fix(ilm): harden signer failures and guard remote tier delete storms (#2706)

crates/ecstore/src/client/signer_error.rs

@@ -0,0 +1,74 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::error::Error as StdError;
+use std::fmt::{Display, Formatter};
+use std::io::{Error, ErrorKind};
+
+pub(crate) const SIGNER_HEADER_ERROR_MARKER: &str = "rustfs_signer_header_error";
+
+#[derive(Debug)]
+struct SignerHeaderError {
+    scope: String,
+    header_name: String,
+}
+
+impl SignerHeaderError {
+    fn new(scope: &str, header_name: &str) -> Self {
+        Self {
+            scope: scope.to_string(),
+            header_name: header_name.to_string(),
+        }
+    }
+}
+
+impl Display for SignerHeaderError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}: invalid UTF-8 header value for `{}` [{}]",
+            self.scope, self.header_name, SIGNER_HEADER_ERROR_MARKER
+        )
+    }
+}
+
+impl StdError for SignerHeaderError {}
+
+pub(crate) fn invalid_utf8_header_error(scope: &str, header_name: &str) -> Error {
+    Error::new(ErrorKind::InvalidInput, SignerHeaderError::new(scope, header_name))
+}
+
+pub(crate) fn signer_error_to_io_error(scope: &str, error: rustfs_signer::SignV4Error) -> Error {
+    match error {
+        rustfs_signer::SignV4Error::InvalidHeaderValue { name } => invalid_utf8_header_error(scope, &name),
+        other => Error::other(format!("{scope}: {other}")),
+    }
+}
+
+pub(crate) fn error_chain_contains_signer_header_marker(err: &(dyn StdError + 'static)) -> bool {
+    let mut current = Some(err);
+    while let Some(source) = current {
+        if source.downcast_ref::<SignerHeaderError>().is_some() {
+            return true;
+        }
+
+        if source.to_string().contains(SIGNER_HEADER_ERROR_MARKER) {
+            return true;
+        }
+
+        current = source.source();
+    }
+
+    false
+}