Serial consoles#

On a live boot the installer takes over the first video console and nothing else. A serial console keeps a normal login prompt, and its banner tells you what to do about it: log in as vyos / vyos and run sudo wheelhouse-install. It is the same walk-through, drawn by dialog in 80 columns, which is what every screen and banner in the installer is sized for.

Running the installer#

sudo wheelhouse-install

The waiting screen comes first — VyOS loading its configuration and the agent starting, which takes a couple of minutes on a slow box — and then the same welcome menu a video console shows. From there the screens are identical: Every installer question.

If you started the installer before the agent was ready you will see a plain counter rather than a dialog box:

waiting for the agent (35s)

That is the same wait, printed rather than drawn.

The installer takes the first video console only#

A systemd generator makes getty@tty1.service run the installer on a live boot. It touches tty1 and nothing else, so serial-getty@ttyS0.service and every other console keep their login prompt. A serial console is often a lights-out management port that something else is already watching, and the installer leaves it alone.

The banner on a serial line#

The console banner is written to /etc/issue and shown above every login prompt, on every console. On a live image it ends with:

  Console:   vyos / vyos on the live image; the installer sets yours
  Install:   on the first console; elsewhere run: sudo wheelhouse-install

The banner is rewritten every 20 seconds, and when the text changes it restarts the login prompts nobody is sitting at — including serial-getty@* units — so the new text is drawn immediately. Two consoles are left alone: one with someone logged in, and tty1 while the installer holds its lock file.

The installed system keeps the console you installed from#

The installer reads the kernel command line. If it finds console=ttyS it tells VyOS' image installer to make the serial console the default on the installed system, so a headless box stays reachable the way you installed it. On a video boot it answers the same question with the keyboard console instead.

The answer goes to the base installer's What console should be used by default? prompt, so it is the base system's own setting.

Getting a shell without a console at all#

There is none by default. SSH is off on a freshly installed router: neither the image's default configuration nor the installer writes service ssh. On a headless machine there are two ways to arrange access before you need it:

• Put a public key on the console account during the install. The unattended installer does this from a seed, so the box is reachable the moment it boots — Installing without a keyboard. You still have to turn SSH on; the keys are placed, the service is not.
• Give a management source at install time on a box with a WAN and no LAN, so the web UI is reachable from a prefix you name — Boxes with one port.

See also#

• Every installer question — the screens, once you have started it.
• Installing without a keyboard — no console at all.
• Boxes with one port — the other headless-adjacent case.
• First sign-in — what the banner says once the box is installed.
• Working from the console — the console on an installed router.
• Turn SSH on — the remote shell that is off by default.
• Locked out — when the console is the only way in.