Add RSS feeds (fix #57)

Cargo.toml

@@ -42,8 +42,10 @@ fastrand = "2.0.1"
 log = "0.4.20"
 pretty_env_logger = "0.5.0"
 dotenvy = "0.15.7"
+rss = "2.0.7"
 arc-swap = "1.7.1"
 
+
 [dev-dependencies]
 lipsum = "0.9.0"
 sealed_test = "1.0.0"

README.md

@@ -381,7 +381,8 @@ Assign a default value for each instance-specific setting by passing environment
 | `ROBOTS_DISABLE_INDEXING` | `["on", "off"]` | `off`                  | Disables indexing of the instance by search engines.                                                      |
 | `PUSHSHIFT_FRONTEND`      | String          | `undelete.pullpush.io` | Allows the server to set the Pushshift frontend to be used with "removed" links.                          |
 | `PORT`                    | Integer 0-65535 | `8080`                 | The **internal** port Redlib listens on.                                                                  |
-
+| `ENABLE_RSS`              | `["on", "off"]` | `off`                  | Enables RSS feed generation.                                                                              |
+| `FULL_URL`                | String          | (empty)                | Allows for proper URLs (for now, only needed by RSS)
 ## Default user settings
 
 Assign a default value for each user-modifiable setting by passing environment variables to Redlib in the format `REDLIB_DEFAULT_{Y}`. Replace `{Y}` with the setting name (see list below) in capital letters.

app.json

@@ -56,8 +56,8 @@
     "REDLIB_BANNER": {
       "required": false
     },
-    "REDLIB_ROBOTS_DISABLE_INDEXING":  {
-        "required": false
+    "REDLIB_ROBOTS_DISABLE_INDEXING": {
+      "required": false
     },
     "REDLIB_DEFAULT_SUBSCRIPTIONS": {
       "required": false
@@ -70,6 +70,12 @@
     },
     "REDLIB_PUSHSHIFT_FRONTEND": {
       "required": false
+    },
+    "REDLIB_ENABLE_RSS": {
+      "required": false
+    },
+    "REDLIB_FULL_URL": {
+      "required": false
     }
   }
 }

src/config.rs

@@ -103,6 +103,12 @@ pub struct Config {
 	#[serde(rename = "REDLIB_PUSHSHIFT_FRONTEND")]
 	#[serde(alias = "LIBREDDIT_PUSHSHIFT_FRONTEND")]
 	pub(crate) pushshift: Option<String>,
+
+	#[serde(rename = "REDLIB_ENABLE_RSS")]
+	pub(crate) enable_rss: Option<String>,
+
+	#[serde(rename = "REDLIB_FULL_URL")]
+	pub(crate) full_url: Option<String>,
 }
 
 impl Config {
@@ -148,6 +154,8 @@ impl Config {
 			banner: parse("REDLIB_BANNER"),
 			robots_disable_indexing: parse("REDLIB_ROBOTS_DISABLE_INDEXING"),
 			pushshift: parse("REDLIB_PUSHSHIFT_FRONTEND"),
+			enable_rss: parse("REDLIB_ENABLE_RSS"),
+			full_url: parse("REDLIB_FULL_URL"),
 		}
 	}
 }
@@ -175,6 +183,8 @@ fn get_setting_from_config(name: &str, config: &Config) -> Option<String> {
 		"REDLIB_BANNER" => config.banner.clone(),
 		"REDLIB_ROBOTS_DISABLE_INDEXING" => config.robots_disable_indexing.clone(),
 		"REDLIB_PUSHSHIFT_FRONTEND" => config.pushshift.clone(),
+		"REDLIB_ENABLE_RSS" => config.enable_rss.clone(),
+		"REDLIB_FULL_URL" => config.full_url.clone(),
 		_ => None,
 	}
 }

src/instance_info.rs

@@ -126,6 +126,8 @@ impl InstanceInfo {
 				["Compile mode", &self.compile_mode],
 				["SFW only", &convert(&self.config.sfw_only)],
 				["Pushshift frontend", &convert(&self.config.pushshift)],
+				["RSS enabled", &convert(&self.config.enable_rss)],
+				["Full URL", &convert(&self.config.full_url)],
 				//TODO: fallback to crate::config::DEFAULT_PUSHSHIFT_FRONTEND
 			])
 			.with_header_row(["Settings"]),
@@ -165,6 +167,8 @@ impl InstanceInfo {
                 Compile mode: {}\n
 				SFW only: {:?}\n
 				Pushshift frontend: {:?}\n
+				RSS enabled: {:?}\n
+				Full URL: {:?}\n
                 Config:\n
                     Banner: {:?}\n
                     Hide awards: {:?}\n
@@ -189,6 +193,8 @@ impl InstanceInfo {
 					self.deploy_unix_ts,
 					self.compile_mode,
 					self.config.sfw_only,
+					self.config.enable_rss,
+					self.config.full_url,
 					self.config.pushshift,
 					self.config.banner,
 					self.config.default_hide_awards,

src/main.rs

@@ -254,6 +254,7 @@ async fn main() {
 	app.at("/u/:name/comments/:id/:title/:comment_id").get(|r| post::item(r).boxed());
 
 	app.at("/user/[deleted]").get(|req| error(req, "User has deleted their account").boxed());
+	app.at("/user/:name.rss").get(|r| user::rss(r).boxed());
 	app.at("/user/:name").get(|r| user::profile(r).boxed());
 	app.at("/user/:name/:listing").get(|r| user::profile(r).boxed());
 	app.at("/user/:name/comments/:id").get(|r| post::item(r).boxed());
@@ -265,6 +266,9 @@ async fn main() {
 	app.at("/settings/restore").get(|r| settings::restore(r).boxed());
 	app.at("/settings/update").get(|r| settings::update(r).boxed());
 
+	// RSS Subscriptions
+	app.at("/r/:sub.rss").get(|r| subreddit::rss(r).boxed());
+
 	// Subreddit services
 	app
 		.at("/r/:sub")

src/subreddit.rs

@@ -1,3 +1,4 @@
+use crate::{config, utils};
 // CRATES
 use crate::utils::{
 	catch_random, error, filter_posts, format_num, format_url, get_filters, nsfw_landing, param, redirect, rewrite_urls, setting, template, val, Post, Preferences, Subreddit,
@@ -459,6 +460,56 @@ async fn subreddit(sub: &str, quarantined: bool) -> Result<Subreddit, String> {
 	})
 }
 
+pub async fn rss(req: Request<Body>) -> Result<Response<Body>, String> {
+	if config::get_setting("REDLIB_ENABLE_RSS").is_none() {
+		return Ok(error(req, "RSS is disabled on this instance.").await.unwrap_or_default());
+	}
+
+	use hyper::header::CONTENT_TYPE;
+	use rss::{ChannelBuilder, Item};
+
+	// Get subreddit
+	let sub = req.param("sub").unwrap_or_default();
+	let post_sort = req.cookie("post_sort").map_or_else(|| "hot".to_string(), |c| c.value().to_string());
+	let sort = req.param("sort").unwrap_or_else(|| req.param("id").unwrap_or(post_sort));
+
+	// Get path
+	let path = format!("/r/{sub}/{sort}.json?{}", req.uri().query().unwrap_or_default());
+
+	// Get subreddit data
+	let subreddit = subreddit(&sub, false).await?;
+
+	// Get posts
+	let (posts, _) = Post::fetch(&path, false).await?;
+
+	// Build the RSS feed
+	let channel = ChannelBuilder::default()
+		.title(&subreddit.title)
+		.description(&subreddit.description)
+		.items(
+			posts
+				.into_iter()
+				.map(|post| Item {
+					title: Some(post.title.to_string()),
+					link: Some(utils::get_post_url(&post)),
+					author: Some(post.author.name),
+					content: Some(rewrite_urls(&post.body)),
+					..Default::default()
+				})
+				.collect::<Vec<_>>(),
+		)
+		.build();
+
+	// Serialize the feed to RSS
+	let body = channel.to_string().into_bytes();
+
+	// Create the HTTP response
+	let mut res = Response::new(Body::from(body));
+	res.headers_mut().insert(CONTENT_TYPE, hyper::header::HeaderValue::from_static("application/rss+xml"));
+
+	Ok(res)
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn test_fetching_subreddit() {
 	let subreddit = subreddit("rust", false).await;

src/user.rs

@@ -2,6 +2,7 @@
 use crate::client::json;
 use crate::server::RequestExt;
 use crate::utils::{error, filter_posts, format_url, get_filters, nsfw_landing, param, setting, template, Post, Preferences, User};
+use crate::{config, utils};
 use askama::Template;
 use hyper::{Body, Request, Response};
 use time::{macros::format_description, OffsetDateTime};
@@ -129,6 +130,56 @@ async fn user(name: &str) -> Result<User, String> {
 	})
 }
 
+pub async fn rss(req: Request<Body>) -> Result<Response<Body>, String> {
+	if config::get_setting("REDLIB_ENABLE_RSS").is_none() {
+		return Ok(error(req, "RSS is disabled on this instance.").await.unwrap_or_default());
+	}
+	use crate::utils::rewrite_urls;
+	use hyper::header::CONTENT_TYPE;
+	use rss::{ChannelBuilder, Item};
+
+	// Get user
+	let user_str = req.param("name").unwrap_or_default();
+
+	let listing = req.param("listing").unwrap_or_else(|| "overview".to_string());
+
+	// Get path
+	let path = format!("/user/{user_str}/{listing}.json?{}&raw_json=1", req.uri().query().unwrap_or_default(),);
+
+	// Get user
+	let user_obj = user(&user_str).await.unwrap_or_default();
+
+	// Get posts
+	let (posts, _) = Post::fetch(&path, false).await?;
+
+	// Build the RSS feed
+	let channel = ChannelBuilder::default()
+		.title(user_str)
+		.description(user_obj.description)
+		.items(
+			posts
+				.into_iter()
+				.map(|post| Item {
+					title: Some(post.title.to_string()),
+					link: Some(utils::get_post_url(&post)),
+					author: Some(post.author.name),
+					content: Some(rewrite_urls(&post.body)),
+					..Default::default()
+				})
+				.collect::<Vec<_>>(),
+		)
+		.build();
+
+	// Serialize the feed to RSS
+	let body = channel.to_string().into_bytes();
+
+	// Create the HTTP response
+	let mut res = Response::new(Body::from(body));
+	res.headers_mut().insert(CONTENT_TYPE, hyper::header::HeaderValue::from_static("application/rss+xml"));
+
+	Ok(res)
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn test_fetching_user() {
 	let user = user("spez").await;

src/utils.rs

@@ -1,5 +1,5 @@
 #![allow(dead_code)]
-use crate::config::get_setting;
+use crate::config::{self, get_setting};
 //
 // CRATES
 //
@@ -15,6 +15,7 @@ use serde_json::Value;
 use std::collections::{HashMap, HashSet};
 use std::env;
 use std::str::FromStr;
+use std::string::ToString;
 use time::{macros::format_description, Duration, OffsetDateTime};
 use url::Url;
 
@@ -327,6 +328,7 @@ pub struct Post {
 	pub gallery: Vec<GalleryMedia>,
 	pub awards: Awards,
 	pub nsfw: bool,
+	pub out_url: Option<String>,
 	pub ws_url: String,
 }
 
@@ -435,6 +437,7 @@ impl Post {
 				awards,
 				nsfw: post["data"]["over_18"].as_bool().unwrap_or_default(),
 				ws_url: val(post, "websocket_url"),
+				out_url: post["data"]["url_overridden_by_dest"].as_str().map(|a| a.to_string()),
 			});
 		}
 		Ok((posts, res["data"]["after"].as_str().unwrap_or_default().to_string()))
@@ -770,6 +773,7 @@ pub async fn parse_post(post: &Value) -> Post {
 		awards,
 		nsfw: post["data"]["over_18"].as_bool().unwrap_or_default(),
 		ws_url: val(post, "websocket_url"),
+		out_url: post["data"]["url_overridden_by_dest"].as_str().map(|a| a.to_string()),
 	}
 }
 
@@ -1082,6 +1086,16 @@ pub fn sfw_only() -> bool {
 	}
 }
 
+/// Returns true if the config/env variable REDLIB_ENABLE_RSS is set to "on".
+/// If this variable is set as such, the instance will enable RSS feeds.
+/// Otherwise, the instance will not provide RSS feeds.
+pub fn enable_rss() -> bool {
+	match get_setting("REDLIB_ENABLE_RSS") {
+		Some(val) => val == "on",
+		None => false,
+	}
+}
+
 // Determines if a request shoud redirect to a nsfw landing gate.
 pub fn should_be_nsfw_gated(req: &Request<Body>, req_url: &str) -> bool {
 	let sfw_instance = sfw_only();
@@ -1137,6 +1151,20 @@ pub fn url_path_basename(path: &str) -> String {
 	}
 }
 
+// Returns the URL of a post, as needed by RSS feeds
+pub fn get_post_url(post: &Post) -> String {
+	if let Some(out_url) = &post.out_url {
+		// Handle cross post
+		if out_url.starts_with("/r/") {
+			format!("{}{}", config::get_setting("REDLIB_FULL_URL").unwrap_or_default(), out_url)
+		} else {
+			out_url.to_string()
+		}
+	} else {
+		format!("{}{}", config::get_setting("REDLIB_FULL_URL").unwrap_or_default(), post.permalink)
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::{format_num, format_url, rewrite_urls};