Add documentation for distro packaging

README.md

@@ -171,6 +171,11 @@ The main design goals of letmein are:
 
 For more information about security and reporting vulnerabilities, please see the [security documentation](SECURITY.md) of letmein.
 
+
+# Distribution packaging
+
+If you want to package the software for distribution, please see the [distribution packaging hints](doc/DISTRO_PACKAGING.md).
+
 # License
 
 Copyright (c) 2024-2025 Michael Büsch <m@bues.ch>

doc/DISTRO_PACKAGING.md

@@ -0,0 +1,13 @@
+# Recommendations for distribution packaging
+
+If you want to package the software for distribution, a few adjustments/patches are recommended:
+
+- If you install default configuration files, you might want to adjust `[NFTABLES] exe = ...` to the absolute path of your `nft` binary. See [the configuration documentation](CONFIGURATION.md#exe) for more details.
+
+- You probably want to install the systemd units under `/lib/systemd/system/` or similar, instead of `/etc`.
+
+- The build environment variable `LETMEIN_CONF_PREFIX` sets the prefix for the configuration files.
+  In a plain `cargo build` this will default to `/` meaning that `/etc/letmein{,d}.conf` will be the place for the configuration files.
+  If you use the `build.sh` script, the prefix will be set to `/opt/letmein` instead
+
+- Adjust the install prefix from `/opt` to something else that makes more sense for your distribution.