Self-hosting a Cooklang Server via systemd

[Unit]
# Describe your unit. This is displayed in various system utilities for human administrators to understand what they're looking at.
Description="cooklang web server"
# The After parameter can be repeated and tells systemd that this unit file MUST NOT be started until the named resources are successfully made available.
# The syslog target guarantees that logs emitted by the cooklang server can be collected.
After=syslog.target
# The network target is available when the OS's network stack comes up. Being a web server, it doesn't really make sense to start until we can talk to other computers.
After=network.target

[Service]
# This throttles how quickly the service will be restarted. systemd will only attempt to restart the cooklang server once every 2 seconds. For applications that induce heavy load on the host machine during startup, this can be critical for preventing death spirals or otherwise degrading the performance of other services.
RestartSec=2s
# This is probably the most complex parameter in the whole file. For most processes, simple will do. I recommend reading through the documentation ( https://www.freedesktop.org/software/systemd/man/latest/systemd.service.html#Type= ) for more info.
Type=simple
# Tells systemd what user the process should be started as. Remember, anything that communicates with the outside world should be run as a standalone user with minimal priveleges; if the process is compromised, this limits the scope of damage malicious actors can cause.
User=cook
# Similar to the user parameter. UNIX groups allow different users to share access to a limited set of resources.
Group=cook
# WorkingDirectory effectively tells systemd to cd into the specified directory before executing the process.
WorkingDirectory=/home/cook/recipes/
# Here we tell systemd how to actually start the supervised process.
ExecStart=cook server
# The Restart parameter tells systemd how to handle restarting the process when it fails or is asked to restart by an operator. always means "Ignore exit codes and other signals and restart the process when asked, no matter what happens". For details on the other options, see https://www.freedesktop.org/software/systemd/man/latest/systemd.service.html#Restart=
Restart=always

[Install]
# WantedBy is part of systemd's dependency-chain configuration. multi-user.target is marked as available when the kernel/OS pass from single-user mode to multi-user mode, effectively meaning that the system is ready to start doing stuff other than bootstrapping the hardware and kernel. In short, "when the machine boots up, start me".
WantedBy=multi-user.target

cook.ndumas.com {
    encode gzip
    reverse_proxy localhost:9080
}

[Unit]
Description=cooklang server restarter
After=network.target
# The next two parameters work in tandem to prevent the service file from being triggered too many times, whatever that may mean for a given process. During each span of 10 seconds, systemd will only attempt to restart the process 5 times. Much like Restart in cooklang.service, this is to prevent death-spiraling and degradation of other processes on the host.
StartLimitIntervalSec=10
StartLimitBurst=5

[Service]
# oneshot is similar to simple but it considers the unit "up"/available after the process exits. Use this when the process you're running is not meant to persist.
Type=oneshot
ExecStart=/usr/bin/systemctl restart cooklang.service

[Install]
WantedBy=multi-user.target

[Unit]
Description="Monitor /home/cook/recipes for changes"

[Path]
# This tells systemd which service to trigger when the configured file events are detected. Here, we're telling it "Trigger cooklang-watcher.service when you detect changes to /home/cook/recipes"
Unit=cooklang-watcher.service
# PathModified is one of several subtle variations that tell systemd what directory/file to watch and what type of events to care about. PathModified catches more events than PathChanged which is important because I'll frequently be editing these files interactively in vim as opposed to say, a CI/CD system which will do big batches of simple writes.
# For more info, see the docs https://www.freedesktop.org/software/systemd/man/latest/systemd.path.html#PathExists=
PathModified=/home/cook/recipes

[Install]
WantedBy=multi-user.target