Rudimentary serial connector

Can run commands on remote host connected to via serial console.
So far no login support.

pyinfra/api/connectors/serial.py

@@ -0,0 +1,83 @@
+import re
+import time
+
+import click
+import serial
+
+from pyinfra import logger
+
+from .util import (
+    get_sudo_password,
+    make_unix_command,
+)
+
+EXECUTION_CONNECTOR = True
+
+
+def make_names_data(hostname):
+    yield '@serial/' + hostname, {'serial_hostname': hostname}, []
+
+
+def connect(state, host):
+    speed = host.data.serial_speed or 9600
+    logger.debug('Connecting to: %s', host.data.serial_hostname)
+    return serial.Serial(host.data.serial_hostname, speed)
+
+
+def run_shell_command(
+    state, host, command,
+    get_pty=False,
+    timeout=None,
+    stdin=None,
+    success_exit_codes=None,
+    print_output=False,
+    print_input=False,
+    return_combined_output=False,
+    use_sudo_password=False,
+    **command_kwargs
+):
+
+    if use_sudo_password:
+        command_kwargs['use_sudo_password'] = get_sudo_password(
+            state, host, use_sudo_password,
+            run_shell_command=run_shell_command,
+            put_file=put_file,
+        )
+
+    command = make_unix_command(command, **command_kwargs)
+    logger.debug('Running command on %s: %s', host.name, command)
+    actual_command = command.get_raw_value() + '\n'
+
+    if print_input:
+        click.echo('{0}>>> {1}'.format(host.print_prefix, command), err=True)
+
+    num_bytes_written = host.connection.write(bytes(actual_command, encoding='ascii'))
+    logger.debug('Num bytes written: %s', num_bytes_written)
+    if host.data.serial_waittime is not None:
+        time.sleep(host.data.serial_waittime)
+    std_out = host.connection.read_all()
+
+    host.connection.write(b'echo $?\n')
+    host.connection.read_until(b'echo $?\r\r\n')
+    time.sleep(1)
+    status_and_rest = host.connection.read_all()
+    try:
+        status = int(re.match(rb'\d+', status_and_rest).group())
+    except Exception:
+        logger.debug('Could not fetch exit status, defaulting to 0')
+        status = 0
+    else:
+        logger.debug('Status: %s', status)
+
+    logger.debug('Command output: %s', std_out)
+    if return_combined_output:
+        return status, [('stdout', std_out)]
+    return status, [std_out], ['']
+
+
+def put_file(*a, **kw):
+    raise NotImplementedError('File transfer per serial line is currently not supported')
+
+
+def get_file(*a, **kw):
+    raise NotImplementedError('File transfer per serial line is currently not supported')

setup.py

@@ -25,6 +25,7 @@
     'jinja2>2,<3',
     'python-dateutil>2,<3',
     'six>1,<2',
+    'pyserial',
     'setuptools',
     'configparser',
     'pywinrm',
@@ -114,6 +115,7 @@ def get_readme_contents():
                 'docker = pyinfra.api.connectors.docker',
                 'local = pyinfra.api.connectors.local',
                 'mech = pyinfra.api.connectors.mech',
+                'serial = pyinfra.api.connectors.serial',
                 'ssh = pyinfra.api.connectors.ssh',
                 'dockerssh = pyinfra.api.connectors.dockerssh',
                 'vagrant = pyinfra.api.connectors.vagrant',