> -----Original Message-----
> From: Stanislaw Kardach <k...@semihalf.com>
> Sent: Tuesday, September 27, 2022 12:12 PM
> To: Juraj Linkeš <juraj.lin...@pantheon.tech>
> Cc: tho...@monjalon.net; david.march...@redhat.com;
> honnappa.nagaraha...@arm.com; ohily...@iol.unh.edu; lijuan...@intel.com;
> bruce.richard...@intel.com; dev@dpdk.org
> Subject: Re: [PATCH v5 06/10] dts: add ssh connection module
>
> On Mon, Sep 26, 2022 at 02:17:09PM +0000, Juraj Linkeš wrote:
> > The module uses the pexpect python library and implements connection
> > to a node and two ways to interact with the node:
> > 1. Send a string with specified prompt which will be matched after
> > the string has been sent to the node.
> > 2. Send a command to be executed. No prompt is specified here.
> >
> > Signed-off-by: Owen Hilyard <ohily...@iol.unh.edu>
> > Signed-off-by: Juraj Linkeš <juraj.lin...@pantheon.tech>
> > ---
> > dts/framework/exception.py | 48 +++++
> > .../remote_session/session_factory.py | 16 ++
> > dts/framework/remote_session/ssh_session.py | 189 ++++++++++++++++++
> > dts/framework/utils.py | 13 ++
> > 4 files changed, 266 insertions(+)
> > create mode 100644 dts/framework/remote_session/session_factory.py
> > create mode 100644 dts/framework/remote_session/ssh_session.py
> > create mode 100644 dts/framework/utils.py
> >
> > diff --git a/dts/framework/exception.py b/dts/framework/exception.py
> > index 60fd98c9ca..8466990aa5 100644
> > --- a/dts/framework/exception.py
> > +++ b/dts/framework/exception.py
> > @@ -9,6 +9,54 @@
> > """
> >
> >
> > +class TimeoutException(Exception):
> > + """
> > + Command execution timeout.
> > + """
> > +
> > + command: str
> > + output: str
> > +
> > + def __init__(self, command: str, output: str):
> > + self.command = command
> > + self.output = output
> > +
> > + def __str__(self) -> str:
> > + return f"TIMEOUT on {self.command}"
> > +
> > + def get_output(self) -> str:
> > + return self.output
> > +
> > +
> > +class SSHConnectionException(Exception):
> > + """
> > + SSH connection error.
> > + """
> > +
> > + host: str
> > +
> > + def __init__(self, host: str):
> > + self.host = host
> > +
> > + def __str__(self) -> str:
> > + return f"Error trying to connect with {self.host}"
> > +
> > +
> > +class SSHSessionDeadException(Exception):
> > + """
> > + SSH session is not alive.
> > + It can no longer be used.
> > + """
> > +
> > + host: str
> > +
> > + def __init__(self, host: str):
> > + self.host = host
> > +
> > + def __str__(self) -> str:
> > + return f"SSH session with {self.host} has died"
> > +
> > +
> > class ConfigParseException(Exception):
> > """
> > Configuration file parse failure exception.
> > diff --git a/dts/framework/remote_session/session_factory.py
> > b/dts/framework/remote_session/session_factory.py
> > new file mode 100644
> > index 0000000000..ff05df97bf
> > --- /dev/null
> > +++ b/dts/framework/remote_session/session_factory.py
> > @@ -0,0 +1,16 @@
> > +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2022
> > +PANTHEON.tech s.r.o.
> > +# Copyright(c) 2022 University of New Hampshire #
> > +
> > +from framework.config import NodeConfiguration from framework.logger
> > +import DTSLOG
> > +
> > +from .remote_session import RemoteSession from .ssh_session import
> > +SSHSession
> > +
> > +
> > +def create_remote_session(
> > + node_config: NodeConfiguration, name: str, logger: DTSLOG
> > +) -> RemoteSession:
> > + return SSHSession(node_config, name, logger)
> > diff --git a/dts/framework/remote_session/ssh_session.py
> > b/dts/framework/remote_session/ssh_session.py
> > new file mode 100644
> > index 0000000000..e0614e0f90
> > --- /dev/null
> > +++ b/dts/framework/remote_session/ssh_session.py
> > @@ -0,0 +1,189 @@
> > +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2010-2014
> > +Intel Corporation # Copyright(c) 2022 PANTHEON.tech s.r.o.
> > +# Copyright(c) 2022 University of New Hampshire #
> > +
> > +
> > +import time
> > +
> > +from pexpect import pxssh
> > +
> > +from framework.config import NodeConfiguration from
> > +framework.exception import (
> > + SSHConnectionException,
> > + SSHSessionDeadException,
> > + TimeoutException,
> > +)
> > +from framework.logger import DTSLOG
> > +from framework.utils import GREEN, RED
> > +
> > +from .remote_session import RemoteSession
> > +
> > +
> > +class SSHSession(RemoteSession):
> > + """
> > + Module for creating Pexpect SSH sessions to a node.
> > + """
> > +
> > + session: pxssh.pxssh
> > + magic_prompt: str
> > +
> > + def __init__(
> > + self,
> > + node_config: NodeConfiguration,
> > + session_name: str,
> > + logger: DTSLOG,
> > + ):
> > + self.magic_prompt = "MAGIC PROMPT"
> > + super(SSHSession, self).__init__(node_config, session_name,
> > + logger)
> > +
> > + def _connect(self) -> None:
> > + """
> > + Create connection to assigned node.
> > + """
> > + retry_attempts = 10
> > + login_timeout = 20 if self.port else 10
> > + password_regex = (
> > + r"(?i)(?:password:)|(?:passphrase for key)|(?i)(password for
> > .+:)"
> > + )
> > + try:
> > + for retry_attempt in range(retry_attempts):
> > + self.session = pxssh.pxssh(encoding="utf-8")
> > + try:
> > + self.session.login(
> > + self.ip,
> > + self.username,
> > + self.password,
> > + original_prompt="[$#>]",
> > + port=self.port,
> > + login_timeout=login_timeout,
> > + password_regex=password_regex,
> > + )
> > + break
> > + except Exception as e:
> > + print(e)
> > + time.sleep(2)
> > + print(f"Retrying connection: retry number
> > {retry_attempt + 1}.")
> > + else:
> > + raise Exception(f"Connection to {self.hostname}
> > + failed")
> > +
> > + self.logger.info(f"Connection to {self.hostname} succeeded")
> > + self.send_expect("stty -echo", "#")
> > + self.send_expect("stty columns 1000", "#")
> > + except Exception as e:
> > + print(RED(str(e)))
> > + if getattr(self, "port", None):
> > + suggestion = (
> > + f"\nSuggestion: Check if the firewall on
> > {self.hostname} is "
> > + f"stopped.\n"
> > + )
> > + print(GREEN(suggestion))
> > +
> > + raise SSHConnectionException(self.hostname)
> > +
> > + def send_expect_base(self, command: str, prompt: str, timeout: float)
> > ->
> str:
> > + self.clean_session()
> > + original_prompt = self.session.PROMPT
> > + self.session.PROMPT = prompt
> > + self.__sendline(command)
> > + self.__prompt(command, timeout)
> > +
> > + before = self._get_output()
> > + self.session.PROMPT = original_prompt
> > + return before
> > +
> > + def send_expect(
> > + self, command: str, prompt: str, timeout: float = 15, verify: bool
> > = False
> > + ) -> str | int:
> > + try:
> > + ret = self.send_expect_base(command, prompt, timeout)
> > + if verify:
> > + ret_status = self.send_expect_base("echo $?", prompt,
> > timeout)
> > + try:
> > + retval = int(ret_status)
> > + if not retval:
> > + self.logger.error(f"Command: {command} failure!")
> > + self.logger.error(ret)
> > + return retval
> > + else:
> > + return ret
> Just a minor nit. Isn't the verify logic reversed in this commit?
> In V4 "if not retval" was an OK case (returning the output), now it reports an
> error.
Yes, this is a mistake on my part:
0 is False and any other value is True, which is (basically) the opposite of
shell. That means not retval is True when retval = 0 and that shouldn't produce
an error. Thanks for the catch.
> > + except ValueError:
> > + return ret
> > + else:
> > + return ret
> > + except Exception as e:
> > + print(
> > + f"Exception happened in [{command}] and output is "
> > + f"[{self._get_output()}]"
> > + )
> > + raise e
> > +
> > + def _send_command(self, command: str, timeout: float = 1) -> str:
> > + try:
> > + self.clean_session()
> > + self.__sendline(command)
> > + except Exception as e:
> > + raise e
> > +
> > + output = self.get_output(timeout=timeout)
> > + self.session.PROMPT = self.session.UNIQUE_PROMPT
> > + self.session.prompt(0.1)
> > +
> > + return output
> > +
> > + def clean_session(self) -> None:
> > + self.get_output(timeout=0.01)
> > +
> > + def _get_output(self) -> str:
> > + if not self.is_alive():
> > + raise SSHSessionDeadException(self.hostname)
> > + before = self.session.before.rsplit("\r\n", 1)[0]
> > + if before == "[PEXPECT]":
> > + return ""
> > + return before
> > +
> > + def get_output(self, timeout: float = 15) -> str:
> > + """
> > + Get all output before timeout
> > + """
> > + self.session.PROMPT = self.magic_prompt
> > + try:
> > + self.session.prompt(timeout)
> > + except Exception:
> > + pass
> > +
> > + before = self._get_output()
> > + self.__flush()
> > +
> > + self.logger.debug(before)
> > + return before
> > +
> > + def __flush(self) -> None:
> > + """
> > + Clear all session buffer
> > + """
> > + self.session.buffer = ""
> > + self.session.before = ""
> > +
> > + def __prompt(self, command: str, timeout: float) -> None:
> > + if not self.session.prompt(timeout):
> > + raise TimeoutException(command, self._get_output()) from
> > + None
> > +
> > + def __sendline(self, command: str) -> None:
> > + if not self.is_alive():
> > + raise SSHSessionDeadException(self.hostname)
> > + if len(command) == 2 and command.startswith("^"):
> > + self.session.sendcontrol(command[1])
> > + else:
> > + self.session.sendline(command)
> > +
> > + def _close(self, force: bool = False) -> None:
> > + if force is True:
> > + self.session.close()
> > + else:
> > + if self.is_alive():
> > + self.session.logout()
> > +
> > + def is_alive(self) -> bool:
> > + return self.session.isalive()
> > diff --git a/dts/framework/utils.py b/dts/framework/utils.py new file
> > mode 100644 index 0000000000..26b784ebb5
> > --- /dev/null
> > +++ b/dts/framework/utils.py
> > @@ -0,0 +1,13 @@
> > +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2010-2014
> > +Intel Corporation # Copyright(c) 2022 PANTHEON.tech s.r.o.
> > +# Copyright(c) 2022 University of New Hampshire #
> > +
> > +
> > +def RED(text: str) -> str:
> > + return f"\u001B[31;1m{str(text)}\u001B[0m"
> > +
> > +
> > +def GREEN(text: str) -> str:
> > + return f"\u001B[32;1m{str(text)}\u001B[0m"
> > --
> > 2.30.2
> >
>
> Reviewed-by: Stanislaw Kardach <k...@semihalf.com>
>
> --
> Best Regards,
> Stanislaw Kardach
