{DOCKER_COMPOSE} -f {compose_file} up -d'), stderr=subprocess.STDOUT)