Implement override checking to make sure we've got the data we need in the layers_dir

src/main.rs

@@ -53,10 +53,18 @@ fn load_settings() -> config::Config {
 #[derive(Clone, Debug)]
 struct AppState {
     conf: config::Config,
-    upstream: String,
 }
 
 impl AppState {
+    /**
+     * Helper f unction for fishing out the upstream registry URL
+     */
+    fn upstream(&self) -> String {
+        self.conf.get_str("registry")
+            .expect("`registry` not properly configured, must be a string")
+    }
+
+
     /**
      * This function returns a true if the configured `layers_dir` has an override
      * for the given triplet of org/image:digest
@@ -64,15 +72,14 @@ impl AppState {
      * For example, if we have a `<layers_dir>/library/alpine/latest/` directory
      * with `*.tar.gz` files within it, then the function would return true.
      */
-    fn override_exists(&self, org: String, image: String, digest: String) -> bool {
+    fn override_exists(&self, org: &str, image: &str, digest: &str) -> bool {
         let layers_dir = self.conf.get_str("layers_dir")
             .expect("Unable to access `layers_dir` conf variable");
 
         info!("Looking in directory: {}", layers_dir);
-        let layers_dir = Path::new(&layers_dir);
+        let path = Path::new(&layers_dir).join(org).join(image).join(digest);
 
-
-        return false;
+        path.exists()
     }
 }
 
@@ -81,7 +88,7 @@ impl AppState {
  * back to the client request it.
  */
 async fn proxy_upstream(req: Request<AppState>) -> Result<Response, tide::Error> {
-    let full_url = format!("{}{}", req.state().upstream, req.url().path());
+    let full_url = format!("{}{}", req.state().upstream(), req.url().path());
     info!("Proxying request upstream to {}", full_url);
      /*
       * We need to send the Authorization header along as well, otherwise
@@ -137,7 +144,8 @@ async fn fetch_digest(req: Request<AppState>) -> Result<Response, tide::Error> {
     let org: String = req.param("org").unwrap_or("".to_string());
     let image: String = req.param("image").unwrap_or("".to_string());
     let digest: String = req.param("digest").unwrap_or("".to_string());
-    if req.state().override_exists(org, image, digest) {
+
+    if req.state().override_exists(&org, &image, &digest) {
         error!("We should not proxy");
         Ok(Response::new(200))
     }
@@ -186,7 +194,6 @@ fn main() -> Result<(), std::io::Error> {
 
     let state = AppState {
         conf: conf,
-        upstream: upstream_url,
     };
 
     task::block_on(async {
@@ -231,4 +238,19 @@ mod tests {
         let result = checksum_for(&path);
         assert!(result.is_err());
     }
+
+    #[test]
+    fn override_exists_false() {
+        let conf = load_settings();
+        let state = AppState { conf };
+        assert_eq!(false, state.override_exists("jenkins", "jenkins", "latest"));
+    }
+
+
+    #[test]
+    fn override_exists_true() {
+        let conf = load_settings();
+        let state = AppState { conf };
+        assert!(state.override_exists("library", "alpine", "latest"));
+    }
 }