leanderk/spawny repository overview

⁠spawny

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

⁠Installation

The repository is using a external .ini parser that can get pulled in by running:

git update --init --recursive

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

cmake ..

make all

sudo make install

⁠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 form /usr/xsessions /user/wayland-session 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-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. there are 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