fix: change set-upstream-host as a default option

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## 0.7.0  (unreleased)
 
 - Breaking: `hyper`-1.0 for both server and client modules.
-- Breaking: Remove `override_host` option in upstream options. Add a reverse option, i.e., `keep_original_host`. That is, `rpxy` always override the host header by the upstream hostname (backend uri host name) by default. If this reverse option specified, original `host` header is maintained or added from the value of url request line.
+- Breaking: Remove `override_host` option in upstream options. Add a reverse option, i.e., `keep_original_host`, and the similar option `set_upstream_host`. While `keep_original_host` can be explicitly specified, `rpxy` keeps the original `host` given by the incoming request by default. Then, the original `host` header is maintained or added from the value of url request line. If `host` header needs to be overridden with the upstream host name (backend uri's host name), `set_upstream_host` has to be set. If both of `set_upstream_host` and `keep_original_host` are set, `keep_original_host` is prioritized since it is explicitly specified.
 - Breaking: Introduced `native-tls-backend` feature to use the native TLS engine to access backend applications.
 - Redesigned: Cache structure is totally redesigned with more memory-efficient way to read from cache file, and more secure way to strongly bind memory-objects with files with hash values.
 - Redesigned: HTTP body handling flow is also redesigned with more memory-and-time efficient techniques without putting the whole objects on memory by using `futures::stream::Stream` and `futures::channel::mpsc`

config-example.toml

@@ -57,7 +57,7 @@ upstream = [
 ]
 load_balance = "round_robin" # or "random" or "sticky" (sticky session) or "none" (fix to the first one, default)
 upstream_options = [
-  "keep_original_host",   # do not overwrite HOST value with upstream hostname (like 192.168.xx.x seen from rpxy)
+  "keep_original_host",   # [default] do not overwrite HOST value with upstream hostname (like 192.168.xx.x seen from rpxy), which is prior to "set_upstream_host" if both are specified.
   "force_http2_upstream", # mutually exclusive with "force_http11_upstream"
 ]
 
@@ -76,9 +76,9 @@ upstream = [
 ]
 load_balance = "random" # or "round_robin" or "sticky" (sticky session) or "none" (fix to the first one, default)
 upstream_options = [
-  "disable_override_host",
   "upgrade_insecure_requests",
   "force_http11_upstream",
+  "set_upstream_host",         # overwrite HOST value with upstream hostname (like www.yahoo.com)
 ]
 ######################################################################
 

rpxy-lib/src/backend/upstream_opts.rs

@@ -1,10 +1,17 @@
 use crate::error::*;
 
+/// Options for request message to be sent to upstream.
 #[derive(Debug, Clone, Hash, Eq, PartialEq)]
 pub enum UpstreamOption {
+  /// Keep original host header, which is prioritized over SetUpstreamHost
   KeepOriginalHost,
+  /// Overwrite host header with upstream hostname
+  SetUpstreamHost,
+  /// Add upgrade-insecure-requests header
   UpgradeInsecureRequests,
+  /// Force HTTP/1.1 upstream
   ForceHttp11Upstream,
+  /// Force HTTP/2 upstream
   ForceHttp2Upstream,
   // TODO: Adds more options for heder override
 }
@@ -13,6 +20,7 @@ impl TryFrom<&str> for UpstreamOption {
   fn try_from(val: &str) -> RpxyResult<Self> {
     match val {
       "keep_original_host" => Ok(Self::KeepOriginalHost),
+      "set_upstream_host" => Ok(Self::SetUpstreamHost),
       "upgrade_insecure_requests" => Ok(Self::UpgradeInsecureRequests),
       "force_http11_upstream" => Ok(Self::ForceHttp11Upstream),
       "force_http2_upstream" => Ok(Self::ForceHttp2Upstream),

rpxy-lib/src/message_handler/handler_manipulate_messages.rs

@@ -99,14 +99,14 @@ where
       headers.insert(header::TE, HeaderValue::from_bytes("trailers".as_bytes()).unwrap());
     }
 
-    // add "host" header of original server_name if not exist (default)
+    // by default, add "host" header of original server_name if not exist
     if req.headers().get(header::HOST).is_none() {
       let org_host = req.uri().host().ok_or_else(|| anyhow!("Invalid request"))?.to_owned();
       req
         .headers_mut()
         .insert(header::HOST, HeaderValue::from_str(&org_host)?);
     };
-    let original_host_header = req.headers().get(header::HOST).unwrap().clone();
+    println!("{:?}", req.headers().get(header::HOST));
 
     /////////////////////////////////////////////
     // Fix unique upstream destination since there could be multiple ones.
@@ -133,10 +133,8 @@ where
 
     // apply upstream-specific headers given in upstream_option
     let headers = req.headers_mut();
-    // by default, host header is overwritten with upstream hostname
-    override_host_header(headers, &upstream_chosen.uri)?;
     // apply upstream options to header
-    apply_upstream_options_to_header(headers, &original_host_header, upstream_candidates)?;
+    apply_upstream_options_to_header(headers, &upstream_chosen.uri, upstream_candidates)?;
 
     // update uri in request
     ensure!(
@@ -182,7 +180,6 @@ where
       update_request_line(req, upstream_chosen, upstream_candidates)?;
     }
 
-
     Ok(context)
   }
 }

rpxy-lib/src/message_handler/utils_headers.rs

@@ -86,8 +86,8 @@ pub(super) fn set_sticky_cookie_lb_context(
   Ok(())
 }
 
-/// default: overwrite HOST value with upstream hostname (like 192.168.xx.x seen from rpxy)
-pub(super) fn override_host_header(headers: &mut HeaderMap, upstream_base_uri: &Uri) -> Result<()> {
+/// overwrite HOST value with upstream hostname (like 192.168.xx.x seen from rpxy)
+fn override_host_header(headers: &mut HeaderMap, upstream_base_uri: &Uri) -> Result<()> {
   let mut upstream_host = upstream_base_uri
     .host()
     .ok_or_else(|| anyhow!("No hostname is given"))?
@@ -105,18 +105,18 @@ pub(super) fn override_host_header(headers: &mut HeaderMap, upstream_base_uri: &
 /// Apply options to request header, which are specified in the configuration
 pub(super) fn apply_upstream_options_to_header(
   headers: &mut HeaderMap,
-  original_host_header: &HeaderValue,
+  upstream_base_uri: &Uri,
   // _client_addr: &SocketAddr,
   upstream: &UpstreamCandidates,
-  // _upstream_base_uri: &Uri,
 ) -> Result<()> {
   for opt in upstream.options.iter() {
     match opt {
-      UpstreamOption::KeepOriginalHost => {
-        // revert hostname
-        headers
-          .insert(header::HOST, original_host_header.to_owned())
-          .ok_or_else(|| anyhow!("Failed to revert host header in keep_original_host option"))?;
+      UpstreamOption::SetUpstreamHost => {
+        // prioritize KeepOriginalHost
+        if !upstream.options.contains(&UpstreamOption::KeepOriginalHost) {
+          // overwrite host header, this removes all the HOST header values
+          override_host_header(headers, upstream_base_uri)?;
+        }
       }
       UpstreamOption::UpgradeInsecureRequests => {
         // add upgrade-insecure-requests in request header if not exist