➕ Add "last seen" to server list

Cargo.toml

@@ -13,6 +13,7 @@ license = "AGPL-3.0"
 aho-corasick = "0.7.14"
 base64 = "0.12.3"
 blake3 = "0.3.7"
+chrono = "0.4.19"
 ctrlc = { version = "3.1.7", features = [ "termination" ] }
 dashmap = "3.11.10"
 futures = "0.3.7"

handlebars/relay/relay_server_list.html

@@ -6,12 +6,25 @@
 	body {
 		font-family: sans-serif;
 	}
-	.entry {
-		display: inline-block;
-		padding: 20px;
-		min-width: 50%;
+	td {
+		padding: 0px;
 	}
-	.entry_list div:nth-child(odd) {
+	td > * {
+		padding: 20px;
+		display: block;
+	}
+	.entry {
+		
+	}
+	.grey {
+		color: #888;
+		text-align: right;
+	}
+	.entry_list {
+		width: 100%;
+		border-collapse: collapse;
+	}
+	tbody tr:nth-child(odd) {
 		background-color: #ddd;
 	}
 </style>
@@ -21,19 +34,28 @@
 
 <h1>Server list</h1>
 
-<div class="entry_list">
-
 {{#if servers}}
-	{{#each servers}}
-		<div>
-		<a class="entry" href="{{this.path}}/files/">{{this.name}}</a>
-		</div>
-	{{/each}}
-{{else}}
-	(No servers are running)
-{{/if}}
+	<table class="entry_list">
+	<thead>
+	<tr>
+	<th>Name</th>
+	<th>Last seen</th>
+	</tr>
+	</thead>
+	<tbody>
 	
-</div>
+	{{#each servers}}
+		<tr>
+		<td><a class="entry" href="{{this.path}}/files/">{{this.name}}</a></td>
+		<td><span class="grey">{{this.last_seen}}</span></td>
+		</tr>
+	{{/each}}
+	
+	</tbody>
+	</table>
+{{else}}
+	(No servers have reported since this relay started)
+{{/if}}
 
 </body>
 </html>

handlebars/server/file_server_dir.html

@@ -6,19 +6,25 @@
 	body {
 		font-family: sans-serif;
 	}
-	.entry {
-		display: inline-block;
+	td {
+		padding: 0;
+	}
+	td > * {
 		padding: 10px;
-		width: 100%;
+		display: block;
+	}
+	.entry {
 		text-decoration: none;
 	}
 	.grey {
 		color: #888;
+		text-align: right;
 	}
 	.entry_list {
 		width: 100%;
+		border-collapse: collapse;
 	}
-	.entry_list tr:nth-child(even) {
+	tbody tr:nth-child(odd) {
 		background-color: #ddd;
 	}
 </style>

src/relay/mod.rs

@@ -127,12 +127,32 @@ impl From <&ConfigFile> for Config {
 	}
 }
 
+use chrono::{ 
+	DateTime,
+	SecondsFormat,
+	Utc 
+};
+
+#[derive (Clone)]
+pub struct ServerStatus {
+	last_seen: DateTime <Utc>,
+}
+
+impl Default for ServerStatus {
+	fn default () -> Self {
+		Self {
+			last_seen: Utc::now (),
+		}
+	}
+}
+
 pub struct RelayState {
 	config: Config,
 	handlebars: Arc <Handlebars <'static>>,
 	
 	// Key: Server ID
 	request_rendezvous: Mutex <HashMap <String, RequestRendezvous>>,
+	server_status: Mutex <HashMap <String, ServerStatus>>,
 	
 	// Key: Request ID
 	response_rendezvous: RwLock <DashMap <String, ResponseRendezvous>>,
@@ -149,6 +169,7 @@ impl From <&ConfigFile> for RelayState {
 			config: Config::from (config_file),
 			handlebars: Arc::new (load_templates (&PathBuf::new ()).unwrap ()),
 			request_rendezvous: Default::default (),
+			server_status: Default::default (),
 			response_rendezvous: Default::default (),
 			shutdown_watch_tx,
 			shutdown_watch_rx,
@@ -205,6 +226,16 @@ async fn handle_http_listen (
 		return trip_error;
 	}
 	
+	// End of early returns
+	
+	{
+		let mut server_status = state.server_status.lock ().await;
+		
+		let mut status = server_status.entry (watcher_code.clone ()).or_insert_with (Default::default);
+		
+		status.last_seen = Utc::now ();
+	}
+	
 	use RequestRendezvous::*;
 	
 	let (tx, rx) = oneshot::channel ();
@@ -454,6 +485,99 @@ async fn handle_http_request (
 	}
 }
 
+#[derive (Debug, PartialEq)]
+enum LastSeen {
+	Negative,
+	Connected,
+	Description (String),
+}
+
+// Mnemonic is "now - last_seen"
+
+fn pretty_print_last_seen (
+	now: DateTime <Utc>,
+	last_seen: DateTime <Utc>
+) -> LastSeen
+{
+	use LastSeen::*;
+	
+	let dur = now.signed_duration_since (last_seen);
+	
+	if dur < chrono::Duration::zero () {
+		return Negative;
+	}
+	
+	if dur.num_minutes () < 1 {
+		return Connected;
+	}
+	
+	if dur.num_hours () < 1 {
+		return Description (format! ("{} m ago", dur.num_minutes ()));
+	}
+	
+	if dur.num_days () < 1 {
+		return Description (format! ("{} h ago", dur.num_hours ()));
+	}
+	
+	Description (last_seen.to_rfc3339_opts (SecondsFormat::Secs, true))
+}
+
+
+async fn handle_server_list (
+	state: Arc <RelayState>
+) -> Response <Body>
+{
+	use std::borrow::Cow;
+	
+	#[derive (Serialize)]
+	struct ServerEntry <'a> {
+		path: String,
+		name: String,
+		last_seen: Cow <'a, str>,
+	}
+	
+	#[derive (Serialize)]
+	struct ServerListPage <'a> {
+		servers: Vec <ServerEntry <'a>>,
+	}
+	
+	let servers = {
+		let guard = state.server_status.lock ().await;
+		(*guard).clone ()
+	};
+	
+	let now = Utc::now ();
+	
+	let mut servers: Vec <_> = servers.into_iter ()
+	.map (|(name, server)| {
+		let display_name = percent_encoding::percent_decode_str (&name).decode_utf8 ().unwrap_or_else (|_| "Server name isn't UTF-8".into ()).to_string ();
+		
+		use LastSeen::*;
+		
+		let last_seen = match pretty_print_last_seen (now, server.last_seen) {
+			Negative => "Error (negative time)".into (),
+			Connected => "Connected".into (),
+			Description (s) => s.into (),
+		};
+		
+		ServerEntry {
+			name: display_name,
+			path: name,
+			last_seen: last_seen,
+		}
+	})
+	.collect ();
+	
+	servers.sort_by (|a, b| a.name.cmp (&b.name));
+	
+	let page = ServerListPage {
+		servers,
+	};
+	
+	let s = state.handlebars.render ("relay_server_list", &page).unwrap ();
+	ok_reply (s)
+}
+
 #[instrument (level = "trace", skip (req, state))]
 async fn handle_all (req: Request <Body>, state: Arc <RelayState>) 
 -> Result <Response <Body>, Infallible>
@@ -487,35 +611,7 @@ async fn handle_all (req: Request <Body>, state: Arc <RelayState>)
 	}
 	else if let Some (rest) = prefix_match ("/frontend/servers/", path) {
 		if rest == "" {
-			use std::borrow::Cow;
-			
-			#[derive (Serialize)]
-			struct ServerEntry <'a> {
-				path: &'a str,
-				name: Cow <'a, str>,
-			}
-			
-			#[derive (Serialize)]
-			struct ServerListPage <'a> {
-				servers: Vec <ServerEntry <'a>>,
-			}
-			
-			let mut names = state.list_servers ().await;
-			names.sort ();
-			
-			//println! ("Found {} servers", names.len ());
-			
-			let page = ServerListPage {
-				servers: names.iter ()
-				.map (|name| ServerEntry {
-					name: percent_encoding::percent_decode_str (name).decode_utf8 ().unwrap_or_else (|_| "Server name isn't UTF-8".into ()),
-					path: &name,
-				})
-				.collect (),
-			};
-			
-			let s = state.handlebars.render ("relay_server_list", &page).unwrap ();
-			ok_reply (s)
+			handle_server_list (state).await
 		}
 		else if let Some (idx) = rest.find ('/') {
 			let listen_code = String::from (&rest [0..idx]);
@@ -635,5 +731,29 @@ pub async fn run_relay (
 
 #[cfg (test)]
 mod tests {
+	use super::*;
 	
+	#[test]
+	fn test_pretty_print_last_seen () {
+		use LastSeen::*;
+		
+		let last_seen = DateTime::parse_from_rfc3339 ("2019-05-29T00:00:00+00:00").unwrap ().with_timezone (&Utc);
+		
+		for (input, expected) in vec! [
+			("2019-05-28T23:59:59+00:00", Negative),
+			("2019-05-29T00:00:00+00:00", Connected),
+			("2019-05-29T00:00:59+00:00", Connected),
+			("2019-05-29T00:01:30+00:00", Description ("1 m ago".into ())),
+			("2019-05-29T00:59:30+00:00", Description ("59 m ago".into ())),
+			("2019-05-29T01:00:30+00:00", Description ("1 h ago".into ())),
+			("2019-05-29T10:00:00+00:00", Description ("10 h ago".into ())),
+			("2019-05-30T00:00:00+00:00", Description ("2019-05-29T00:00:00Z".into ())),
+			("2019-05-30T10:00:00+00:00", Description ("2019-05-29T00:00:00Z".into ())),
+			("2019-05-31T00:00:00+00:00", Description ("2019-05-29T00:00:00Z".into ())),
+		].into_iter () {
+			let now = DateTime::parse_from_rfc3339 (input).unwrap ().with_timezone (&Utc);
+			let actual = pretty_print_last_seen (now, last_seen);
+			assert_eq! (actual, expected);
+		}
+	}
 }

src/server/file_server.rs

@@ -686,19 +686,12 @@ mod tests {
 		path::{
 			Component, 
 			Path,
-			PathBuf
 		},
 	};
 	
 	use maplit::*;
 	use tokio::runtime::Runtime;
 	
-	use always_equal::test::AlwaysEqual;
-	
-	use crate::http_serde::{
-		StatusCode,
-	};
-	
 	#[test]
 	fn icons () {
 		let video = "🎞️";

todo.md

@@ -10,7 +10,6 @@
 - ETag cache based on mtime
 - Server-side hash?
 - Log / audit log?
-- Add "Last check-in time" to server list
 
 - Prevent directory traversal attacks in file_server.rs
 - Error handling