spawny

Spawny presents a daemon which can prompt for logins on ttys. It is splitted up into multiple subsystems

Installation

To build the software you can just create a bin directory like build,

mkdir build

After that you can build and install the software by doing:

cd build

meson ..

ninja all

sudo ninja install

To get the sp-daemon to run on your system you need to enable and start the sp-daemon.socket unit by calling: systemctl enable sp-daemon.socket and systemctl start sp-daemon.socket

If you want to automatically get a greeter on system start you need to enable the sp-greeter-start unit by calling:

systemctl start sp-greeter-start.socket

sp-daemon

The daemon opens a socket and listens there for requests. If someone requests a new session or the displaying of a greeter, the following steps are done:

• A new process is forked.
• The new process calls setsid() so its a new session
• A new tty console is opened and added, the process is attached as leader
• The user is logged in using pam
• Waiting for its new session to be activated
• Starts up the greeter or the session-template which was applied

The daemon also loads its session-templates from /usr/share/xsessions, /usr/share/wayland-sessions and offers a tty template which just starts the users bash

A different greeter from the sp-fallback-greeter can be configured in the config file.

sp-fallback-greeter

This is a greeter that just uses the command line interface. It is used as fallback for the case a configured greeter crashes 3 times, or cannot be started / found.

The fallback greeter looks like that:

sp-greeter-set

Will set the passed greeter as the one that will get started after a sp-greeter-start call.

sp-greeter-start

Requests the daemon to start a greeter on the same seat where this process is in.

libsp_client

A little shared object library that abstracts the communication with the deamon. It can be used by other greeters, it is also used by sp-greeter-start and sp-fallback-greeter.

sp-protocol

The whole repository needs a few protobuf files to work correctly. This little static library brings in the generated files from the protobuf files and a few other functions that are used by the sp-daemon and the libsp_client.

sp-user-db(-utils)

There is one problem with the /etc/passwd file on linux systems. It is very static and you cannot add any additional data to them. For something like spawny and a graphical greeter it could be very usefull to have a user configured icon or prefered template to use. Those are the packages that are implementing that