add readme

crates/crawler/README.md

@@ -0,0 +1,58 @@
+# rssto-crawler
+
+## Install
+
+``` bash
+git clone https://github.com/YGGverse/rssto.git
+cd rssto
+cargo build --release
+```
+
+## Launch
+
+``` bash
+rssto-crawler -c config/example.toml
+```
+> [!TIP]
+> * prepend `RUST_LOG=rssto_crawler=trace` to print worker details (supported [levels](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.LevelFilter.html))
+>     * or just `RUST_LOG=trace` to debug all components in use
+> * append `-u TIME` to run as the daemon with `TIME` interval update
+> * see `rssto-crawler --help` to print all available options
+
+### Systemd
+
+1. Install `rssto-crawler` by copy the binary compiled into the native system apps destination:
+    * Linux: `sudo install target/release/rssto-crawler /usr/local/bin/rssto-crawler`
+2. Create `systemd` configuration file at `/etc/systemd/system/rssto-crawler.service`:
+
+``` rssto-crawler.service
+[Unit]
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+
+User=rssto
+Group=rssto
+
+# Uncomment for debug
+# Environment="RUST_LOG=DEBUG"
+# Environment="NO_COLOR=1"
+
+ExecStart=/usr/local/bin/rssto-crawler -c /path/to/config.toml
+
+StandardOutput=file:///home/rssto/crawler-debug.log
+StandardError=file:///home/rssto/crawler-error.log
+
+[Install]
+WantedBy=multi-user.target
+```
+* example above requires new system user (`useradd -m rssto`)
+
+3. Run in priority:
+
+* `systemctl daemon-reload` - reload systemd configuration
+* `systemctl enable rssto-crawler` - enable new service
+* `systemctl start rssto-crawler` - start the process
+* `systemctl status rssto-crawler` - check process launched