From edb797da6877c1f9d71407175f3188a82ff29a5b Mon Sep 17 00:00:00 2001
From: durch <durch@users.noreply.github.com>
Date: Mon, 1 Sep 2025 12:25:25 +0200
Subject: [PATCH] Explicit warning on missing fronting configuration

---
 Cargo.toml                        |  1 +
 common/http-api-client/Cargo.toml |  4 +--
 common/http-api-client/src/lib.rs | 41 +++++++++++++++++--------------
 3 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 06a754e579..9d8a3b7cf4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -318,6 +318,7 @@ serde_json_path = "0.7.2"
 serde_repr = "0.1"
 serde_with = "3.9.0"
 serde_yaml = "0.9.25"
+serde_plain = "1.0.2"
 sha2 = "0.10.9"
 si-scale = "0.2.3"
 snow = "0.9.6"
diff --git a/common/http-api-client/Cargo.toml b/common/http-api-client/Cargo.toml
index 3719960aef..66c0f94695 100644
--- a/common/http-api-client/Cargo.toml
+++ b/common/http-api-client/Cargo.toml
@@ -24,8 +24,8 @@ url = { workspace = true }
 once_cell = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-serde_yaml = "0.9.34-deprecated"
-serde_plain = "1.0.2"
+serde_yaml = { workspace = true}
+serde_plain = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 itertools = { workspace = true }
diff --git a/common/http-api-client/src/lib.rs b/common/http-api-client/src/lib.rs
index 57f78e8b74..9004480734 100644
--- a/common/http-api-client/src/lib.rs
+++ b/common/http-api-client/src/lib.rs
@@ -802,27 +802,32 @@ impl Client {
         #[cfg(feature = "tunneling")]
         if let Some(ref front) = self.front {
             if front.is_enabled() {
-                let front_host = url.front_str().unwrap_or("");
-                let actual_host = url.host_str().unwrap_or("");
+                if let Some(front_host) = url.front_str() {
+                    if let Some(actual_host) = url.host_str() {
+                        tracing::debug!(
+                            "Domain fronting enabled: routing via CDN {} to actual host {}",
+                            front_host,
+                            actual_host
+                        );
 
-                tracing::debug!(
-                    "Domain fronting enabled: routing via CDN {} to actual host {}",
-                    front_host,
-                    actual_host
-                );
+                        // this should never fail as we are transplanting the host from one url to another
+                        r.url_mut().set_host(Some(front_host)).unwrap();
 
-                // this should never fail as we are transplanting the host from one url to another
-                r.url_mut().set_host(Some(front_host)).unwrap();
+                        let actual_host_header: HeaderValue =
+                            actual_host.parse().unwrap_or(HeaderValue::from_static(""));
+                        // If the map did have this key present, the new value is associated with the key
+                        // and all previous values are removed. (reqwest HeaderMap docs)
+                        _ = r
+                            .headers_mut()
+                            .insert(reqwest::header::HOST, actual_host_header);
 
-                let actual_host_header: HeaderValue =
-                    actual_host.parse().unwrap_or(HeaderValue::from_static(""));
-                // If the map did have this key present, the new value is associated with the key
-                // and all previous values are removed. (reqwest HeaderMap docs)
-                _ = r
-                    .headers_mut()
-                    .insert(reqwest::header::HOST, actual_host_header);
-
-                return (url.as_str(), url.front_str());
+                        return (url.as_str(), url.front_str());
+                    } else {
+                        warn!("Domain fronting is enabled, but no host_url is defined! Domain fronting WILL NOT WORK")
+                    }
+                } else {
+                    warn!("Domain fronting is enabled, but no front_url is defined! Domain fronting WILL NOT WORK")
+                }
             }
         }
         (url.as_str(), None)