From b33f1ad1b3ef3654973f2686b32c6bf19f4b0b73 Mon Sep 17 00:00:00 2001
From: postscriptum <postscriptum@gemlog>
Date: Thu, 3 Jul 2025 16:09:45 +0300
Subject: [PATCH] add systemd configuration example

---
 README.md | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/README.md b/README.md
index 716eb53..b94e9ba 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,53 @@ snac2nex -s /path/to/snac/storage -t /path/to/nex -u user1 -u user2
           Print version
 ```
 
+### Systemd
+
+To use `snac2nex` as the `systemd` service, install binary to the canonical system location:
+
+* `git clone https://codeberg.org/postscriptum/snac2nex.git && cd snac2nex`
+* `cargo build --release`
+* `sudo install target/release/snac2nex /usr/local/bin/snac2nex`
+  * tip: now you may want to clean the `snac2nex` sources folder to free up disk space
+
+Setup shared access permissions:
+
+1. `useradd -m snac2nex` - create new user with home dir (for log files)
+2. `usermod -aG snac snac2nex` - replace `snac` with the `systemd` group for your [Snac](https://codeberg.org/grunfink/snac2) server
+  * `chmod -R g+r /path/to/snac/storage` - give the group read permissions to Snac directories
+3. `usermod -aG nexy snac2nex` - replace `nexy` with the `systemd` group for your your Nex protocol server (e.g. [Nexy](https://github.com/YGGverse/nexy))
+  * `chmod -R g+rw /path/to/nex` - give the group read/write permissions to Nex directories
+
+Create new `systemd` configuration file `/etc/systemd/system/snac2nex.service`:
+``` snac2nex.service
+[Unit]
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=snac2nex
+Group=snac2nex
+# Uncomment if your Snac or Nex unit has ExecStartPre timeout option
+# ExecStartPre=/bin/sleep 15
+ExecStart=/usr/local/bin/snac2nex -s /path/to/snac/storage -t /path/to/nex -u user1 -u user2 -r 3600 -d
+StandardOutput=file:/home/snac2nex/debug.log
+StandardError=file:/home/snac2nex/error.log
+
+[Install]
+WantedBy=multi-user.target
+```
+* replace `ExecStart` arguments with your values, where:
+  * `-s` - Snac `storage` location
+  * `-u` - Snac `user`(s) to sync
+  * `-t` - Nex server `target` location for public files
+  * `-r` - is `rotate` every hour (`3600` seconds) to apply Snac instance updates (instead of export once)
+  * `-d` - enable `daemon` mode, which disables some debug output, to prevent extra write operations
+  * optionally, include `-a` (`attachment`) as `c` (`copy`) | `h` (`hard` link) | `s` (`soft` link)
+* `systemctl daemon-reload` - apply new `systemd` configuration
+* `systemctl enable snac2nex` - auto-start `snac2nex` sync on system boot
+* `systemctl start snac2nex` - start `snac2nex` sync now
+
 ## See also
 
 * [Nexy](https://github.com/YGGverse/nexy) - Server for the Nex protocol, written in Rust