return proper 404 when layer not found

crates/rattler_networking/Cargo.toml

@@ -21,7 +21,7 @@ async-trait = { workspace = true }
 base64 = { workspace = true }
 dirs = { workspace = true }
 fslock = { workspace = true }
-http = "1.1.0"
+http = "0.2"
 itertools = { workspace = true }
 keyring = { workspace = true }
 lazy_static = { workspace = true }

crates/rattler_networking/src/mirror_middleware.rs

@@ -7,19 +7,32 @@ use std::{
     },
 };
 
+use http::StatusCode;
 use reqwest::{
     header::{ACCEPT, AUTHORIZATION},
-    Request, Response,
+    Request, Response, ResponseBuilderExt,
 };
 use reqwest_middleware::{Middleware, Next, Result};
 use serde::Deserialize;
 use task_local_extensions::Extensions;
 use url::Url;
 
+#[allow(dead_code)]
+/// Settings for the specific mirror (e.g. no zstd or bz2 support)
+struct MirrorSettings {
+    no_zstd: bool,
+    no_bz2: bool,
+    no_gz: bool,
+    max_failures: Option<usize>,
+}
+
+#[allow(dead_code)]
 struct MirrorState {
     url: Url,
 
     failures: AtomicUsize,
+
+    settings: MirrorSettings,
 }
 
 impl MirrorState {
@@ -50,6 +63,12 @@ impl MirrorMiddleware {
                         MirrorState {
                             url: Url::parse(&url).unwrap(),
                             failures: AtomicUsize::new(0),
+                            settings: MirrorSettings {
+                                no_zstd: false,
+                                no_bz2: false,
+                                no_gz: false,
+                                max_failures: Some(3),
+                            },
                         }
                     })
                     .collect();
@@ -139,6 +158,16 @@ struct OCIToken {
     token: String,
 }
 
+pub(crate) fn create_404_response(url: &Url, body: &str) -> Response {
+    Response::from(
+        http::response::Builder::new()
+            .status(StatusCode::NOT_FOUND)
+            .url(url.clone())
+            .body(body.to_string())
+            .unwrap(),
+    )
+}
+
 // [oci://ghcr.io/channel-mirrors/conda-forge]/[osx-arm64/xtensor]
 async fn get_token(url: &Url, action: OciAction) -> Result<String> {
     let token_url: String = format!(
@@ -186,9 +215,9 @@ fn reverse_version_build_tag(tag: &str) -> String {
 }
 
 fn version_build_tag(tag: &str) -> String {
-    tag.replace("+", "__p__")
-        .replace("!", "__e__")
-        .replace("=", "__eq__")
+    tag.replace('+', "__p__")
+        .replace('!', "__e__")
+        .replace('=', "__eq__")
 }
 
 /// We reimplement some logic from rattler here because we don't want to introduce cyclic dependencies
@@ -227,7 +256,7 @@ fn package_to_tag(url: &Url) -> OciTagMediaType {
         }
     }
 
-    if computed_filename.starts_with("_") {
+    if computed_filename.starts_with('_') {
         computed_filename = format!("zzz{computed_filename}");
     }
 
@@ -276,7 +305,7 @@ impl Middleware for OciMiddleware {
         let token = if let Some(token) = token {
             token
         } else {
-            let token = get_token(&url, OciAction::Pull).await?;
+            let token = get_token(url, OciAction::Pull).await?;
             self.token_cache
                 .lock()
                 .unwrap()
@@ -295,7 +324,7 @@ impl Middleware for OciMiddleware {
             .get("X-ExpectedSha256")
             .map(|s| s.to_str().unwrap().to_string())
         {
-            *req.url_mut() = oci_url_with_hash(&url, &expected_sha_hash);
+            *req.url_mut() = oci_url_with_hash(url, &expected_sha_hash);
             next.run(req, extensions).await
         } else {
             // get the tag from the URL
@@ -315,11 +344,7 @@ impl Middleware for OciMiddleware {
                 .await
                 .map_err(reqwest_middleware::Error::Reqwest)?;
 
-            let manifest_string = manifest.text().await?;
-            tracing::info!("{}", manifest_string);
-            let manifest: Manifest = serde_json::from_str(&manifest_string).unwrap();
-
-            tracing::info!("{:?}", oci_info);
+            let manifest: Manifest = manifest.json().await?;
 
             let layer = if let Some(layer) = manifest
                 .layers
@@ -328,10 +353,10 @@ impl Middleware for OciMiddleware {
             {
                 layer
             } else {
-                // TODO it would be much better to return a 404 here
-                return Err(reqwest_middleware::Error::Middleware(anyhow::anyhow!(
-                    "No layer found with the expected media type".to_string()
-                )));
+                return Ok(create_404_response(
+                    url,
+                    "No layer available for media type",
+                ));
             };
 
             let layer_url = format!(