fix: #12883, activitypub probe timeout

- Added setting to disable probe completely
- Added setting to configure timeout
- Updated probe logic so that if probe times out, it retries in the background with 60s timeout for caching purposes

install/data/defaults.json

@@ -193,6 +193,8 @@
     "disableCustomUserSkins": 0,
     "activitypubEnabled": 1,
     "activitypubAllowLoopback": 0,
+    "activitypubProbe": 1,
+    "activitypubProbeTimeout": 500,
     "activitypubContentPruneDays": 30,
     "activitypubUserPruneDays": 7,
     "activitypubFilter": 0

public/language/en-GB/admin/settings/activitypub.json

@@ -12,6 +12,12 @@
 	"allowLoopback": "Allow loopback processing",
 	"allowLoopback-help": "Useful for debugging purposes only. You should probably leave this disabled.",
 
+	"probe": "Open in App",
+	"probe-enabled": "Try to open ActivityPub-enabled resources in NodeBB",
+	"probe-enabled-help": "If enabled, NodeBB will check every external link for an ActivityPub equivalent, and load it in NodeBB instead.",
+	"probe-timeout": "Lookup Timeout (milliseconds)",
+	"probe-timeout-help": "(Default: 500) If the lookup query does not receive a response within the set timeframe, will send the user to the link directly instead. Adjust this number higher if sites are responding slowly and you wish to give extra time.",
+
 	"server-filtering": "Filtering",
 	"count": "This NodeBB is currently aware of <strong>%1</strong> server(s)",
 	"server.filter-help": "Specify servers you would like to bar from federating with your NodeBB. Alternatively, you may opt to selectively <em>allow</em> federation with specific servers, instead. Both options are supported, although they are mutually exclusive.",

public/src/ajaxify.js

@@ -609,7 +609,7 @@ $(document).ready(function () {
 								ajaxify.go('outgoing?url=' + encodeURIComponent(href));
 								e.preventDefault();
 							}
-						} else {
+						} else if (config.activitypub.probe) {
 							ajaxify.go(`ap?resource=${encodeURIComponent(this.href)}`);
 							e.preventDefault();
 						}

src/activitypub/index.js

@@ -490,8 +490,10 @@ ActivityPub.probe = async ({ uid, url }) => {
 	}
 
 	// Opportunistic HEAD
-	const { response } = await request.head(url);
-	try {
+	async function checkHeader(timeout) {
+		const { response } = await request.head(url, {
+			timeout,
+		});
 		const { headers } = response;
 		if (headers && headers.link) {
 			let parts = headers.link.split(';');
@@ -509,8 +511,19 @@ ActivityPub.probe = async ({ uid, url }) => {
 				return true;
 			}
 		}
+
+		return false;
+	}
+	try {
+		await checkHeader(meta.config.activitypubProbeTimeout || 500);
 	} catch (e) {
-		// ...
+		if (e.name === 'TimeoutError') {
+			// Return early but retry for caching purposes
+			checkHeader(1000 * 60).then((result) => {
+				probeCache.set(url, result);
+			});
+			return false;
+		}
 	}
 
 	probeCache.set(url, false);

src/controllers/api.js

@@ -97,6 +97,9 @@ apiController.loadConfig = async function (req) {
 			styles: fontawesome_styles,
 			version: fontawesome_version,
 		},
+		activitypub: {
+			probe: meta.config.activitypubProbe,
+		},
 	};
 
 	let settings = config;

src/views/admin/settings/activitypub.tpl

@@ -24,6 +24,26 @@
 		</div>
 	</div>
 
+	<div class="row settings m-0">
+		<div class="col-sm-2 col-12 settings-header">[[admin/settings/activitypub:probe]]</div>
+		<div class="col-sm-10 col-12">
+			<form>
+				<div class="form-check form-switch mb-3">
+					<input class="form-check-input" type="checkbox" data-field="activitypubProbe">
+					<label class="form-check-label">[[admin/settings/activitypub:probe-enabled]]</label>
+					<p class="form-text">[[admin/settings/activitypub:probe-enabled-help]]</p>
+				</div>
+				<div class="mb-3">
+					<label class="form-label" for="activitypubProbeTimeout">[[admin/settings/activitypub:probe-timeout]]</label>
+					<input type="number" id="activitypubProbeTimeout" name="activitypubProbeTimeout" data-field="activitypubProbeTimeout" title="[[admin/settings/activitypub:probe-timeout]]" class="form-control" />
+					<div class="form-text">
+						[[admin/settings/activitypub:probe-timeout-help]]
+					</div>
+				</div>
+			</form>
+		</div>
+	</div>
+
 	<div class="row settings m-0">
 		<div class="col-sm-2 col-12 settings-header">[[admin/settings/activitypub:pruning]]</div>
 		<div class="col-sm-10 col-12">