Replaces local, fastly backend config with dynamic backends.

Only required config is origin_url.
Origin backend is deprecated.

Author: ChristianPavilonis

crates/common/src/publisher.rs

@@ -1,7 +1,9 @@
 use error_stack::{Report, ResultExt};
 use fastly::http::{header, StatusCode};
 use fastly::{Body, Request, Response};
+use url::Url;
 
+use crate::backend::ensure_origin_backend;
 use crate::http_util::serve_static_with_etag;
 
 use crate::constants::{
@@ -359,17 +361,32 @@ pub fn handle_publisher_request(
         has_synthetic_cookie
     );
 
-    // Extract host from the origin_url using the Publisher's origin_host method
-    let origin_host = settings.publisher.origin_host();
+    let parsed_url =
+        Url::parse(&settings.publisher.origin_url).change_context(TrustedServerError::Proxy {
+            message: format!("Invalid origin_url: {}", settings.publisher.origin_url),
+        })?;
+
+    let scheme = parsed_url.scheme();
+    let origin_host = parsed_url.host_str().ok_or_else(|| {
+        Report::new(TrustedServerError::Proxy {
+            message: "Missing host in origin_url".to_string(),
+        })
+    })?;
+    let port = parsed_url.port();
 
-    log::info!("Setting host header to: {}", origin_host);
-    req.set_header("host", &origin_host);
+    let backend_name = ensure_origin_backend(scheme, origin_host, port)?;
+
+    log::info!(
+        "Proxying to dynamic backend: {} (from {})",
+        backend_name,
+        settings.publisher.origin_url
+    );
+    req.set_header("host", origin_host);
 
-    // Send the request to the origin backend
     let mut response = req
-        .send(&settings.publisher.origin_backend)
+        .send(&backend_name)
         .change_context(TrustedServerError::Proxy {
-            message: "Failed to proxy request".to_string(),
+            message: "Failed to proxy request to origin".to_string(),
         })?;
 
     // Log all response headers for debugging

crates/common/src/settings.rs

@@ -21,6 +21,7 @@ pub struct AdServer {
 pub struct Publisher {
     pub domain: String,
     pub cookie_domain: String,
+    #[deprecated(note = "Use origin_url instead - dynamic backends are created automatically")]
     pub origin_backend: String,
     pub origin_url: String,
     /// Secret used to encrypt/decrypt proxied URLs in `/first-party/proxy`.

fastly.toml

@@ -67,10 +67,6 @@ build = """
         [local_server.backends.googleads_doubleclick_backend]
             url = "https://securepubads.g.doubleclick.net"
 
-        [local_server.backends.publisher_origin]
-            url = "http://localhost:9090"
-            override_host = "localhost:9090"
-        
         # Backend for proxying ad creatives and tracking pixels
         [local_server.backends.ad_cdn_backend]
             url = "https://cdn.adsrvr.org"  # Default, will be overridden dynamically

trusted-server.toml

@@ -5,6 +5,7 @@ sync_url = "https://adapi-srv-eu.smartadserver.com/ac?pgid=2040327&fmtid=137675&
 [publisher]
 domain = "test-publisher.com"
 cookie_domain = ".test-publisher.com"
+# DEPRECATED origin backend is now dynamically created
 origin_backend = "publisher_origin"
 origin_url = "https://origin.test-publisher.com"
 proxy_secret = "change-me-proxy-secret"