Fix lint to check /etc/tmpfiles.d

The bootc container lint command now reads tmpfiles.d configuration files
from both /usr/lib/tmpfiles.d and /etc/tmpfiles.d, with /etc entries
taking precedence (matching systemd's behavior).

Fixes #1732

Signed-off-by: gursewak1997 <[email protected]>

Author: gursewak1997

crates/tmpfiles/src/lib.rs

@@ -20,6 +20,7 @@ use rustix::path::Arg;
 use thiserror::Error;
 
 const TMPFILESD: &str = "usr/lib/tmpfiles.d";
+const ETC_TMPFILESD: &str = "etc/tmpfiles.d";
 /// The path to the file we use for generation
 const BOOTC_GENERATED_PREFIX: &str = "bootc-autogenerated-var";
 
@@ -452,14 +453,16 @@ pub fn find_missing_tmpfiles_current_root() -> Result<TmpfilesResult> {
     })
 }
 
-/// Read all tmpfiles.d entries in the target directory, and return a mapping
-/// from (file path) => (single tmpfiles.d entry line)
-fn read_tmpfiles(rootfs: &Dir) -> Result<(BTreeMap<PathBuf, String>, BootcTmpfilesGeneration)> {
-    let Some(tmpfiles_dir) = rootfs.open_dir_optional(TMPFILESD)? else {
+/// Read all tmpfiles.d entries from a single directory
+fn read_tmpfiles_from_dir(
+    rootfs: &Dir,
+    dir_path: &str,
+    generation: &mut BootcTmpfilesGeneration,
+) -> Result<BTreeMap<PathBuf, String>> {
+    let Some(tmpfiles_dir) = rootfs.open_dir_optional(dir_path)? else {
         return Ok(Default::default());
     };
     let mut result = BTreeMap::new();
-    let mut generation = BootcTmpfilesGeneration::default();
     for entry in tmpfiles_dir.entries()? {
         let entry = entry?;
         let name = entry.file_name();
@@ -486,6 +489,25 @@ fn read_tmpfiles(rootfs: &Dir) -> Result<(BTreeMap<PathBuf, String>, BootcTmpfil
             result.insert(path.to_owned(), line);
         }
     }
+    Ok(result)
+}
+
+/// Read all tmpfiles.d entries in the target directory, and return a mapping
+/// from (file path) => (single tmpfiles.d entry line)
+///
+/// This function reads from both `/usr/lib/tmpfiles.d` and `/etc/tmpfiles.d`,
+/// with `/etc` entries taking precedence (matching systemd's behavior).
+fn read_tmpfiles(rootfs: &Dir) -> Result<(BTreeMap<PathBuf, String>, BootcTmpfilesGeneration)> {
+    let mut generation = BootcTmpfilesGeneration::default();
+
+    // Read from /usr/lib/tmpfiles.d first (system/package-provided)
+    let mut result = read_tmpfiles_from_dir(rootfs, TMPFILESD, &mut generation)?;
+
+    // Read from /etc/tmpfiles.d and merge (user-provided, takes precedence)
+    let etc_result = read_tmpfiles_from_dir(rootfs, ETC_TMPFILESD, &mut generation)?;
+    // /etc entries override /usr/lib entries for the same path
+    result.extend(etc_result);
+
     Ok((result, generation))
 }
 
@@ -569,10 +591,18 @@ mod tests {
         "#},
         )?;
 
+        // Also test /etc/tmpfiles.d (user-provided configs)
+        rootfs.create_dir_all(ETC_TMPFILESD)?;
+        rootfs.write(
+            Path::new(ETC_TMPFILESD).join("user.conf"),
+            "d /var/lib/user 0755 root root - -\n",
+        )?;
+
         // Add test content.
         rootfs.ensure_dir_with("var/lib/systemd", &db)?;
         rootfs.ensure_dir_with("var/lib/private", &db)?;
         rootfs.ensure_dir_with("var/lib/nfs", &db)?;
+        rootfs.ensure_dir_with("var/lib/user", &db)?;
         let global_rwx = Permissions::from_mode(0o777);
         rootfs.ensure_dir_with("var/lib/test/nested", &db).unwrap();
         rootfs.set_permissions("var/lib/test", global_rwx.clone())?;