Calibre-server systemd socket unit example

[davidreads]

The calibre documentation mentions that it supports socket activation. Does anyone have a working socket unit and service unit pair that will start the server on first connection then stop the server after some timeout? Thanks in advance.

David

[davidreads]

Answering my own question for future readers.

I created the following systemd unit files:

calibre-server@.socket:

[Unit]
Description=Calibre Server socket

[Socket]
ListenStream=33154

[Install]
WantedBy=sockets.target

calibre-server@.service

[Unit]
Description=Calibre content server
After=network.target

[Service]
Type=simple
User=%i
Group=%i
ExecStart=/usr/bin/calibre-server --enable-allow-socket-preallocation "/home/%i/Media/Books/Calibre Library"
RuntimeMaxSec=300
Restart=no

[Install]
WantedBy=multi-user.target

I can then start them with:

systemctl start calibre-server@user1.socket

This will start the socket service for user1 to listen for connections. On connection, it will run calibre-server as user1 and serve the books out of that users's calibre library. The instance of calibre-server will stop after 5 minutes to minimize use of system resources but will start again on the next connection.

I can also add another socket unit named calibre-server@user2.socket with a different ListenStream to serve user2's library on a different port.