Pull Output from read_channel to use in another command

[m1ndn1nj4]

Hello,

Is there a way to pull information from the output of a show command to use in another command?

For instance, say I needed to run the following commands:

router1#show int description | i Prod
Tu12345                        up             up       Prod to router2 via Gi0/0/0
router1#
router1#show run int Tu12345 | i dest 
 tunnel destination 1.2.2.1
router1#
router1#ping 1.2.2.1 source loopback0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.2.2.1, timeout is 2 seconds:
Packet sent with a source address of 1.1.1.1 
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/12/19 ms
router1#
router1#

If I needed the Tu12345 to use in another command would there be a way to get just the value Tu12345 to use in another command to send to a device, caveat being that the numbers after Tu would be completely random. So then I could send show run int Tu12345 | in dest

So what my end goal would be is to have something like this:

net_connect.send_command('show int description | i Prod)
net_connect.send_command(f'show run int Tu{Tunnel_Number_From_Previous_Command} | include dest')
net_connect.send_command(f'ping {Tunnel_IP_Destination_From_Previous_Command} source loopback0')

Is this possible? Thanks in advance!

[ktbyers]

Yes, just get the result back from the first show command; parse the output to extract the interface. Then use some form of f-strings or .format() method to generate the next command using the interface you saved in the previous command.

For parsing, you can look at regular expressions or just a straight .split() call and extract the first field. In other situations, you can use TextFSM or Genie, but those solutions probably won't work here.

[m1ndn1nj4]

So would something like this work?

            elif "cisco_ios" in platform and "co-acc-v" in role:
                print(f"Running verification commands for host {hostname}...")
                for commands in verification_commands["cisco_ios"]["co-acc-v"]:
                    logfile.write(ssh_connection.send_command(
                        commands, read_timeout=300.0, strip_command=False, strip_prompt=False
                    ))
                    time.sleep(1)
                tunnel = logfile.write(ssh_connection.send_command(
                    'sh int desc | i Prod to', read_timeout=300.0, strip_command=False, strip_prompt=False
                ))
                tu_int = re.match(r'Tu[0-9]+', tunnel)
                tunnel_destination = logfile.write(ssh_connection.send_command(
                    f'sh run int {tu_int} | i dest', read_timeout=300.0, strip_command=False, strip_prompt=False
                ))
                dest_ip = re.match(r'([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})', tunnel_destination)
                logfile.write(ssh_connection.send_command(
                    f'ping ip {dest_ip} repeat 1000 size 1400 df source loopback0',
                    read_timeout=300.0, strip_command=False, strip_prompt=False
                ))

[m1ndn1nj4]

Had to change my code up a little to get it to work, but this is doing the trick for me now:

            elif "cisco_ios" in platform and "co-acc-v" in role:
                print(f"Running verification commands for host {hostname}...")
                for commands in verification_commands["cisco_ios"]["co-acc-v"]:
                    output = ssh_connection.send_command(
                        commands,
                        read_timeout=500.0,
                        strip_command=False,
                        strip_prompt=False,
                    )
                    time.sleep(1)
                    results = f"MCM Verification Checks/{mcm}/{stage}-Checks/{hostname}-{mcm}-{stage}-Checks.txt"
                    with open(results, "a") as fp:
                        fp.write(output)
                output += ssh_connection.send_command(
                    "sh int desc | i Prod to", strip_command=False, strip_prompt=False
                )
                time.sleep(1)
                tu_int = re.search(r"Tu([0-9]+)", output)
                output += ssh_connection.send_command(
                    f"sh run int {tu_int.group()} | i dest",
                    read_timeout=500.0,
                    strip_command=False,
                    strip_prompt=False,
                )
                time.sleep(1)
                dest_ip = re.search(
                    r"([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})", output
                )
                output += ssh_connection.send_command(
                    f"ping ip {dest_ip.group()} repeat 1000 size 1400 df source loopback0",
                    read_timeout=500.0,
                    strip_command=False,
                    strip_prompt=False,
                )
                time.sleep(1)
                results = f"MCM Verification Checks/{mcm}/{stage}-Checks/{hostname}-{mcm}-{stage}-Checks.txt"
                with open(results, "a") as fp:
                    fp.write(output)
                print(
                    f"Verification commands were successfully captured on {hostname}!"
                )

Thanks for the help!