fix(update): keep read-only official plugin files during extract (#595)

* fix(update): keep read-only official plugin files during extract

Docker Desktop returns EPERM when chmod runs again on an official plugin file that tar already unpacked as mode 0444.

Fixes #594

* test(update): cover writable official plugin archives

Co-authored-by: Codex <noreply@openai.com>

---------

Co-authored-by: le-czs <243511553+le-czs@users.noreply.github.com>
Co-authored-by: Zyy <zyycn@users.noreply.github.com>
Co-authored-by: Codex <noreply@openai.com>

backend/crates/gateway-host/src/system_update/archive.rs

@@ -86,11 +86,7 @@ pub(crate) fn extract_release(
                 .unpack(&target)
                 .map_err(|error| internal("无法解压官方插件文件").with_source(error))?;
             #[cfg(unix)]
-            {
-                use std::os::unix::fs::PermissionsExt as _;
-                fs::set_permissions(&target, fs::Permissions::from_mode(0o444))
-                    .map_err(|error| internal("无法设置官方插件文件权限").with_source(error))?;
-            }
+            ensure_official_plugin_file_readonly(&target)?;
             found_official_manifest |= relative == Path::new("plugin-release-manifest.json");
             continue;
         }
@@ -128,6 +124,24 @@ pub(crate) fn extract_release(
     })
 }
 
+#[cfg(unix)]
+fn ensure_official_plugin_file_readonly(path: &Path) -> Result<(), OperationError> {
+    use std::os::unix::fs::PermissionsExt as _;
+
+    // tar 解包已对打开的文件描述符套用归档模式
+    // Docker Desktop 把 macOS 目录挂进容器后，0444 文件再次 chmod 会返回 EPERM，权限已满足时不必再改
+    let current_mode = fs::symlink_metadata(path)
+        .map_err(|error| internal("无法设置官方插件文件权限").with_source(error))?
+        .permissions()
+        .mode()
+        & 0o777;
+    if current_mode == 0o444 {
+        return Ok(());
+    }
+    fs::set_permissions(path, fs::Permissions::from_mode(0o444))
+        .map_err(|error| internal("无法设置官方插件文件权限").with_source(error))
+}
+
 fn unsafe_archive_path(path: &Path) -> bool {
     path.is_absolute()
         || path.components().any(|component| match component {

backend/crates/gateway-host/tests/system_update/mod.rs

@@ -419,13 +419,14 @@ enum ChecksumKind {
 fn release_archive(kind: ArchiveKind) -> Vec<u8> {
     let encoder = GzEncoder::new(Vec::new(), Compression::default());
     let mut tar = Builder::new(encoder);
-    append_file(&mut tar, BINARY_NAME, b"new-binary", false);
-    append_file(&mut tar, "web/dist/index.html", b"new-web", false);
+    append_file(&mut tar, BINARY_NAME, b"new-binary", 0o755, false);
+    append_file(&mut tar, "web/dist/index.html", b"new-web", 0o755, false);
     if !matches!(kind, ArchiveKind::MissingOfficialManifest) {
         append_file(
             &mut tar,
             "plugins/official/plugin-release-manifest.json",
             b"new-manifest",
+            0o444,
             false,
         );
     }
@@ -433,16 +434,18 @@ fn release_archive(kind: ArchiveKind) -> Vec<u8> {
         &mut tar,
         "plugins/official/new-plugin.tar.gz",
         b"new-plugin",
+        0o644,
         false,
     );
     if let ArchiveKind::UnsafePath(name) = kind {
-        append_file(&mut tar, name, b"escape", true);
+        append_file(&mut tar, name, b"escape", 0o755, true);
     }
     if matches!(kind, ArchiveKind::NestedOfficialAsset) {
         append_file(
             &mut tar,
             "plugins/official/nested/plugin.tar.gz",
             b"nested",
+            0o444,
             false,
         );
     }
@@ -468,14 +471,16 @@ fn append_symlink(tar: &mut Builder<GzEncoder<Vec<u8>>>, name: &str, target: &st
     tar.append(&header, std::io::empty()).expect("append link");
 }
 
-fn append_file(tar: &mut Builder<GzEncoder<Vec<u8>>>, name: &str, data: &[u8], unsafe_path: bool) {
+fn append_file(
+    tar: &mut Builder<GzEncoder<Vec<u8>>>,
+    name: &str,
+    data: &[u8],
+    mode: u32,
+    unsafe_path: bool,
+) {
     let mut header = Header::new_gnu();
     header.set_entry_type(EntryType::Regular);
-    header.set_mode(if name.starts_with("plugins/official/") {
-        0o444
-    } else {
-        0o755
-    });
+    header.set_mode(mode);
     header.set_size(u64::try_from(data.len()).expect("size"));
     header
         .set_path(if unsafe_path { "safe" } else { name })

backend/crates/gateway-host/tests/system_update/operations.rs

@@ -471,6 +471,17 @@ async fn rollback_should_restore_binary_web_and_version_state() {
                 & 0o777,
             0o555
         );
+        for name in ["plugin-release-manifest.json", "new-plugin.tar.gz"] {
+            assert_eq!(
+                fs::metadata(fixture.official().join(name))
+                    .expect("official plugin file")
+                    .permissions()
+                    .mode()
+                    & 0o777,
+                0o444,
+                "{name}"
+            );
+        }
     }
     service
         .rollback(Arc::new(AllowingUpdatePreflight))