Build it, step by step

# Download the VyOS rolling ISO used in this lesson and extract its kernel and initrd.
mkdir -p vyos && cd vyos
curl -LO https://github.com/vyos/vyos-nightly-build/releases/download/2026.10.16-0024-rolling/vyos-2026.10.16-0024-rolling-generic-amd64.iso
mv vyos-*-amd64.iso vyos.iso
tar -xf vyos.iso live/vmlinuz live/initrd.img   # bsdtar (macOS) reads ISOs; on Linux use 7z or bsdtar
mv live/vmlinuz live/initrd.img . && rmdir live

bgpd=yes
ospfd=no
ospf6d=no
ripd=no
ripngd=no
isisd=no
pimd=no
ldpd=no
nhrpd=no
eigrpd=no
babeld=no
sharpd=no
pbrd=no
bfdd=no
fabricd=no
vrrpd=no
pathd=no
staticd=yes
vtysh_enable=yes
zebra_options="  -A 127.0.0.1 -s 90000000"
bgpd_options="   -A 127.0.0.1"
staticd_options="-A 127.0.0.1"

service integrated-vtysh-config

#!/usr/bin/env python3
"""Drive the VyOS VM's serial console (QEMU unix socket) and print a clean transcript.

  vyos-console.py wait [secs]            wait for the login prompt
  vyos-console.py login                  log in as vyos/vyos
  vyos-console.py op 'show version' ...  run operational commands
  vyos-console.py conf 'set ...' ...     configure, run set/delete lines, commit, exit
  vyos-console.py capture SECS 'cmd'     run a command that needs Ctrl-C (monitor traffic), stop after SECS
"""
import os, re, socket, sys, time

SOCK = os.environ.get('VYOS_CONSOLE', '/run/console.sock')
ANSI = re.compile(r'\x1b\[[0-9;?]*[ -/]*[@-~]|\x1b[=>()][0-9A-Za-z]?|\r|\x07|\x08')
OP_PROMPT = r'vyos@[\w-]+:~\$ $'
CONF_PROMPT = r'vyos@[\w-]+# $'

def connect():
    s = socket.socket(socket.AF_UNIX)
    s.connect(SOCK)
    s.settimeout(0.3)
    return s

def read_until(s, pattern, timeout):
    buf, end = '', time.time() + timeout
    while time.time() < end:
        try:
            data = s.recv(65536)
        except socket.timeout:
            data = b''
        if data:
            buf += data.decode('utf-8', 'replace')
            if re.search(pattern, ANSI.sub('', buf)):
                return ANSI.sub('', buf), True
    return ANSI.sub('', buf), False

def send(s, line):
    s.sendall(line.encode() + b'\n')

def run(s, cmd, prompt, timeout=300):
    send(s, cmd)
    out, ok = read_until(s, prompt, timeout)
    if not ok:
        sys.stderr.write(f'!! timeout waiting for prompt after: {cmd}\n')
    return out

def main():
    mode, args = sys.argv[1], sys.argv[2:]
    s = connect()
    if mode == 'wait':
        end = time.time() + float(args[0] if args else 900)
        while time.time() < end:
            send(s, '')
            out, ok = read_until(s, r'login: $|\$ $|# $', 10)
            if ok:
                print('ready:', out.strip().splitlines()[-1])
                return
        sys.exit('timeout waiting for login prompt')
    if mode == 'login':
        send(s, '')
        out, _ = read_until(s, r'login: $|\$ $', 30)
        if out.rstrip().endswith('$'):
            print('already logged in'); return
        send(s, 'vyos'); read_until(s, r'Password: $', 60)
        send(s, 'vyos'); out, ok = read_until(s, OP_PROMPT, 300)
        print('logged in' if ok else 'login failed:\n' + out[-500:])
        for c in ('set terminal length 0', 'set terminal width 200'):
            run(s, c, OP_PROMPT, 60)
        return
    if mode == 'op':
        send(s, ''); read_until(s, OP_PROMPT, 30)
        for cmd in args:
            sys.stdout.write(run(s, cmd, OP_PROMPT))
        print()
        return
    if mode == 'conf':
        send(s, ''); read_until(s, OP_PROMPT, 30)
        transcript = run(s, 'configure', CONF_PROMPT, 120)
        for cmd in args:
            transcript += run(s, cmd, CONF_PROMPT, 120)
        transcript += run(s, 'commit', CONF_PROMPT, 900)
        transcript += run(s, 'exit', OP_PROMPT, 120)
        sys.stdout.write(transcript)
        print()
        return
    if mode == 'capture':
        secs, cmd = float(args[0]), args[1]
        send(s, ''); read_until(s, OP_PROMPT, 30)
        send(s, cmd)
        out, _ = read_until(s, r'(?!)', secs)  # collect output for SECS
        s.sendall(b'\x03')
        rest, _ = read_until(s, OP_PROMPT, 60)
        sys.stdout.write(out + rest)
        print()
        return
    sys.exit(__doc__)

main()