Strange behavior of connect function when implemented inside a class

[LLIETAER]

Hi, here a little test I made to implement a connection class.

import sys
import asyncio
import logging

from typing import List

import socket
import asyncssh

class Ovc:
    def __init__(self, ip: str):
        self.ip = ip
        self.status: str = "new"
        self.loop = asyncio.get_event_loop()
        self.one_connect()

    def one_connect(self):
        self.loop.create_task(self._one_connect())

    async def _one_connect(self: object) -> None:
        # try
        print("Inside class instance", self.ip)
        self.conn = await asyncssh.connect(self.ip, username="user", password="password",known_hosts=None)
        print('Inside class instance connected')

    def port_open(self, port) -> bool:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        test = sock.connect_ex((self.ip, port))
        result = False
        if test == 0:
            result = True
        sock.close()
        return result

    def __repr__(self):
        return self.ip

    def __str__(self):
        return self.ip


async def main():
    try:
        print('try connect')
        connexion = await \
            asyncssh.connect('172.21.0.12',
                             username='user',
                             password='password',
                             known_hosts=None)
        print('connected')
    except (OSError, asyncssh.Error) as exc:
        print("main exception transmited")
        raise exc
        # sys.exit('SSH connection failed: ' + str(exc))
    else:
        print("connection close")
        connexion.close()

    try:
        print('try connect')
        connexion: asyncssh.SSHClientConnection = await \
            asyncssh.connect('172.21.0.12',
                             username='user',
                             password='password',
                             known_hosts=None)
        print('connected')
    except (OSError, asyncssh.Error) as exc:
        print("main exception transmited")
        raise exc
        # sys.exit('SSH connection failed: ' + str(exc))
    else:
        print("connection close")
        connexion.close()

    print('Federation')
    one = Ovc('172.21.0.12')


if __name__ == "__main__":
    logging.basicConfig()
    logging.getLogger().setLevel(logging.DEBUG)
    asyncssh.set_debug_level(2)
    asyncio.get_event_loop().run_until_complete(main())`

Basically, I implemented a Ovc class to handle a SSH client connection.
In my main() function, I call twice asyncssh.connect on the same server (those 2 calls working as expected) then I create an Ovc instance that call also asyncssh.connect function. At this point the program stop without any errors.
You will find just below the debug 2 run output.

DEBUG:asyncio:Using proactor: IocpProactor
try connect
INFO:asyncssh:Opening SSH connection to 172.21.0.12, port 22
INFO:asyncssh:[conn=0] Connected to SSH server at 172.21.0.12, port 22
INFO:asyncssh:[conn=0]   Local address: 10.232.176.144, port 50513
INFO:asyncssh:[conn=0]   Peer address: 172.21.0.12, port 22
DEBUG:asyncssh:[conn=0] Sending version SSH-2.0-AsyncSSH_2.7.0
DEBUG:asyncssh:[conn=0] Received version SSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
DEBUG:asyncssh:[conn=0] Requesting key exchange
DEBUG:asyncssh:[conn=0]   Key exchange algs: curve25519-sha256,curve25519-sha256@libssh.org,curve448-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,ecdh-sha2-1.3.132.0.10,diffie-hellman-
group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group15-sha512,diffie-hellman-group16-sha512,diffie-hellman-group17-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256@s
sh.com,diffie-hellman-group14-sha1,rsa2048-sha256
DEBUG:asyncssh:[conn=0]   Host key algs: sk-ssh-ed25519-cert-v01@openssh.com,sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ssh-ed448-cert-v01@openssh.com,ecdsa-sha2-nistp52
1-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-1.3.132.0.10-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,sk-ssh-ed25519@openssh.c
om,sk-ecdsa-sha2-nistp256@openssh.com,ssh-ed25519,ssh-ed448,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,ecdsa-sha2-1.3.132.0.10,rsa-sha2-256,rsa-sha2-512,ssh-rsa-sha224@ssh.com,ssh-rsa-sh
a256@ssh.com,ssh-rsa-sha384@ssh.com,ssh-rsa-sha512@ssh.com,ssh-rsa
DEBUG:asyncssh:[conn=0]   Encryption algs: chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
DEBUG:asyncssh:[conn=0]   MAC algs: hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha256-2@ssh.com,hmac-sha224@ssh.com,h
mac-sha256@ssh.com,hmac-sha384@ssh.com,hmac-sha512@ssh.com
DEBUG:asyncssh:[conn=0]   Compression algs: zlib@openssh.com,none
DEBUG:asyncssh:[conn=0] Received key exchange request
DEBUG:asyncssh:[conn=0]   Key exchange algs: diffie-hellman-group-exchange-sha256,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,curve25519-sha256@libssh.org
DEBUG:asyncssh:[conn=0]   Host key algs: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
DEBUG:asyncssh:[conn=0]   Client to server:
DEBUG:asyncssh:[conn=0]     Encryption algs: aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     MAC algs: hmac-sha2-256,hmac-sha2-512,umac-128@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
DEBUG:asyncssh:[conn=0]     Compression algs: none,zlib@openssh.com
DEBUG:asyncssh:[conn=0]   Server to client:
DEBUG:asyncssh:[conn=0]     Encryption algs: aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     MAC algs: hmac-sha2-256,hmac-sha2-512,umac-128@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
DEBUG:asyncssh:[conn=0]     Compression algs: none,zlib@openssh.com
DEBUG:asyncssh:[conn=0] Beginning key exchange
DEBUG:asyncssh:[conn=0]   Key exchange alg: curve25519-sha256@libssh.org
DEBUG:asyncssh:[conn=0]   Client to server:
DEBUG:asyncssh:[conn=0]     Encryption alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     MAC alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     Compression alg: zlib@openssh.com
DEBUG:asyncssh:[conn=0]   Server to client:
DEBUG:asyncssh:[conn=0]     Encryption alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     MAC alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=0]     Compression alg: zlib@openssh.com
DEBUG:asyncssh:[conn=0] Requesting service ssh-userauth
DEBUG:asyncssh:[conn=0] Completed key exchange
DEBUG:asyncssh:[conn=0] Received extension info
DEBUG:asyncssh:[conn=0]   server-sig-algs: ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
DEBUG:asyncssh:[conn=0] Request for service ssh-userauth accepted
INFO:asyncssh:[conn=0] Beginning auth for user iusr_simplivitymonitor@vsphere.local
DEBUG:asyncssh:[conn=0] Received authentication banner
DEBUG:asyncssh:[conn=0] Remaining auth methods: publickey,password
DEBUG:asyncssh:[conn=0] Preferred auth methods: gssapi-keyex,gssapi-with-mic,hostbased,publickey,keyboard-interactive,password
DEBUG:asyncssh:[conn=0] Trying public key auth with rsa-sha2-256 key
DEBUG:asyncssh:[conn=0] Remaining auth methods: publickey,password
DEBUG:asyncssh:[conn=0] Preferred auth methods: gssapi-keyex,gssapi-with-mic,hostbased,publickey,keyboard-interactive,password
DEBUG:asyncssh:[conn=0] Trying password auth
INFO:asyncssh:[conn=0] Auth for user iusr_simplivitymonitor@vsphere.local succeeded
connected
connection close
INFO:asyncssh:[conn=0] Closing connection
INFO:asyncssh:[conn=0] Sending disconnect: Disconnected by application (11)
try connect
INFO:asyncssh:Opening SSH connection to 172.21.0.12, port 22
INFO:asyncssh:[conn=0] Connection closed
INFO:asyncssh:[conn=1] Connected to SSH server at 172.21.0.12, port 22
INFO:asyncssh:[conn=1]   Local address: 10.232.176.144, port 50514
INFO:asyncssh:[conn=1]   Peer address: 172.21.0.12, port 22
DEBUG:asyncssh:[conn=1] Sending version SSH-2.0-AsyncSSH_2.7.0
DEBUG:asyncssh:[conn=1] Received version SSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
DEBUG:asyncssh:[conn=1] Requesting key exchange
DEBUG:asyncssh:[conn=1]   Key exchange algs: curve25519-sha256,curve25519-sha256@libssh.org,curve448-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,ecdh-sha2-1.3.132.0.10,diffie-hellman-
group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group15-sha512,diffie-hellman-group16-sha512,diffie-hellman-group17-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256@s
sh.com,diffie-hellman-group14-sha1,rsa2048-sha256
DEBUG:asyncssh:[conn=1]   Host key algs: sk-ssh-ed25519-cert-v01@openssh.com,sk-ecdsa-sha2-nistp256-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ssh-ed448-cert-v01@openssh.com,ecdsa-sha2-nistp52
1-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-1.3.132.0.10-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,sk-ssh-ed25519@openssh.c
om,sk-ecdsa-sha2-nistp256@openssh.com,ssh-ed25519,ssh-ed448,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256,ecdsa-sha2-1.3.132.0.10,rsa-sha2-256,rsa-sha2-512,ssh-rsa-sha224@ssh.com,ssh-rsa-sh
a256@ssh.com,ssh-rsa-sha384@ssh.com,ssh-rsa-sha512@ssh.com,ssh-rsa
DEBUG:asyncssh:[conn=1]   Encryption algs: chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
DEBUG:asyncssh:[conn=1]   MAC algs: hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha256-2@ssh.com,hmac-sha224@ssh.com,h
mac-sha256@ssh.com,hmac-sha384@ssh.com,hmac-sha512@ssh.com
DEBUG:asyncssh:[conn=1]   Compression algs: zlib@openssh.com,none
DEBUG:asyncssh:[conn=1] Received key exchange request
DEBUG:asyncssh:[conn=1]   Key exchange algs: diffie-hellman-group-exchange-sha256,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,curve25519-sha256@libssh.org
DEBUG:asyncssh:[conn=1]   Host key algs: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
DEBUG:asyncssh:[conn=1]   Client to server:
DEBUG:asyncssh:[conn=1]     Encryption algs: aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     MAC algs: hmac-sha2-256,hmac-sha2-512,umac-128@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
DEBUG:asyncssh:[conn=1]     Compression algs: none,zlib@openssh.com
DEBUG:asyncssh:[conn=1]   Server to client:
DEBUG:asyncssh:[conn=1]     Encryption algs: aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     MAC algs: hmac-sha2-256,hmac-sha2-512,umac-128@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com
DEBUG:asyncssh:[conn=1]     Compression algs: none,zlib@openssh.com
DEBUG:asyncssh:[conn=1] Beginning key exchange
DEBUG:asyncssh:[conn=1]   Key exchange alg: curve25519-sha256@libssh.org
DEBUG:asyncssh:[conn=1]   Client to server:
DEBUG:asyncssh:[conn=1]     Encryption alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     MAC alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     Compression alg: zlib@openssh.com
DEBUG:asyncssh:[conn=1]   Server to client:
DEBUG:asyncssh:[conn=1]     Encryption alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     MAC alg: chacha20-poly1305@openssh.com
DEBUG:asyncssh:[conn=1]     Compression alg: zlib@openssh.com
DEBUG:asyncssh:[conn=1] Requesting service ssh-userauth
DEBUG:asyncssh:[conn=1] Completed key exchange
DEBUG:asyncssh:[conn=1] Received extension info
DEBUG:asyncssh:[conn=1]   server-sig-algs: ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
DEBUG:asyncssh:[conn=1] Request for service ssh-userauth accepted
INFO:asyncssh:[conn=1] Beginning auth for user iusr_simplivitymonitor@vsphere.local
DEBUG:asyncssh:[conn=1] Received authentication banner
DEBUG:asyncssh:[conn=1] Remaining auth methods: publickey,password
DEBUG:asyncssh:[conn=1] Preferred auth methods: gssapi-keyex,gssapi-with-mic,hostbased,publickey,keyboard-interactive,password
DEBUG:asyncssh:[conn=1] Trying public key auth with rsa-sha2-256 key
DEBUG:asyncssh:[conn=1] Remaining auth methods: publickey,password
DEBUG:asyncssh:[conn=1] Preferred auth methods: gssapi-keyex,gssapi-with-mic,hostbased,publickey,keyboard-interactive,password
DEBUG:asyncssh:[conn=1] Trying password auth
INFO:asyncssh:[conn=1] Auth for user iusr_simplivitymonitor@vsphere.local succeeded
connected
connection close
INFO:asyncssh:[conn=1] Closing connection
INFO:asyncssh:[conn=1] Sending disconnect: Disconnected by application (11)
Federation
INFO:asyncssh:[conn=1] Connection closed
Inside class instance 172.21.0.12
INFO:asyncssh:Opening SSH connection to 172.21.0.12, port 22

Process finished with exit code 0

It looks very strange to me, have you any ideas to move forward ? thanks in advance.

[ronf]

I think your problem here is that you are using run_until_complete() on main(). So, as soon as main() exits, the event loop is closed. Even though the Ovc() object might be trying to make additional connections, the event loop won't be running long enough to let that happen. You need to either follow the run_until_complete() with a run_forever() call after that while the event loop is still open, or you need some other way for main() to remain active (possibly waiting on a Future) until you are ready for the event loop to close and the client process to exit.

[LLIETAER]

You were right Ron, I manage to make work it with your excellent advices

def main():
    try:
        loop = asyncio.get_event_loop()
        print('Federation')
        one = Ovc('172.21.0.12')
        loop.run_forever()

    except KeyboardInterrupt:
        print('Stopping event loop')
        loop.stop()

if __name__ == "__main__":
    logging.basicConfig()
    logging.getLogger().setLevel(logging.DEBUG)
    asyncssh.set_debug_level(2)
    main()

Because my main() function became standard (not a coro anymore), I think what I really need is to have an awaitable init function. I found an interesting article.
https://newbedev.com/how-to-set-class-attribute-with-await-in-init

and a library
https://pypi.org/project/async-class/

Many thanks, Ron to pull me out of the fog.
I may still have a too synchronous mind ;-)

[ronf]

Glad to hear you got it working!

As for async init functions, I'm in the camp that recommends using async factory functions for that, as the author of the first article suggested. I kind of like knowing that my object initialization finishes all at once from the event loop's perspective, before any other async operations can run. However, I'll admit that puts an extra burden on the callers to know to use the factory function.