From eb6329e6f74105a10446b9eb546da8faf00464d5 Mon Sep 17 00:00:00 2001
From: "D. Berge" <dberge@aaltronav.eu>
Date: Tue, 6 Oct 2020 19:44:07 +0200
Subject: [PATCH] Catch DB connection errors.

If we can't connect straight away (either first time
or after a disconnection), keep retrying until we
manage.
---
 lib/www/server/ws/db.js | 38 +++++++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/lib/www/server/ws/db.js b/lib/www/server/ws/db.js
index 669ea99..c9a9a17 100644
--- a/lib/www/server/ws/db.js
+++ b/lib/www/server/ws/db.js
@@ -27,29 +27,41 @@ function reconnect () {
 
 async function listen (addChannels, callback) {
 	if (!client) {
-		client = await pool.connect();
+		try {
+			client = await pool.connect();
+		} catch (err) {
+			console.error("Error connecting to DB", err);
+			console.log("Will try again in 15 seconds");
+			setImmediate(() => client = null);
+			setTimeout(() => {
+				listen(addChannels, callback);
+			}, 15000);
+			return;
+		}
 		client.on('notification', notify);
-		console.log("Client connected");
+		console.log("Client connected", Object.keys(channels));
 		client.on('error', (err) => console.error("Events client error: ", err));
 		client.on('end', () => {
-			console.warning("Events client disconnected. Will attempt to reconnect in five seconds");
+			console.warn("Events client disconnected. Will attempt to reconnect in five seconds");
 			setImmediate(() => client = null);
 			setTimeout(reconnect, 5000);
 		});
 	}
 
-	if (addChannels && !Array.isArray(addChannels)) {
-		addChannels = [addChannels];
-	}
-
-	for (const channel of addChannels) {
-		if (!(channel in channels)) {
-			await client.query("LISTEN "+channel);
-			channels[channel] = [];
-			console.log("Listening to ", channel);
+	if (addChannels) {
+		if (!Array.isArray(addChannels)) {
+			addChannels = [addChannels];
 		}
 
-		channels[channel].push(callback);
+		for (const channel of addChannels) {
+			if (!(channel in channels)) {
+				await client.query("LISTEN "+channel);
+				channels[channel] = [];
+				console.log("Listening to ", channel);
+			}
+
+			channels[channel].push(callback);
+		}
 	}
 }