diff --git a/butcher/src/main.rs b/butcher/src/main.rs
index fe04e77..724b451 100644
--- a/butcher/src/main.rs
+++ b/butcher/src/main.rs
@@ -1,6 +1,5 @@
 use std::{
     sync::Arc,
-    ops::Deref,
 };
 use futures::StreamExt;
 use cave::{
@@ -74,7 +73,7 @@ async fn main() {
             let post = Arc::new(post);
             store.save_post_tags(&post, is_profane(&profanity, &post).await).await;
 
-            let update_set = UpdateSet::from(post.deref());
+            let update_set = UpdateSet::from(&*post);
             if ! update_set.is_empty() {
                 trend_setter_tx.send(update_set).await.unwrap();
             }
diff --git a/butcher/src/trend_setter.rs b/butcher/src/trend_setter.rs
index 86b48aa..208d9db 100644
--- a/butcher/src/trend_setter.rs
+++ b/butcher/src/trend_setter.rs
@@ -62,7 +62,7 @@ pub fn start(mut store: Store) -> Tx {
                 }
                 std::collections::hash_map::Entry::Occupied(mut entry) => {
                     // merge into buffered
-                    for tag in tags.into_iter() {
+                    for tag in tags {
                         entry.get_mut().insert(tag);
                     }
                 }
@@ -70,7 +70,7 @@ pub fn start(mut store: Store) -> Tx {
         }
 
         loop {
-            let mut next_run = queue.keys().cloned().next();
+            let mut next_run = queue.keys().copied().next();
             if let Some(next_run_) = next_run {
                 let now = Instant::now();
                 if next_run_ <= now {
@@ -80,14 +80,14 @@ pub fn start(mut store: Store) -> Tx {
                     run(&language, buffered.clone(), &mut store).await.unwrap();
 
                     // update with next in queue
-                    next_run = queue.keys().cloned().next();
+                    next_run = queue.keys().copied().next();
                 } else {
                     tracing::trace!("next_run in {:?}", next_run_ - now);
                 }
             } else {
                 let languages = store.get_languages().await.unwrap();
                 tracing::info!("queue empty, filling from {} languages", languages.len());
-                for language in languages.into_iter() {
+                for language in languages {
                     enqueue(Some(language.clone()), &mut queue, &mut buffer, HashSet::new());
                 }
             }
diff --git a/buzzback/src/main.rs b/buzzback/src/main.rs
index 2226783..5dff3ea 100644
--- a/buzzback/src/main.rs
+++ b/buzzback/src/main.rs
@@ -84,7 +84,7 @@ async fn main() {
             } else if relay.ends_with("/actor") {
                 (relay.clone(), relay.replace("/actor", "/inbox"))
             } else {
-                panic!("Not sure how to deal with relay {}", relay);
+                panic!("Not sure how to deal with relay {relay}");
             };
         tracing::trace!("Following {}", &id);
         let follow = db::Follow {
diff --git a/cave/src/activitypub/digest.rs b/cave/src/activitypub/digest.rs
index 32d6eab..877cfe2 100644
--- a/cave/src/activitypub/digest.rs
+++ b/cave/src/activitypub/digest.rs
@@ -3,7 +3,7 @@ use http_digest_headers::{DigestHeader, DigestMethod};
 pub fn generate_header(body: &[u8]) -> Result<String, ()> {
     let mut digest_header = DigestHeader::new()
         .with_method(DigestMethod::SHA256, body)
-        .map(|h| format!("{}", h))
+        .map(|h| format!("{h}"))
         .map_err(|_| ())?;
 
     // mastodon expects uppercase algo name
diff --git a/cave/src/activitypub/mod.rs b/cave/src/activitypub/mod.rs
index f885453..532dfe0 100644
--- a/cave/src/activitypub/mod.rs
+++ b/cave/src/activitypub/mod.rs
@@ -49,7 +49,7 @@ pub struct Action<O> {
 }
 
 impl Action<serde_json::Value> {
-    pub fn object_id(&self) -> Option<&str> {
+    #[must_use] pub fn object_id(&self) -> Option<&str> {
         if let Some(id) = self.object.as_str() {
             Some(id)
         } else if let Some(object) = self.object.as_object() {
@@ -95,15 +95,15 @@ pub struct Post {
 }
 
 impl Post {
-    pub fn language(&self) -> Option<&str> {
+    #[must_use] pub fn language(&self) -> Option<&str> {
         self.content_map.keys()
-            .next().map(|s| s.as_str())
+            .next().map(std::string::String::as_str)
     }
 
-    /// Translate ActivityPub post to Mastodon client API post format
-    pub fn to_feed_post(self, actor: Actor) -> super::feed::Post {
+    /// Translate `ActivityPub` post to Mastodon client API post format
+    #[must_use] pub fn to_feed_post(self, actor: Actor) -> super::feed::Post {
         let language = self.language()
-            .map(|s| s.to_string());
+            .map(std::string::ToString::to_string);
         super::feed::Post {
             created_at: self.published,
             url: self.url.unwrap_or(self.id),
diff --git a/cave/src/config.rs b/cave/src/config.rs
index efe67d4..ce49c6d 100644
--- a/cave/src/config.rs
+++ b/cave/src/config.rs
@@ -6,7 +6,7 @@ impl<T: Sized + for<'a> serde::Deserialize<'a>> LoadConfig for T {
     fn load() -> Self {
         let path = std::env::args().nth(1)
             .expect("Call with config.yaml");
-        crate::systemd::status(&format!("Loading config file {}", path));
+        crate::systemd::status(&format!("Loading config file {path}"));
 
         let config_file = std::fs::read_to_string(path)
             .expect("read config");
diff --git a/cave/src/feed.rs b/cave/src/feed.rs
index 6c390c7..a103821 100644
--- a/cave/src/feed.rs
+++ b/cave/src/feed.rs
@@ -4,12 +4,12 @@ use futures::{Stream, StreamExt};
 use eventsource_stream::Eventsource;
 use reqwest::StatusCode;
 
-pub fn url_host(url: &str) -> Option<String> {
+#[must_use] pub fn url_host(url: &str) -> Option<String> {
     reqwest::Url::parse(url)
         .map_err(|e| tracing::warn!("Cannot parse url {:?}: {}", url, e))
         .ok()
         .and_then(|url| url.domain()
-                  .map(|host| host.to_lowercase())
+                  .map(str::to_lowercase)
         )
 }
 
@@ -25,7 +25,7 @@ pub struct Account {
 }
 
 impl Account {
-    pub fn host(&self) -> Option<String> {
+    #[must_use] pub fn host(&self) -> Option<String> {
         url_host(&self.url)
     }
 }
@@ -49,7 +49,7 @@ pub struct Mention {
 }
 
 impl Mention {
-    pub fn host(&self) -> Option<String> {
+    #[must_use] pub fn host(&self) -> Option<String> {
         url_host(&self.url)
     }
 }
@@ -82,27 +82,27 @@ pub struct Post {
 }
 
 impl Post {
-    pub fn url_host(&self) -> Option<String> {
+    #[must_use] pub fn url_host(&self) -> Option<String> {
         reqwest::Url::parse(&self.url)
             .ok()
             .and_then(|url| url.domain()
-                      .map(|host| host.to_owned())
+                      .map(std::borrow::ToOwned::to_owned)
             )
     }
 
-    pub fn user_id(&self) -> Option<String> {
+    #[must_use] pub fn user_id(&self) -> Option<String> {
         let username = self.account.username.to_lowercase();
         let host = self.url_host()?;
-        Some(format!("{}@{}", username, host))
+        Some(format!("{username}@{host}"))
     }
 
-    pub fn timestamp(&self) -> Option<DateTime<FixedOffset>> {
+    #[must_use] pub fn timestamp(&self) -> Option<DateTime<FixedOffset>> {
         DateTime::parse_from_rfc3339(&self.created_at)
             .ok()
     }
 
     /// clip "en-us" to "en"
-    pub fn lang(&self) -> Option<String> {
+    #[must_use] pub fn lang(&self) -> Option<String> {
         let language = match &self.language {
             Some(language) => language,
             None => return None,
@@ -214,7 +214,7 @@ pub struct Feed {
 impl Feed {
     /// Analyze time intervals between posts to estimate when to fetch
     /// next
-    pub fn mean_post_interval(&self) -> Option<Duration> {
+    #[must_use] pub fn mean_post_interval(&self) -> Option<Duration> {
         let mut timestamps = self.posts.iter()
             .filter_map(|post| post.timestamp())
             .collect::<Vec<_>>();
@@ -285,11 +285,11 @@ impl std::fmt::Display for StreamError {
     fn fmt(&self, fmt: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
         match self {
             StreamError::HttpStatus(code) =>
-                write!(fmt, "HTTP/{}", code),
+                write!(fmt, "HTTP/{code}"),
             StreamError::Http(e) =>
                 e.fmt(fmt),
             StreamError::InvalidContentType(ct) =>
-                write!(fmt, "Invalid Content-Type: {}", ct),
+                write!(fmt, "Invalid Content-Type: {ct}"),
         }
     }
 }
diff --git a/cave/src/firehose.rs b/cave/src/firehose.rs
index 396a0c6..79b2ce0 100644
--- a/cave/src/firehose.rs
+++ b/cave/src/firehose.rs
@@ -8,7 +8,7 @@ pub struct FirehoseFactory {
 }
 
 impl FirehoseFactory {
-    pub fn new(redis_url: String, redis_password_file: String) -> Self {
+    #[must_use] pub fn new(redis_url: String, redis_password_file: String) -> Self {
         let redis_password = std::fs::read_to_string(redis_password_file)
             .expect("redis_password_file");
         let mut redis_url = Url::parse(&redis_url)
diff --git a/cave/src/lib.rs b/cave/src/lib.rs
index 74b710b..f973ea2 100644
--- a/cave/src/lib.rs
+++ b/cave/src/lib.rs
@@ -18,6 +18,6 @@ pub const PERIODS: &[u64] = &[4, 24, 7 * 24];
 /// compare the selected period against how many multiples of preceding periods
 pub const PERIOD_COMPARE_WINDOW: u64 = 3;
 
-pub fn current_hour() -> u64 {
+#[must_use] pub fn current_hour() -> u64 {
     chrono::offset::Utc::now().timestamp() as u64 / 3600
 }
diff --git a/cave/src/live_file.rs b/cave/src/live_file.rs
index 74b97ca..14970eb 100644
--- a/cave/src/live_file.rs
+++ b/cave/src/live_file.rs
@@ -1,4 +1,4 @@
-use std::ops::Deref;
+
 use std::sync::Arc;
 use futures::{Future, StreamExt};
 use tokio::fs::File;
@@ -18,8 +18,7 @@ where
     let lock_ = lock.clone();
     let path = std::env::current_dir()
         .unwrap()
-        .join(path)
-        .to_path_buf();
+        .join(path).clone();
     let dir = path.parent().unwrap().to_path_buf();
 
     let path = Arc::new(RwLock::new(path));
@@ -28,7 +27,7 @@ where
     tokio::spawn(async move {
         let inotify = Inotify::init()
             .unwrap();
-        inotify.watches().add(dir.read().await.deref(), WatchMask::MODIFY | WatchMask::CREATE | WatchMask::MOVED_TO)
+        inotify.watches().add(&*dir.read().await, WatchMask::MODIFY | WatchMask::CREATE | WatchMask::MOVED_TO)
             .unwrap();
         tracing::debug!("Watching directory {:?}", &dir);
         inotify.into_event_stream([0; 1024])
@@ -45,7 +44,7 @@ where
                                 let dir = dir.read().await;
                                 let path = path.read().await;
                                 if dir.join(name) == *path {
-                                    match File::open(path.deref()).await {
+                                    match File::open(&*path).await {
                                         Ok(file) => {
                                             let t = f(file).await;
                                             *lock.write().await = t;
diff --git a/cave/src/posts_cache.rs b/cave/src/posts_cache.rs
index f38a8e0..e513f55 100644
--- a/cave/src/posts_cache.rs
+++ b/cave/src/posts_cache.rs
@@ -17,7 +17,7 @@ struct PostsCacheInner {
 }
 
 impl PostsCache {
-    pub fn new(size: usize) -> Self {
+    #[must_use] pub fn new(size: usize) -> Self {
         PostsCache {
             inner: Arc::new(Mutex::new(PostsCacheInner {
                 cache: HashSet::new(),
@@ -28,7 +28,7 @@ impl PostsCache {
     }
 
     // returns true if already exists
-    pub fn insert(&self, k: String) -> bool {
+    #[must_use] pub fn insert(&self, k: String) -> bool {
         let k = Arc::new(k);
 
         let mut inner = self.inner.lock().expect("lock");
@@ -45,7 +45,7 @@ impl PostsCache {
         inner.cache.insert(k);
 
         while inner.cache.len() > inner.size {
-            let oldest = inner.ages.keys().cloned().next().expect("ages first");
+            let oldest = inner.ages.keys().copied().next().expect("ages first");
             let oldest_k = inner.ages.remove(&oldest).expect("remove oldest");
             inner.cache.remove(&oldest_k);
         }
diff --git a/cave/src/store.rs b/cave/src/store.rs
index cc71878..26438f2 100644
--- a/cave/src/store.rs
+++ b/cave/src/store.rs
@@ -21,7 +21,7 @@ pub const IMAGES_PER_TAG: usize = 8;
 
 pub type Error = RedisError;
 
-/// wrapper so we can impl ManageConnection
+/// wrapper so we can impl `ManageConnection`
 struct RedisPool {
     redis_url: Url,
 }
@@ -197,14 +197,14 @@ impl Store {
             for spelling in spellings {
                 cmd.hincr(
                     &tag_key,
-                    format!("s:{}", spelling),
+                    format!("s:{spelling}"),
                     1
                 ).ignore();
             }
             // by instance
             cmd.hincr(
                 tag_key,
-                format!("h:{}", host),
+                format!("h:{host}"),
                 1
             ).ignore();
             if let Some(user_id) = &user_id {
@@ -228,24 +228,24 @@ impl Store {
             vec![]
         };
         let mut image_keys = vec![];
-        for (name, spellings) in tags.into_iter() {
+        for (name, spellings) in tags {
             // global
             store_tags(&mut cmd,
                 spellings.clone(),
-                format!("g:{}", name),
-                format!("u::{}:{}", hour, name),
+                format!("g:{name}"),
+                format!("u::{hour}:{name}"),
             );
             // by language
             if let Some(language) = &language {
                 store_tags(&mut cmd,
                     spellings,
-                    format!("l:{}:{}", language, name),
-                    format!("u:{}:{}:{}", language, hour, name),
+                    format!("l:{language}:{name}"),
+                    format!("u:{language}:{hour}:{name}"),
                 );
             }
 
             for image in &images {
-                let image_key = format!("i:{}", name);
+                let image_key = format!("i:{name}");
                 cmd.sadd(&image_key, image)
                     .ignore()
                     .expire(&image_key, TAG_EXPIRE as usize * 3600)
@@ -275,7 +275,7 @@ impl Store {
     }
 
     pub async fn save_host(&mut self, host: &str) -> Result<(), RedisError> {
-        let key = format!("h:{}", host);
+        let key = format!("h:{host}");
         redis::pipe()
             .set(&key, "1")
             .ignore()
@@ -286,7 +286,7 @@ impl Store {
     }
 
     pub async fn remove_host(&mut self, host: &str) -> Result<(), RedisError> {
-        redis::Cmd::del(format!("h:{}", host))
+        redis::Cmd::del(format!("h:{host}"))
             .query_async::<_, ()>(self)
             .await
     }
@@ -303,7 +303,7 @@ impl Store {
     }
 
     pub async fn get_tag_images(&mut self, tag: &str) -> Result<Vec<String>, RedisError> {
-        redis::Cmd::smembers(format!("i:{}", tag))
+        redis::Cmd::smembers(format!("i:{tag}"))
             .query_async(self)
             .await
     }
@@ -332,7 +332,7 @@ impl Store {
     }
 
     pub async fn scan_prefix<'a>(&'a mut self, prefix: &'a str) -> Result<impl Stream<Item = String> + '_, RedisError> {
-        let keys = self.scan(&format!("{}*", prefix))
+        let keys = self.scan(&format!("{prefix}*"))
             .await?
             .map(|key| key[prefix.len()..].to_string());
         Ok(keys)
@@ -388,7 +388,7 @@ impl Store {
             .into_iter();
 
         let mut results = Vec::with_capacity(names.len());
-        for name in names.into_iter() {
+        for name in names {
             let hash_values = if let Some(Value::Bulk(hash_values)) = values.next() {
                 hash_values
             } else {
@@ -417,7 +417,7 @@ impl Store {
         }
         let sets: Vec<Vec<String>> = cmd.query_async(self)
             .await?;
-        let results = periods.iter().cloned()
+        let results = periods.iter().copied()
             .zip(sets.into_iter())
             .collect();
         Ok(results)
@@ -472,8 +472,8 @@ impl Store {
         tag: &str,
     ) -> Result<(), RedisError> {
         let key = match language {
-            Some(language) => format!("l:{}:{}", language, tag),
-            None => format!("g:{}", tag),
+            Some(language) => format!("l:{language}:{tag}"),
+            None => format!("g:{tag}"),
         };
         redis::Cmd::del(key)
             .query_async(self)
@@ -483,16 +483,16 @@ impl Store {
 
 fn tag_key(language: &Option<String>, name: &str) -> String {
     match language {
-        Some(language) => format!("l:{}:{}", language, name),
-        None => format!("g:{}", name),
+        Some(language) => format!("l:{language}:{name}"),
+        None => format!("g:{name}"),
     }
 }
 
 fn pool_key(language: &Option<String>, period: u64) -> String {
     match language {
         Some(language) =>
-            format!("q:{}:{}", period, language),
+            format!("q:{period}:{language}"),
         None =>
-            format!("q:{}", period),
+            format!("q:{period}"),
     }
 }
diff --git a/cave/src/systemd.rs b/cave/src/systemd.rs
index d824def..447606d 100644
--- a/cave/src/systemd.rs
+++ b/cave/src/systemd.rs
@@ -4,7 +4,7 @@ pub fn status(text: &str) {
 }
 
 pub fn extend_timeout(usec: u64) {
-    systemd::daemon::notify(false, [(systemd::daemon::STATE_EXTEND_TIMEOUT_USEC, format!("{}", usec))].iter())
+    systemd::daemon::notify(false, [(systemd::daemon::STATE_EXTEND_TIMEOUT_USEC, format!("{usec}"))].iter())
         .unwrap();
 }
 
diff --git a/cave/src/trend_tag.rs b/cave/src/trend_tag.rs
index 9238d0f..da6552a 100644
--- a/cave/src/trend_tag.rs
+++ b/cave/src/trend_tag.rs
@@ -19,7 +19,7 @@ impl TrendTag {
         let mut other = Vec::with_capacity(hash_values.len() / 2);
 
         let mut key: Option<String> = None;
-        for value in hash_values.into_iter() {
+        for value in hash_values {
             if let Some(key) = key.take() {
                 if let Ok(value) = str::parse(&value) {
                     other.push((key, value));
@@ -36,7 +36,7 @@ impl TrendTag {
         }
     }
 
-    pub fn score(&self, period: u64, until: u64) -> f64 {
+    #[must_use] pub fn score(&self, period: u64, until: u64) -> f64 {
         // ignore spam that comes from only 1 instance
         if self.hosts().nth(1).is_none() {
             return -1.;
@@ -48,7 +48,7 @@ impl TrendTag {
         let mut before_hours = 0;
         let mut after_mentions = 0;
 
-        for (hour, mentions) in self.hour_users.iter().cloned() {
+        for (hour, mentions) in self.hour_users.iter().copied() {
             if hour > from {
                 if mentions > 1 {
                     after_mentions += mentions;
@@ -66,22 +66,22 @@ impl TrendTag {
         }
 
         let before = if before_hours > 0 && before_mentions > 0 {
-            (before_mentions as f64) / (before_hours as f64)
+            (before_mentions as f64) / f64::from(before_hours)
         } else { 0.1 };
         let after = (after_mentions as f64) / (period as f64);
         after / before
     }
 
-    pub fn hour_scores_data(&self, period: u64) -> String {
+    #[must_use] pub fn hour_scores_data(&self, period: u64) -> String {
         let offset = self.hour_users.len().saturating_sub(period as usize);
         self.hour_users[offset..]
             .iter()
             .map(|(_, count)| *count)
             .enumerate()
             .map(|(i, count)| if i == 0 {
-                format!("{}", count)
+                format!("{count}")
             } else {
-                format!(" {}", count)
+                format!(" {count}")
             })
             .collect()
     }
@@ -101,10 +101,10 @@ impl TrendTag {
             })
     }
 
-    pub fn spelling(&self) -> &str {
+    #[must_use] pub fn spelling(&self) -> &str {
         self.spellings()
             .map(|(count, spelling)| {
-                if spelling.chars().any(|c| c.is_uppercase()) {
+                if spelling.chars().any(char::is_uppercase) {
                     // favor captialized spelling
                     (10 * count, spelling)
                 } else {
@@ -112,8 +112,7 @@ impl TrendTag {
                 }
             })
             .max()
-            .map(|(_count, spelling)| spelling)
-            .unwrap_or(&self.name)
+            .map_or(&self.name, |(_count, spelling)| spelling)
     }
 
     pub fn hosts(&self) -> impl Iterator<Item = (usize, &str)> {
@@ -132,7 +131,7 @@ impl TrendTag {
     }
 
     /// ordered by count
-    pub fn hosts_set(&self) -> BTreeSet<(usize, &str)> {
+    #[must_use] pub fn hosts_set(&self) -> BTreeSet<(usize, &str)> {
         self.hosts().collect()
     }
 }
diff --git a/gatherer/src/html_template.rs b/gatherer/src/html_template.rs
index ab137cf..b7b3351 100644
--- a/gatherer/src/html_template.rs
+++ b/gatherer/src/html_template.rs
@@ -15,7 +15,7 @@ where
             Ok(html) => Html(html).into_response(),
             Err(err) => (
                 StatusCode::INTERNAL_SERVER_ERROR,
-                format!("Failed to render template. Error: {}", err),
+                format!("Failed to render template. Error: {err}"),
             )
                 .into_response(),
         }
diff --git a/gatherer/src/http_server.rs b/gatherer/src/http_server.rs
index ac607bf..bf04dd9 100644
--- a/gatherer/src/http_server.rs
+++ b/gatherer/src/http_server.rs
@@ -68,7 +68,7 @@ impl ServerState {
                     .into_iter()
                     .enumerate()
                     .flat_map(|(i, url)| if i == 0 {
-                        ["".to_owned(), url]
+                        [String::new(), url]
                     } else {
                         [" ".to_owned(), url]
                     })
@@ -127,12 +127,7 @@ impl TrendsPage {
         // service is very much alive:
         systemd::watchdog();
 
-        TrendsPage {
-            results,
-            language,
-            languages,
-            tag_images,
-        }
+        TrendsPage { language, languages, results, tag_images }
     }
 
     fn template(self) -> HtmlTemplate<Self> {
diff --git a/gatherer/src/http_server/token_collect.rs b/gatherer/src/http_server/token_collect.rs
index 72c0bcc..6ff08c5 100644
--- a/gatherer/src/http_server/token_collect.rs
+++ b/gatherer/src/http_server/token_collect.rs
@@ -18,7 +18,7 @@ async fn collect_token(
 ) -> Result<(), String> {
     // try a few registered apps until one works
     for (client_id, client_secret) in db.get_apps(host).await
-        .map_err(|e| format!("{}", e))?
+        .map_err(|e| format!("{e}"))?
     {
         let app = oauth::Application {
             client_id,
@@ -39,7 +39,7 @@ async fn collect_token(
         }
     }
 
-    Err(format!("No registered app found for instance {}", host))
+    Err(format!("No registered app found for instance {host}"))
 }
 
 #[derive(serde::Deserialize)]
diff --git a/gatherer/src/http_server/token_donate.rs b/gatherer/src/http_server/token_donate.rs
index deb87d4..e59a6ad 100644
--- a/gatherer/src/http_server/token_donate.rs
+++ b/gatherer/src/http_server/token_donate.rs
@@ -60,7 +60,7 @@ pub async fn post_token_donate(
             Ok(app) => app,
             Err(e) => {
                 tracing::error!("Canont register OAuth app: {}", e);
-                return PostTokenDonateResult::Error(format!("{}", e));
+                return PostTokenDonateResult::Error(format!("{e}"));
             }
         };
         db.add_app(&form.instance, &app.client_id, &app.client_secret).await
diff --git a/gatherer/src/oauth.rs b/gatherer/src/oauth.rs
index 45144c2..3d62d1a 100644
--- a/gatherer/src/oauth.rs
+++ b/gatherer/src/oauth.rs
@@ -32,7 +32,7 @@ const SCOPES: &str = "read:statuses";
 
 impl Application {
     pub async fn register(client: &reqwest::Client, host: &str) -> Result<Self, reqwest::Error> {
-        let url = format!("https://{}/api/v1/apps", host);
+        let url = format!("https://{host}/api/v1/apps");
         let form = AppRegistration {
             client_name: "#FediBuzz".to_string(),
             website: "https://fedi.buzz/".to_string(),
@@ -49,7 +49,7 @@ impl Application {
     }
 
     pub fn generate_redirect_url(host: &str) -> String {
-        format!("https://fedi.buzz/token/collect/{}", host)
+        format!("https://fedi.buzz/token/collect/{host}")
     }
 
     pub fn generate_auth_url(&self, host: &str) -> String {
@@ -63,7 +63,7 @@ impl Application {
     }
 
     pub async fn obtain_token(&self, client: &reqwest::Client, host: &str, code: String) -> Result<String, reqwest::Error> {
-        let url = format!("https://{}/oauth/token", host);
+        let url = format!("https://{host}/oauth/token");
         let form = TokenRequest {
             grant_type: "authorization_code".to_string(),
             scope: SCOPES.to_string(),
diff --git a/gatherer/src/trends.rs b/gatherer/src/trends.rs
index 239371e..3e7ba98 100644
--- a/gatherer/src/trends.rs
+++ b/gatherer/src/trends.rs
@@ -54,7 +54,7 @@ impl TrendAnalyzer {
 
         let until = current_hour();
         let mut analyzers: Vec<TrendAnalyzer> = periods.iter()
-            .cloned()
+            .copied()
             .map(|period| TrendAnalyzer {
                 period,
                 until,
@@ -75,7 +75,7 @@ impl TrendAnalyzer {
         metrics::histogram!("trends_page_time", t2 - t1, "step" => "get_trend_pools", "lang" => lang);
         metrics::histogram!("trends_page_time", t3 - t2, "step" => "get_trend_tags", "lang" => lang);
         metrics::histogram!("trends_page_tags", tags_len as f64, "lang" => lang);
-        for trend_tag in trend_tags.into_iter() {
+        for trend_tag in trend_tags {
             let trend_tag = Arc::new(trend_tag);
             let name = Arc::new(trend_tag.name.clone());
             for analyzer in &mut analyzers {
diff --git a/hunter/src/main.rs b/hunter/src/main.rs
index d6741b3..9272647 100644
--- a/hunter/src/main.rs
+++ b/hunter/src/main.rs
@@ -50,7 +50,7 @@ async fn run() {
     cave::systemd::status("Starting scheduler");
     let mut scheduler = scheduler::Scheduler::new(block_list.clone());
     cave::systemd::status("Loading known hosts from config");
-    for host in config.hosts.into_iter() {
+    for host in config.hosts {
         scheduler.introduce(InstanceHost::just_host(host)).await;
     }
     #[cfg(not(dev))]
diff --git a/hunter/src/scheduler.rs b/hunter/src/scheduler.rs
index eebb814..c6c858c 100644
--- a/hunter/src/scheduler.rs
+++ b/hunter/src/scheduler.rs
@@ -136,7 +136,7 @@ impl Scheduler {
     pub fn dequeue(&mut self) -> Result<InstanceHost, Duration> {
         let now = Instant::now();
 
-        if let Some(time) = self.queue.keys().next().cloned() {
+        if let Some(time) = self.queue.keys().next().copied() {
             if time <= now {
                 self.queue.remove(&time)
                     .ok_or(Duration::from_secs(1))
diff --git a/hunter/src/worker.rs b/hunter/src/worker.rs
index 3874255..e274738 100644
--- a/hunter/src/worker.rs
+++ b/hunter/src/worker.rs
@@ -24,7 +24,7 @@ impl RobotsTxt {
         client: &reqwest::Client,
         host: &Host,
     ) -> Self {
-        let url = format!("https://{}/robots.txt", host);
+        let url = format!("https://{host}/robots.txt");
         metrics::increment_gauge!("hunter_requests", 1.0, "type" => "robotstxt");
         let robot = async {
             let body = client.get(url)
@@ -172,7 +172,7 @@ async fn fetch_timeline(
     robots_txt: RobotsTxt,
     host: &Host,
 ) -> Result<(Option<f64>, Option<Duration>), reqwest::Error> {
-    let url = format!("https://{}/api/v1/timelines/public?limit=40", host);
+    let url = format!("https://{host}/api/v1/timelines/public?limit=40");
     if ! robots_txt.allowed(&url) {
         tracing::warn!("Timeline of {} forbidden by robots.txt", host);
         return Ok((None, None));
@@ -192,7 +192,7 @@ async fn fetch_timeline(
     let mean_interval = feed.mean_post_interval();
 
     let (new_post_ratio, introduce_hosts) = process_posts(&mut store, posts_cache, block_list, host, feed.posts.into_iter()).await;
-    for introduce_host in introduce_hosts.into_iter() {
+    for introduce_host in introduce_hosts {
         message_tx.send(Message::IntroduceHost(introduce_host)).unwrap();
     }
 
@@ -250,7 +250,7 @@ async fn process_posts(
             }
 
             let t2 = Instant::now();
-            metrics::histogram!("hunter_post_process_seconds", t2 - t1)
+            metrics::histogram!("hunter_post_process_seconds", t2 - t1);
         }
     }
     tracing::trace!("{}: {}/{} new posts", host, new_posts, posts_len);
@@ -299,9 +299,9 @@ async fn open_stream(
     robots_txt: RobotsTxt,
     host: Host,
 ) -> Result<(&'static str, impl Future<Output = usize>), String> {
-    let url = format!("https://{}/api/v1/streaming/public", host);
+    let url = format!("https://{host}/api/v1/streaming/public");
     if ! robots_txt.allowed(&url) {
-        return Err(format!("Streaming of {} forbidden by robots.txt", host));
+        return Err(format!("Streaming of {host} forbidden by robots.txt"));
     }
     // free as early as possible
     drop(robots_txt);
@@ -346,7 +346,7 @@ async fn open_stream(
     }
 
     let stream = stream.map_err(|e| {
-        format!("Stream error for {}: {}", host, e)
+        format!("Stream error for {host}: {e}")
     })?;
 
     Ok((stats_key, stream.fold(0, move |post_count, post| {
@@ -358,7 +358,7 @@ async fn open_stream(
         async move {
             let (_, introduce_hosts) =
                 process_posts(&mut store, &posts_cache, block_list, &host, [post].into_iter()).await;
-            for introduce_host in introduce_hosts.into_iter() {
+            for introduce_host in introduce_hosts {
                 message_tx.send(Message::IntroduceHost(introduce_host)).unwrap();
             }
             post_count + 1
diff --git a/smokestack/src/main.rs b/smokestack/src/main.rs
index 77a34fb..f53f952 100644
--- a/smokestack/src/main.rs
+++ b/smokestack/src/main.rs
@@ -5,7 +5,7 @@ use std::{
         RwLock,
     },
 };
-use ansi_term::Colour::{self, *};
+use ansi_term::Colour::{self, Black, RGB, Red, Yellow};
 use futures::{Stream, StreamExt};
 use tokio::{
     io::AsyncWriteExt,
@@ -216,7 +216,7 @@ async fn main() {
         tokio::spawn(async move {
             while let Some(msg) = pipe.rx.recv().await {
                 match socket.write_all(&msg[..]).await {
-                    Ok(_) => {}
+                    Ok(()) => {}
                     Err(_) => break,
                 }
             }