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Eljay's avatar
Eljay
Icon for Cirrus rankCirrus
Mar 07, 2023

Python code using Parallel-SSH library to connect to F5 BigIP

Hi,
I'm trying to use Parallel-SSH (Python library) to connect to F5 BigIP.

s = SSHClient(<host>,user=<username>, password=<password>, timeout=5, num_retries=1)
res = s.run_command("uname")
for line in res.stdout:
    print(line)

This simple code works perfectly toward a Red Hat server, but it fails toward F5 BigIP:

Here is the error message:
pssh.exceptions.AuthenticationError: ('Authentication error while connecting to %s:%s - %s - retries %s/%s', '<IP address>, 22, AuthenticationError(), 1, 1)

Has anyone gotten this to work with the Parallel-SSH library?
I have already tested Paramiko and that works, but I want to use Parallel-SSH.
devops

10 Replies

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  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    Mar 08, 2023

    For anyone else trying to get this to work on Mac...first:

    1. brew install cmake
    2. (In a venv) pip install ssh2-python
    3. (In a venv) pip install parallel-ssh

    Will post back on details if I can get it talking to BIG-IP. Just took a minute to get through the pip errors for this module.

    UPDATE: Got it working. Works with password or key file if you copied your ssh keys to BIG-IP.

    from pssh.clients import ParallelSSHClient

hosts = ['ltm1.test.local', 'ltm2.test.local']
#client = ParallelSSHClient(hosts, user='root', password='default')
client = ParallelSSHClient(hosts, user='root', pkey='/Users/justme/.ssh/id_rsa')
cmd = 'tmsh list ltm pool'

output = client.run_command(cmd)
for host_out in output:
    for line in host_out.stdout:
        print(line)

### One output for brevity ###
/Users/justme/PycharmProjects/playground/venv/bin/python /Users/justme/PycharmProjects/playground/sshtest.py 
ltm pool nginx-pool {
    members {
        172.16.102.5:http {
            address 172.16.102.5
            session monitor-enabled
            state up
        }
    }
    monitor http
}

Process finished with exit code 0

     

    • Eljay's avatar
      Eljay
      Icon for Cirrus rankCirrus
      Mar 09, 2023

      Thanks, JRahm. Now I see that I wasn't crystal clear, I was using the single host client in Parallel-SSH. See examples for both single and multi host here: https://pypi.org/project/parallel-ssh/ 

      I can adapt my code to this solution as well. But I still wonder if it's a problem with the single host client in the Parallel-SSH library.

      Here's an example that works in Paramiko:

      from  paramiko.client import SSHClient

p = SSHClient()
p.load_system_host_keys()
p.connect('<IP>', username=<username>, password=<password>)
stdin, stdout, stderr = p.exec_command('uname')
print(stdout.read().decode())

      And here's the code using single host client in Parallel-SSH that fails:

      import pssh.exceptions
from pssh.clients import SSHClient

s = SSHClient('<IP>',user=<username>, password=<password>, timeout=5, num_retries=1)
res = s.run_command("uname")
print(res)
for line in res.stdout:
    print(line)

       

      • JRahm's avatar
        JRahm
        Icon for Admin rankAdmin
        Mar 09, 2023

        Hi Eljay ... This also works just fine for me (both with key or password):

        from pssh.clients import SSHClient

host = 'ltm15.test.local'
s = SSHClient(host, user='root', password='default')
# s = SSHClient(host, user='root', pkey='/Users/justme/.ssh/id_rsa')
cmd = 'tmsh list ltm pool'

res = s.run_command(cmd)
print(res)
for line in res.stdout:
    print(line)

        Output:

        /Users/justme/PycharmProjects/playground/venv/bin/python /Users/justme/PycharmProjects/playground/sshtest.py 
	host=ltm15.test.local
	alias=None
	exit_code=None
	channel=<ssh2.channel.Channel object at 0x107c46ef0>
	exception=None
	encoding=utf-8
	read_timeout=None
ltm pool nginx-pool {
    members {
        172.16.102.5:http {
            address 172.16.102.5
            session monitor-enabled
            state up
        }
    }
    monitor http
}

Process finished with exit code 0

        My versions:

        • python: 3.11.2
        • ssh-python: 1.0.0
        • ssh2-python: 1.0.0
        • parallel-ssh: 2.12.0
        • BIG-IP: 15.1.8.1

         

  • MIS's avatar
    MIS
    Icon for Nimbostratus rankNimbostratus
    Jul 02, 2024

    Hello,

    I've tried mimicking the code shared here, but it returns a similar error 

    pssh.exceptions.AuthenticationError: ('Authentication error while connecting to %s:%s - %s - retries %s/%s', '<IP_address>', 22, AuthenticationError(), 3, 3

    A difference I noticed is that my user, when connected through SSH, gets placed in TMSH instead of BASH.

    I've tried 

    from pssh.clients import ParallelSSHClient

hosts = ['<IP_address1>', '<IP_address2>']
client = ParallelSSHClient(hosts, user='<MyUser>',password='<MyPassword>')
cmd = 'show sys clock'

output = client.run_command(cmd)
for host_out in output:
    for line in host_out.stdout:
        print(line)

      and 

    from pssh.clients import SSHClient

host = '<IP_address>'
s = SSHClient(host, user='<MyUser>', password='<MyPassword>')
cmd='show system clock'

res = s.run_command(cmd)

print(res)
for line in res.stdout:
    print(line)

     

    Thanks in advance. All help will be appreciated.

    My versions

    • WSL, Ubuntu 22.04.4 LTS
    • Python          3.10.12
    • parallel-ssh   2.12.0
    • ssh-python    1.0.0
    • ssh2-python  1.0.0
    • BIG-IP          15.1.10.3
    • JRahm's avatar
      JRahm
      Icon for Admin rankAdmin
      Jul 02, 2024

      I'm not able to get ssh2-python installed on either my intel or apple silicon mac currently, erroring out. Might be a little while before I can troubleshoot. I'm guessing since you're in the tmsh shell that this won't work as advertised.

      • MIS's avatar
        MIS
        Icon for Nimbostratus rankNimbostratus
        Jul 03, 2024

        JRahm,

        Thanks for your prompt response.

        In my uneducated and unexperienced state, I was hoping it would work. In the end, it's just a command in the terminal, I thought.

        If it's within my capabilities, I'll be glad to try anything you can suggest.

        I'll see if I can make my user fall into BASH instead of TMSH when SSHing to the F5s.

        Regards,