refactor: split sticky-cookie into a separated feature

Cargo.toml

@@ -12,12 +12,13 @@ publish = false
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [features]
-default = ["http3"]
+default = ["http3", "sticky-cookie"]
 http3 = ["quinn", "h3", "h3-quinn"]
+sticky-cookie = ["base64", "sha2", "chrono"]
 
 [dependencies]
 anyhow = "1.0.71"
-clap = { version = "4.3.3", features = ["std", "cargo", "wrap_help"] }
+clap = { version = "4.3.4", features = ["std", "cargo", "wrap_help"] }
 rand = "0.8.5"
 toml = { version = "0.7.4", default-features = false, features = ["parse"] }
 rustc-hash = "1.1.0"
@@ -51,7 +52,7 @@ hyper-rustls = { version = "0.24.0", default-features = false, features = [
 ] }
 tokio-rustls = { version = "0.24.1", features = ["early-data"] }
 rustls-pemfile = "1.0.2"
-rustls = { version = "0.21.1", default-features = false }
+rustls = { version = "0.21.2", default-features = false }
 webpki = "0.22.0"
 
 # logging
@@ -65,14 +66,14 @@ h3 = { path = "./h3/h3/", optional = true }
 # h3-quinn = { path = "./h3/h3-quinn/", optional = true }
 h3-quinn = { path = "./h3-quinn/", optional = true } # Tentative to support rustls-0.21
 
-# cookie handling
+# cookie handling for sticky cookie
 chrono = { version = "0.4.26", default-features = false, features = [
   "unstable-locales",
   "alloc",
   "clock",
-] }
+], optional = true }
-base64 = "0.21.2"
+base64 = { version = "0.21.2", optional = true }
-sha2 = { version = "0.10.6", default-features = false }
+sha2 = { version = "0.10.6", default-features = false, optional = true }
 
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]

TODO.md

@@ -3,6 +3,13 @@
 - Improvement of path matcher
 - More flexible option for rewriting path
 - Refactoring
+
+  Split `backend` module into three parts
+
+  - backend(s): struct containing info, defined for each served domain with multiple paths
+  - upstream/upstream group: information on targeted destinations for each set of (a domain + a path)
+  - load-balance: load balancing mod for a domain + path
+
 - Unit tests
 - Options to serve custom http_error page.
 - Prometheus metrics

h3

@@ -1 +1 @@
-Subproject commit 22da9387f19d724852b3bf1dfd7e66f0fd45cb81
+Subproject commit 3ef7c1a37b635e8446322d8f8d3a68580a208ad8

src/backend/load_balance.rs

@@ -1,14 +1,13 @@
-use super::{load_balance_sticky_cookie::StickyCookieConfig, LbContext, Upstream};
+#[cfg(feature = "sticky-cookie")]
-use crate::{constants::STICKY_COOKIE_NAME, log::*};
+pub use super::{
+  load_balance_sticky::{LbStickyRoundRobin, LbStickyRoundRobinBuilder},
+  sticky_cookie::StickyCookie,
+};
 use derive_builder::Builder;
 use rand::Rng;
-use rustc_hash::FxHashMap as HashMap;
+use std::sync::{
-use std::{
-  borrow::Cow,
-  sync::{
   atomic::{AtomicUsize, Ordering},
   Arc,
-  },
 };
 
 /// Constants to specify a load balance option
@@ -16,6 +15,7 @@ pub(super) mod load_balance_options {
   pub const FIX_TO_FIRST: &str = "none";
   pub const ROUND_ROBIN: &str = "round_robin";
   pub const RANDOM: &str = "random";
+  #[cfg(feature = "sticky-cookie")]
   pub const STICKY_ROUND_ROBIN: &str = "sticky";
 }
 
@@ -27,7 +27,7 @@ pub(super) struct PointerToUpstream {
   pub context_lb: Option<LbContext>,
 }
 /// Trait for LB
-trait LbWithPointer {
+pub(super) trait LbWithPointer {
   fn get_ptr(&self, req_info: Option<&LbContext>) -> PointerToUpstream;
 }
 
@@ -85,123 +85,6 @@ impl LbWithPointer for LbRandom {
   }
 }
 
-#[derive(Debug, Clone, Builder)]
-/// Round Robin LB object in the sticky cookie manner
-pub struct LbStickyRoundRobin {
-  #[builder(default)]
-  /// Pointer to the index of the last served upstream destination
-  ptr: Arc<AtomicUsize>,
-  #[builder(setter(custom), default)]
-  /// Number of upstream destinations
-  num_upstreams: usize,
-  #[builder(setter(custom))]
-  /// Information to build the cookie to stick clients to specific backends
-  pub sticky_config: StickyCookieConfig,
-  #[builder(setter(custom))]
-  /// Hashmaps:
-  /// - Hashmap that maps server indices to server id (string)
-  /// - Hashmap that maps server ids (string) to server indices, for fast reverse lookup
-  upstream_maps: UpstreamMap,
-}
-#[derive(Debug, Clone)]
-pub struct UpstreamMap {
-  /// Hashmap that maps server indices to server id (string)
-  upstream_index_map: Vec<String>,
-  /// Hashmap that maps server ids (string) to server indices, for fast reverse lookup
-  upstream_id_map: HashMap<String, usize>,
-}
-impl LbStickyRoundRobinBuilder {
-  pub fn num_upstreams(&mut self, v: &usize) -> &mut Self {
-    self.num_upstreams = Some(*v);
-    self
-  }
-  pub fn sticky_config(&mut self, server_name: &str, path_opt: &Option<String>) -> &mut Self {
-    self.sticky_config = Some(StickyCookieConfig {
-      name: STICKY_COOKIE_NAME.to_string(), // TODO: config等で変更できるように
-      domain: server_name.to_ascii_lowercase(),
-      path: if let Some(v) = path_opt {
-        v.to_ascii_lowercase()
-      } else {
-        "/".to_string()
-      },
-      duration: 300, // TODO: config等で変更できるように
-    });
-    self
-  }
-  pub fn upstream_maps(&mut self, upstream_vec: &[Upstream]) -> &mut Self {
-    let upstream_index_map: Vec<String> = upstream_vec
-      .iter()
-      .enumerate()
-      .map(|(i, v)| v.calculate_id_with_index(i))
-      .collect();
-    let mut upstream_id_map = HashMap::default();
-    for (i, v) in upstream_index_map.iter().enumerate() {
-      upstream_id_map.insert(v.to_string(), i);
-    }
-    self.upstream_maps = Some(UpstreamMap {
-      upstream_index_map,
-      upstream_id_map,
-    });
-    self
-  }
-}
-impl<'a> LbStickyRoundRobin {
-  fn simple_increment_ptr(&self) -> usize {
-    // Get a current count of upstream served
-    let current_ptr = self.ptr.load(Ordering::Relaxed);
-
-    if current_ptr < self.num_upstreams - 1 {
-      self.ptr.fetch_add(1, Ordering::Relaxed)
-    } else {
-      // Clear the counter
-      self.ptr.fetch_and(0, Ordering::Relaxed)
-    }
-  }
-  /// This is always called only internally. So 'unwrap()' is executed.
-  fn get_server_id_from_index(&self, index: usize) -> String {
-    self.upstream_maps.upstream_index_map.get(index).unwrap().to_owned()
-  }
-  /// This function takes value passed from outside. So 'result' is used.
-  fn get_server_index_from_id(&self, id: impl Into<Cow<'a, str>>) -> Option<usize> {
-    let id_str = id.into().to_string();
-    self.upstream_maps.upstream_id_map.get(&id_str).map(|v| v.to_owned())
-  }
-}
-impl LbWithPointer for LbStickyRoundRobin {
-  fn get_ptr(&self, req_info: Option<&LbContext>) -> PointerToUpstream {
-    // If given context is None or invalid (not contained), get_ptr() is invoked to increment the pointer.
-    // Otherwise, get the server index indicated by the server_id inside the cookie
-    let ptr = match req_info {
-      None => {
-        debug!("No sticky cookie");
-        self.simple_increment_ptr()
-      }
-      Some(context) => {
-        let server_id = &context.sticky_cookie.value.value;
-        if let Some(server_index) = self.get_server_index_from_id(server_id) {
-          debug!("Valid sticky cookie: id={}, index={}", server_id, server_index);
-          server_index
-        } else {
-          debug!("Invalid sticky cookie: id={}", server_id);
-          self.simple_increment_ptr()
-        }
-      }
-    };
-
-    // Get the server id from the ptr.
-    // TODO: This should be simplified and optimized if ptr is not changed (id value exists in cookie).
-    let upstream_id = self.get_server_id_from_index(ptr);
-    let new_cookie = self.sticky_config.build_sticky_cookie(upstream_id).unwrap();
-    let new_context = Some(LbContext {
-      sticky_cookie: new_cookie,
-    });
-    PointerToUpstream {
-      ptr,
-      context_lb: new_context,
-    }
-  }
-}
-
 #[derive(Debug, Clone)]
 /// Load Balancing Option
 pub enum LoadBalance {
@@ -211,6 +94,7 @@ pub enum LoadBalance {
   Random(LbRandom),
   /// Simple round robin without session persistance
   RoundRobin(LbRoundRobin),
+  #[cfg(feature = "sticky-cookie")]
   /// Round robin with session persistance using cookie
   StickyRoundRobin(LbStickyRoundRobin),
 }
@@ -222,7 +106,7 @@ impl Default for LoadBalance {
 
 impl LoadBalance {
   /// Get the index of the upstream serving the incoming request
-  pub(super) fn get_context(&self, context_to_lb: &Option<LbContext>) -> PointerToUpstream {
+  pub(super) fn get_context(&self, _context_to_lb: &Option<LbContext>) -> PointerToUpstream {
     match self {
       LoadBalance::FixToFirst => PointerToUpstream {
         ptr: 0usize,
@@ -230,10 +114,22 @@ impl LoadBalance {
       },
       LoadBalance::RoundRobin(ptr) => ptr.get_ptr(None),
       LoadBalance::Random(ptr) => ptr.get_ptr(None),
+      #[cfg(feature = "sticky-cookie")]
       LoadBalance::StickyRoundRobin(ptr) => {
         // Generate new context if sticky round robin is enabled.
-        ptr.get_ptr(context_to_lb.as_ref())
+        ptr.get_ptr(_context_to_lb.as_ref())
       }
     }
   }
 }
+
+#[derive(Debug, Clone)]
+/// Struct to handle the sticky cookie string,
+/// - passed from Rp module (http handler) to LB module, manipulated from req, only StickyCookieValue exists.
+/// - passed from LB module to Rp module (http handler), will be inserted into res, StickyCookieValue and Info exist.
+pub struct LbContext {
+  #[cfg(feature = "sticky-cookie")]
+  pub sticky_cookie: StickyCookie,
+  #[cfg(not(feature = "sticky-cookie"))]
+  pub sticky_cookie: (),
+}

src/backend/load_balance_sticky.rs

@@ -0,0 +1,132 @@
+use super::{
+  load_balance::{LbContext, LbWithPointer, PointerToUpstream},
+  sticky_cookie::StickyCookieConfig,
+  Upstream,
+};
+use crate::{constants::STICKY_COOKIE_NAME, log::*};
+use derive_builder::Builder;
+use rustc_hash::FxHashMap as HashMap;
+use std::{
+  borrow::Cow,
+  sync::{
+    atomic::{AtomicUsize, Ordering},
+    Arc,
+  },
+};
+
+#[derive(Debug, Clone, Builder)]
+/// Round Robin LB object in the sticky cookie manner
+pub struct LbStickyRoundRobin {
+  #[builder(default)]
+  /// Pointer to the index of the last served upstream destination
+  ptr: Arc<AtomicUsize>,
+  #[builder(setter(custom), default)]
+  /// Number of upstream destinations
+  num_upstreams: usize,
+  #[builder(setter(custom))]
+  /// Information to build the cookie to stick clients to specific backends
+  pub sticky_config: StickyCookieConfig,
+  #[builder(setter(custom))]
+  /// Hashmaps:
+  /// - Hashmap that maps server indices to server id (string)
+  /// - Hashmap that maps server ids (string) to server indices, for fast reverse lookup
+  upstream_maps: UpstreamMap,
+}
+#[derive(Debug, Clone)]
+pub struct UpstreamMap {
+  /// Hashmap that maps server indices to server id (string)
+  upstream_index_map: Vec<String>,
+  /// Hashmap that maps server ids (string) to server indices, for fast reverse lookup
+  upstream_id_map: HashMap<String, usize>,
+}
+impl LbStickyRoundRobinBuilder {
+  pub fn num_upstreams(&mut self, v: &usize) -> &mut Self {
+    self.num_upstreams = Some(*v);
+    self
+  }
+  pub fn sticky_config(&mut self, server_name: &str, path_opt: &Option<String>) -> &mut Self {
+    self.sticky_config = Some(StickyCookieConfig {
+      name: STICKY_COOKIE_NAME.to_string(), // TODO: config等で変更できるように
+      domain: server_name.to_ascii_lowercase(),
+      path: if let Some(v) = path_opt {
+        v.to_ascii_lowercase()
+      } else {
+        "/".to_string()
+      },
+      duration: 300, // TODO: config等で変更できるように
+    });
+    self
+  }
+  pub fn upstream_maps(&mut self, upstream_vec: &[Upstream]) -> &mut Self {
+    let upstream_index_map: Vec<String> = upstream_vec
+      .iter()
+      .enumerate()
+      .map(|(i, v)| v.calculate_id_with_index(i))
+      .collect();
+    let mut upstream_id_map = HashMap::default();
+    for (i, v) in upstream_index_map.iter().enumerate() {
+      upstream_id_map.insert(v.to_string(), i);
+    }
+    self.upstream_maps = Some(UpstreamMap {
+      upstream_index_map,
+      upstream_id_map,
+    });
+    self
+  }
+}
+impl<'a> LbStickyRoundRobin {
+  fn simple_increment_ptr(&self) -> usize {
+    // Get a current count of upstream served
+    let current_ptr = self.ptr.load(Ordering::Relaxed);
+
+    if current_ptr < self.num_upstreams - 1 {
+      self.ptr.fetch_add(1, Ordering::Relaxed)
+    } else {
+      // Clear the counter
+      self.ptr.fetch_and(0, Ordering::Relaxed)
+    }
+  }
+  /// This is always called only internally. So 'unwrap()' is executed.
+  fn get_server_id_from_index(&self, index: usize) -> String {
+    self.upstream_maps.upstream_index_map.get(index).unwrap().to_owned()
+  }
+  /// This function takes value passed from outside. So 'result' is used.
+  fn get_server_index_from_id(&self, id: impl Into<Cow<'a, str>>) -> Option<usize> {
+    let id_str = id.into().to_string();
+    self.upstream_maps.upstream_id_map.get(&id_str).map(|v| v.to_owned())
+  }
+}
+impl LbWithPointer for LbStickyRoundRobin {
+  fn get_ptr(&self, req_info: Option<&LbContext>) -> PointerToUpstream {
+    // If given context is None or invalid (not contained), get_ptr() is invoked to increment the pointer.
+    // Otherwise, get the server index indicated by the server_id inside the cookie
+    let ptr = match req_info {
+      None => {
+        debug!("No sticky cookie");
+        self.simple_increment_ptr()
+      }
+      Some(context) => {
+        let server_id = &context.sticky_cookie.value.value;
+        if let Some(server_index) = self.get_server_index_from_id(server_id) {
+          debug!("Valid sticky cookie: id={}, index={}", server_id, server_index);
+          server_index
+        } else {
+          debug!("Invalid sticky cookie: id={}", server_id);
+          self.simple_increment_ptr()
+        }
+      }
+    };
+
+    // Get the server id from the ptr.
+    // TODO: This should be simplified and optimized if ptr is not changed (id value exists in cookie).
+    let upstream_id = self.get_server_id_from_index(ptr);
+    let new_cookie = self.sticky_config.build_sticky_cookie(upstream_id).unwrap();
+    let new_context = Some(LbContext {
+      sticky_cookie: new_cookie,
+    });
+    PointerToUpstream {
+      ptr,
+      context_lb: new_context,
+    }
+  }
+}

src/backend/mod.rs

@@ -1,11 +1,15 @@
 mod load_balance;
-mod load_balance_sticky_cookie;
+#[cfg(feature = "sticky-cookie")]
+mod load_balance_sticky;
+#[cfg(feature = "sticky-cookie")]
+mod sticky_cookie;
 mod upstream;
 mod upstream_opts;
 
+#[cfg(feature = "sticky-cookie")]
+pub use self::sticky_cookie::{StickyCookie, StickyCookieValue};
 pub use self::{
-  load_balance::LoadBalance,
+  load_balance::{LbContext, LoadBalance},
-  load_balance_sticky_cookie::{LbContext, StickyCookie, StickyCookieBuilder, StickyCookieValue},
   upstream::{ReverseProxy, Upstream, UpstreamGroup, UpstreamGroupBuilder},
   upstream_opts::UpstreamOption,
 };
@@ -270,15 +274,22 @@ impl Backends {
 
             let mut server_config_local = if client_ca_roots_local.is_empty() {
               // with no client auth, enable http1.1 -- 3
+              #[cfg(not(feature = "http3"))]
+              {
+                ServerConfig::builder()
+                  .with_safe_defaults()
+                  .with_no_client_auth()
+                  .with_cert_resolver(Arc::new(resolver_local))
+              }
+              #[cfg(feature = "http3")]
+              {
                 let mut sc = ServerConfig::builder()
                   .with_safe_defaults()
                   .with_no_client_auth()
                   .with_cert_resolver(Arc::new(resolver_local));
-              #[cfg(feature = "http3")]
-              {
                 sc.alpn_protocols = vec![b"h3".to_vec(), b"hq-29".to_vec()]; // TODO: remove hq-29 later?
-              }
                 sc
+              }
             } else {
               // with client auth, enable only http1.1 and 2
               // let client_certs_verifier = rustls::server::AllowAnyAnonymousOrAuthenticatedClient::new(client_ca_roots);
@@ -320,7 +331,7 @@ impl Backends {
     }
     #[cfg(not(feature = "http3"))]
     {
-      server_config.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
+      server_crypto_global.alpn_protocols = vec![b"h2".to_vec(), b"http/1.1".to_vec()];
     }
 
     Ok(ServerCrypto {

src/backend/sticky_cookie.rs

@@ -4,14 +4,6 @@ use crate::error::*;
 use chrono::{TimeZone, Utc};
 use derive_builder::Builder;
 
-#[derive(Debug, Clone)]
-/// Struct to handle the sticky cookie string,
-/// - passed from Rp module (http handler) to LB module, manipulated from req, only StickyCookieValue exists.
-/// - passed from LB module to Rp module (http handler), will be inserted into res, StickyCookieValue and Info exist.
-pub struct LbContext {
-  pub sticky_cookie: StickyCookie,
-}
-
 #[derive(Debug, Clone, Builder)]
 /// Cookie value only, used for COOKIE in req
 pub struct StickyCookieValue {

src/backend/upstream.rs

@@ -1,14 +1,13 @@
-use super::{
+#[cfg(feature = "sticky-cookie")]
-  load_balance::{
+use super::load_balance::LbStickyRoundRobinBuilder;
-    load_balance_options as lb_opts, LbRandomBuilder, LbRoundRobinBuilder, LbStickyRoundRobinBuilder, LoadBalance,
+use super::load_balance::{load_balance_options as lb_opts, LbRandomBuilder, LbRoundRobinBuilder, LoadBalance};
-  },
+use super::{BytesName, LbContext, PathNameBytesExp, UpstreamOption};
-  load_balance_sticky_cookie::LbContext,
-  BytesName, PathNameBytesExp, UpstreamOption,
-};
 use crate::log::*;
+#[cfg(feature = "sticky-cookie")]
 use base64::{engine::general_purpose, Engine as _};
 use derive_builder::Builder;
 use rustc_hash::{FxHashMap as HashMap, FxHashSet as HashSet};
+#[cfg(feature = "sticky-cookie")]
 use sha2::{Digest, Sha256};
 use std::borrow::Cow;
 #[derive(Debug, Clone)]
@@ -58,6 +57,7 @@ pub struct Upstream {
   pub uri: hyper::Uri,
 }
 impl Upstream {
+  #[cfg(feature = "sticky-cookie")]
   /// Hashing uri with index to avoid collision
   pub fn calculate_id_with_index(&self, index: usize) -> String {
     let mut hasher = Sha256::new();
@@ -114,8 +114,8 @@ impl UpstreamGroupBuilder {
     v: &Option<String>,
     // upstream_num: &usize,
     upstream_vec: &Vec<Upstream>,
-    server_name: &str,
+    _server_name: &str,
-    path_opt: &Option<String>,
+    _path_opt: &Option<String>,
   ) -> &mut Self {
     let upstream_num = &upstream_vec.len();
     let lb = if let Some(x) = v {
@@ -128,10 +128,11 @@ impl UpstreamGroupBuilder {
             .build()
             .unwrap(),
         ),
+        #[cfg(feature = "sticky-cookie")]
         lb_opts::STICKY_ROUND_ROBIN => LoadBalance::StickyRoundRobin(
           LbStickyRoundRobinBuilder::default()
             .num_upstreams(upstream_num)
-            .sticky_config(server_name, path_opt)
+            .sticky_config(_server_name, _path_opt)
             .upstream_maps(upstream_vec) // TODO:
             .build()
             .unwrap(),
@@ -180,7 +181,10 @@ impl UpstreamGroup {
 
 #[cfg(test)]
 mod test {
+  #[allow(unused)]
   use super::*;
+
+  #[cfg(feature = "sticky-cookie")]
   #[test]
   fn calc_id_works() {
     let uri = "https://www.rust-lang.org".parse::<hyper::Uri>().unwrap();

src/constants.rs

@@ -25,5 +25,6 @@ pub mod H3 {
   pub const MAX_IDLE_TIMEOUT: u64 = 10; // secs
 }
 
-// For load-balancing with sticky cookie
+#[cfg(feature = "sticky-cookie")]
+/// For load-balancing with sticky cookie
 pub const STICKY_COOKIE_NAME: &str = "rpxy_srv_id";

src/error.rs

@@ -22,15 +22,18 @@ pub enum RpxyError {
   #[error("TCP/UDP Proxy Layer Error: {0}")]
   Proxy(String),
 
+  #[allow(unused)]
   #[error("LoadBalance Layer Error: {0}")]
   LoadBalance(String),
 
   #[error("I/O Error")]
   Io(#[from] io::Error),
 
+  #[cfg(feature = "http3")]
   #[error("Quic Connection Error")]
   QuicConn(#[from] quinn::ConnectionError),
 
+  #[cfg(feature = "http3")]
   #[error("H3 Error")]
   H3(#[from] h3::Error),
 

src/handler/handler_main.rs

@@ -1,7 +1,7 @@
 // Highly motivated by https://github.com/felipenoris/hyper-reverse-proxy
 use super::{utils_headers::*, utils_request::*, utils_synth_response::*, HandlerContext};
 use crate::{
-  backend::{Backend, LoadBalance, UpstreamGroup},
+  backend::{Backend, UpstreamGroup},
   error::*,
   globals::Globals,
   log::*,
@@ -91,7 +91,7 @@ where
     let request_upgraded = req.extensions_mut().remove::<hyper::upgrade::OnUpgrade>();
 
     // Build request from destination information
-    let context = match self.generate_request_forwarded(
+    let _context = match self.generate_request_forwarded(
       &client_addr,
       &listen_addr,
       &mut req,
@@ -127,7 +127,8 @@ where
     };
 
     // Process reverse proxy context generated during the forwarding request generation.
-    if let Some(context_from_lb) = context.context_lb {
+    #[cfg(feature = "sticky-cookie")]
+    if let Some(context_from_lb) = _context.context_lb {
       let res_headers = res_backend.headers_mut();
       if let Err(e) = set_sticky_cookie_lb_context(res_headers, &context_from_lb) {
         error!("Failed to append context to the response given from backend: {}", e);
@@ -279,15 +280,24 @@ where
 
     /////////////////////////////////////////////
     // Fix unique upstream destination since there could be multiple ones.
-    let context_to_lb = if let LoadBalance::StickyRoundRobin(lb) = &upstream_group.lb {
+    #[cfg(feature = "sticky-cookie")]
+    let (upstream_chosen_opt, context_from_lb) = {
+      let context_to_lb = if let crate::backend::LoadBalance::StickyRoundRobin(lb) = &upstream_group.lb {
         takeout_sticky_cookie_lb_context(req.headers_mut(), &lb.sticky_config.name)?
       } else {
         None
       };
-    let (upstream_chosen_opt, context_from_lb) = upstream_group.get(&context_to_lb);
+      upstream_group.get(&context_to_lb)
+    };
+    #[cfg(not(feature = "sticky-cookie"))]
+    let (upstream_chosen_opt, _) = upstream_group.get(&None);
+
     let upstream_chosen = upstream_chosen_opt.ok_or_else(|| anyhow!("Failed to get upstream"))?;
     let context = HandlerContext {
+      #[cfg(feature = "sticky-cookie")]
       context_lb: context_from_lb,
+      #[cfg(not(feature = "sticky-cookie"))]
+      context_lb: None,
     };
     /////////////////////////////////////////////
 

src/handler/mod.rs

@@ -3,11 +3,15 @@ mod utils_headers;
 mod utils_request;
 mod utils_synth_response;
 
+#[cfg(feature = "sticky-cookie")]
+use crate::backend::LbContext;
 pub use handler_main::{HttpMessageHandler, HttpMessageHandlerBuilder, HttpMessageHandlerBuilderError};
 
-use crate::backend::LbContext;
+#[allow(dead_code)]
-
 #[derive(Debug)]
 struct HandlerContext {
+  #[cfg(feature = "sticky-cookie")]
   context_lb: Option<LbContext>,
+  #[cfg(not(feature = "sticky-cookie"))]
+  context_lb: Option<()>,
 }

src/handler/utils_headers.rs

@@ -1,9 +1,8 @@
-use crate::{
+#[cfg(feature = "sticky-cookie")]
-  backend::{LbContext, StickyCookie, StickyCookieValue, UpstreamGroup, UpstreamOption},
+use crate::backend::{LbContext, StickyCookie, StickyCookieValue};
-  error::*,
+use crate::backend::{UpstreamGroup, UpstreamOption};
-  log::*,
+
-  utils::*,
+use crate::{error::*, log::*, utils::*};
-};
 use bytes::BufMut;
 use hyper::{
   header::{self, HeaderMap, HeaderName, HeaderValue},
@@ -14,6 +13,7 @@ use std::net::SocketAddr;
 ////////////////////////////////////////////////////
 // Functions to manipulate headers
 
+#[cfg(feature = "sticky-cookie")]
 /// Take sticky cookie header value from request header,
 /// and returns LbContext to be forwarded to LB if exist and if needed.
 /// Removing sticky cookie is needed and it must not be passed to the upstream.
@@ -55,6 +55,7 @@ pub(super) fn takeout_sticky_cookie_lb_context(
   }
 }
 
+#[cfg(feature = "sticky-cookie")]
 /// Set-Cookie if LB Sticky is enabled and if cookie is newly created/updated.
 /// Set-Cookie response header could be in multiple lines.
 /// https://developer.mozilla.org/ja/docs/Web/HTTP/Headers/Set-Cookie

src/proxy/proxy_tls.rs

@@ -6,10 +6,10 @@ use crate::{
   log::*,
   utils::BytesName,
 };
-#[cfg(feature = "http3")]
 use hyper::{client::connect::Connect, server::conn::Http};
 #[cfg(feature = "http3")]
 use quinn::{crypto::rustls::HandshakeData, Endpoint, ServerConfig as QuicServerConfig, TransportConfig};
+#[cfg(feature = "http3")]
 use rustls::ServerConfig;
 use std::sync::Arc;
 use tokio::{
@@ -196,14 +196,14 @@ where
     let (tx, rx) = watch::channel::<Option<Arc<ServerCrypto>>>(None);
     #[cfg(not(feature = "http3"))]
     {
-      select! {
+      tokio::select! {
-        _= self.cert_service(tx).fuse() => {
+        _= self.cert_service(tx) => {
           error!("Cert service for TLS exited");
         },
-        _ = self.listener_service(server, rx).fuse() => {
+        _ = self.listener_service(server, rx) => {
           error!("TCP proxy service for TLS exited");
         },
-        complete => {
+        else => {
           error!("Something went wrong");
           return Ok(())
         }