feat(core): Add config option for the url preview user agent

conduwuit-example.toml

@@ -1474,6 +1474,12 @@
 #
 #url_preview_check_root_domain = false
 
+# User agent that is used specifically when downloading url previews.
+#
+# example: "continuwuity (bot; +https://forgejo.ellis.link/continuwuation/continuwuity)"
+#
+#url_preview_user_agent = "continuwuity/$VERSION ($VERSION_TAG)"
+
 # List of forbidden room aliases and room IDs as strings of regex
 # patterns.
 #

src/core/config/mod.rs

@@ -1696,6 +1696,13 @@ pub struct Config {
 	#[serde(default)]
 	pub url_preview_check_root_domain: bool,
 
+	/// User agent that is used specifically when downloading url previews.
+	///
+	/// example: "continuwuity (bot; +https://forgejo.ellis.link/continuwuation/continuwuity)"
+	///
+	/// default: "continuwuity/$VERSION ($VERSION_TAG)"
+	pub url_preview_user_agent: Option<String>,
+
 	/// List of forbidden room aliases and room IDs as strings of regex
 	/// patterns.
 	///

src/service/client/mod.rs

@@ -36,6 +36,11 @@ impl crate::Service for Service {
 			.clone()
 			.and_then(Either::right);
 
+		let url_preview_user_agent = config
+			.url_preview_user_agent
+			.clone()
+			.unwrap_or_else(|| conduwuit::version::user_agent().to_string());
+
 		Ok(Arc::new(Self {
 			default: base(config)?
 				.dns_resolver(resolver.resolver.clone())
@@ -49,6 +54,7 @@ impl crate::Service for Service {
 				.dns_resolver(resolver.resolver.clone())
 				.timeout(Duration::from_secs(config.url_preview_timeout))
 				.redirect(redirect::Policy::limited(3))
+				.user_agent(url_preview_user_agent)
 				.build()?,
 
 			extern_media: base(config)?