Implement comprehensive monitoring improvements

- Add full email notifications with lettre and Stockholm timezone
- Add status persistence to prevent notification spam on restart
- Change nginx monitoring to check backend proxy_pass URLs instead of frontend domains
- Increase nginx site timeout to 10 seconds for backend health checks
- Fix cache intervals: disk (5min), backup (10min), systemd (30s), cpu/memory (5s)
- Remove rate limiting for immediate notifications on all status changes
- Store metric status in /var/lib/cm-dashboard/last-status.json

agent/src/collectors/systemd.rs

@@ -595,8 +595,8 @@ impl SystemdCollector {
 
         // Create HTTP client with timeouts (similar to legacy implementation)
         let client = reqwest::blocking::Client::builder()
-            .timeout(Duration::from_secs(5))
-            .connect_timeout(Duration::from_secs(2))
+            .timeout(Duration::from_secs(10))
+            .connect_timeout(Duration::from_secs(10))
             .redirect(reqwest::redirect::Policy::limited(10))
             .build()?;
 
@@ -739,12 +739,9 @@ impl SystemdCollector {
         while i < lines.len() {
             let line = lines[i].trim();
             if line.starts_with("server") && line.contains("{") {
-                debug!("Found server block at line {}", i);
-                if let Some(server_name) = self.parse_server_block(&lines, &mut i) {
-                    debug!("Extracted server name: {}", server_name);
-                    let url = format!("https://{}", server_name);
-                    // Use the full domain as the site name for clarity
-                    sites.push((server_name.clone(), url));
+                if let Some(proxy_url) = self.parse_server_block(&lines, &mut i) {
+                    let site_name = proxy_url.replace("http://", "").replace("https://", "");
+                    sites.push((site_name, proxy_url));
                 }
             }
             i += 1;
@@ -758,6 +755,7 @@ impl SystemdCollector {
     fn parse_server_block(&self, lines: &[&str], start_index: &mut usize) -> Option<String> {
         use tracing::debug;
         let mut server_names = Vec::new();
+        let mut proxy_pass_url = None;
         let mut has_redirect = false;
         let mut i = *start_index + 1;
         let mut brace_count = 1;
@@ -787,6 +785,17 @@ impl SystemdCollector {
                 }
             }
 
+            // Extract proxy_pass URL (backend IP:port)
+            if trimmed.starts_with("proxy_pass") {
+                if let Some(url_part) = trimmed.strip_prefix("proxy_pass") {
+                    let url_clean = url_part.trim().trim_end_matches(';');
+                    if !url_clean.is_empty() {
+                        proxy_pass_url = Some(url_clean.to_string());
+                        debug!("Found proxy_pass in block: {}", url_clean);
+                    }
+                }
+            }
+
             // Check for redirects (skip redirect-only servers)
             if trimmed.contains("return") && (trimmed.contains("301") || trimmed.contains("302")) {
                 has_redirect = true;
@@ -797,11 +806,12 @@ impl SystemdCollector {
 
         *start_index = i - 1;
 
-        // Only return hostnames that are not redirects and have actual content
-        if !server_names.is_empty() && !has_redirect {
-            Some(server_names[0].clone())
-        } else {
-            None
+        if let Some(proxy_url) = proxy_pass_url {
+            if !has_redirect {
+                return Some(proxy_url);
+            }
         }
+
+        None
     }
 }