feat: add Prometheus and Grafana configurations and document Alpine Docker setup

SETUP.md

@@ -249,8 +249,38 @@ For testing deployments on a local network server without setting up a full prod
 
 #### Test Environment Prerequisites
 
-- A remote server running Docker at IP `192.168.88.40`.
-- Docker TCP socket enabled and listening on port `2375` on the remote server (ensure this port is secured/firewalled to trusted local IPs only).
+- A remote server running Docker at IP `192.168.88.40` (running Alpine Linux).
+- Docker TCP socket enabled and listening on port `2375` on the remote server.
+
+##### Enabling Docker TCP Socket on Alpine Linux
+
+To allow the Gitea Actions runner (or your local machine) to deploy to the remote Alpine host, you must configure the Docker daemon to listen on the TCP socket:
+
+1. Edit `/etc/conf.d/docker` on the Alpine host:
+
+   ```bash
+   vi /etc/conf.d/docker
+   ```
+
+2. Update the `DOCKER_OPTS` line to include both the unix socket and the TCP socket:
+
+   ```bash
+   DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375"
+   ```
+
+3. Restart the Docker service:
+
+   ```bash
+   rc-service docker restart
+   ```
+
+4. Verify that Docker is listening on port `2375`:
+
+   ```bash
+   netstat -tlnp | grep 2375
+   ```
+
+5. Ensure any firewall (like `awall` or `iptables`) on the Alpine host allows incoming traffic on port `2375` from your local network subnet (e.g., `192.168.88.0/24`).
 
 #### Deployment Steps