From 91dce87c88e24a828f5dac83c630e7b50de29b80 Mon Sep 17 00:00:00 2001
From: Brian Picciano <mediocregopher@gmail.com>
Date: Wed, 19 Jul 2023 16:18:13 +0200
Subject: [PATCH] Add add/remove_path_prefix fields to domain settings

---
 src/domain/manager.rs  |  7 ++++++-
 src/domain/settings.rs | 24 ++++++++++++++++++++++++
 src/domain/store.rs    |  4 ++++
 src/origin/proxy.rs    |  6 +++---
 src/service/util.rs    |  6 +++++-
 5 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/src/domain/manager.rs b/src/domain/manager.rs
index c8e499c..e2ce452 100644
--- a/src/domain/manager.rs
+++ b/src/domain/manager.rs
@@ -252,7 +252,12 @@ impl Manager for ManagerImpl {
             return Err(unexpected::Error::from("origin is proxy, can't serve file").into());
         }
 
-        let f = self.origin_store.get_file(&settings.origin_descr, path)?;
+        let path = settings.process_path(path);
+
+        let f = self
+            .origin_store
+            .get_file(&settings.origin_descr, path.as_ref())?;
+
         Ok(f)
     }
 
diff --git a/src/domain/settings.rs b/src/domain/settings.rs
index 791d95d..f02c0dd 100644
--- a/src/domain/settings.rs
+++ b/src/domain/settings.rs
@@ -1,6 +1,8 @@
 use crate::error::unexpected::{self, Mappable};
 use crate::origin;
 
+use std::borrow;
+
 use hex::ToHex;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
@@ -11,6 +13,9 @@ use sha2::{Digest, Sha256};
 pub struct Settings {
     #[serde(flatten)]
     pub origin_descr: origin::Descr,
+
+    pub remove_path_prefix: Option<String>,
+    pub add_path_prefix: Option<String>,
 }
 
 impl Settings {
@@ -19,4 +24,23 @@ impl Settings {
         serde_json::to_writer(&mut h, self).or_unexpected()?;
         Ok(h.finalize().encode_hex::<String>())
     }
+
+    pub fn process_path<'a>(&self, path: &'a str) -> borrow::Cow<'a, str> {
+        let mut path = borrow::Cow::Borrowed(path);
+
+        if let Some(ref remove_path_prefix) = self.remove_path_prefix {
+            if path.starts_with(remove_path_prefix.as_str()) {
+                *path.to_mut() = path.strip_prefix(remove_path_prefix).unwrap().to_string();
+            }
+        }
+
+        if let Some(ref add_path_prefix) = self.add_path_prefix {
+            let mut prefixed_path = String::with_capacity(add_path_prefix.len() + path.len());
+            prefixed_path.push_str(add_path_prefix);
+            prefixed_path.push_str(path.as_ref());
+            *path.to_mut() = prefixed_path;
+        }
+
+        path
+    }
 }
diff --git a/src/domain/store.rs b/src/domain/store.rs
index efe3a68..bc0297f 100644
--- a/src/domain/store.rs
+++ b/src/domain/store.rs
@@ -181,6 +181,8 @@ mod tests {
                 url: "bar".to_string(),
                 branch_name: "baz".to_string(),
             },
+            remove_path_prefix: None,
+            add_path_prefix: None,
         };
 
         assert!(matches!(
@@ -203,6 +205,8 @@ mod tests {
                 url: "BAR".to_string(),
                 branch_name: "BAZ".to_string(),
             },
+            remove_path_prefix: None,
+            add_path_prefix: None,
         };
 
         store.set(&domain, &new_settings).expect("set");
diff --git a/src/origin/proxy.rs b/src/origin/proxy.rs
index 9f6ac8c..057fa4a 100644
--- a/src/origin/proxy.rs
+++ b/src/origin/proxy.rs
@@ -30,7 +30,7 @@ pub async fn serve_http_request(
     mut req: hyper::Request<hyper::Body>,
     req_is_https: bool,
 ) -> unexpected::Result<hyper::Response<hyper::Body>> {
-    let (proxy_url, request_http_headers) = if let origin::Descr::Proxy {
+    let (url, request_http_headers) = if let origin::Descr::Proxy {
         ref url,
         ref request_http_headers,
     } = settings.origin_descr
@@ -67,12 +67,12 @@ pub async fn serve_http_request(
             .insert("x-forwarded-proto", HeaderValue::from_static("https"));
     }
 
-    match hyper_reverse_proxy::call(client_ip, proxy_url, req).await {
+    match hyper_reverse_proxy::call(client_ip, url, req).await {
         Ok(res) => Ok(res),
         // ProxyError doesn't actually implement Error :facepalm: so we have to format the error
         // manually
         Err(e) => Err(unexpected::Error::from(
-            format!("error while proxying to {proxy_url}: {e:?}").as_str(),
+            format!("error while proxying to {url}: {e:?}").as_str(),
         )),
     }
 }
diff --git a/src/service/util.rs b/src/service/util.rs
index e4eec2f..624d2d7 100644
--- a/src/service/util.rs
+++ b/src/service/util.rs
@@ -31,7 +31,11 @@ impl TryFrom<FlatDomainSettings> for domain::Settings {
             _ => Err("invalid domain_setting_origin_descr_kind".to_string()),
         }?;
 
-        Ok(Self { origin_descr })
+        Ok(Self {
+            origin_descr,
+            remove_path_prefix: None,
+            add_path_prefix: None,
+        })
     }
 }