composepost: Drop rpmdb sqlite journaling files

See rpm-software-management/rpm#2219
This is one of the things that makes builds unreproducible in
general, which is worth fixing alone.

But the thing immediately driving this now for me is that I
think we're getting some ill-defined behavior because we
may have these files hardlinked (via ostree) and depending
on the container build environment, we may or may not see
modifications "through" the hardlink:
https://docs.kernel.org/filesystems/overlayfs.html#index

If we happen to mutate the `rpmdb.sqlite-shm` file in
one path but not the other confusion could easily result.

(Actually what we want to do really is drop our other
 hardlinked copies of the rpmdb entirely, but that's
 a bigger change)

Signed-off-by: Colin Walters <[email protected]>

Cargo.toml

@@ -79,6 +79,7 @@ phf = { version = "0.11", features = ["macros"] }
 rand = "0.8.5"
 rayon = "1.10.0"
 regex = "1.10"
+rusqlite = "0.32.1"
 reqwest = { version = "0.12", features = ["native-tls", "blocking", "gzip"] }
 rpmostree-client = { path = "rust/rpmostree-client", version = "0.1.0" }
 rust-ini = "0.21.1"

rust/src/composepost.rs

@@ -421,6 +421,17 @@ fn postprocess_cleanup_rpmdb_impl(rootfs_dfd: &Dir) -> Result<()> {
     } else {
         return Ok(());
     };
+    // https://github.com/rpm-software-management/rpm/issues/2219
+    const RPMDB_SQLITE: &str = "rpmdb.sqlite";
+    const RPMDB_SQLITE_SHM: &str = "rpmdb.sqlite-shm";
+    if d.try_exists(RPMDB_SQLITE_SHM)? {
+        tracing::debug!("Cleaning up {RPMDB_SQLITE_SHM}");
+        let procpath = format!("/proc/self/fd/{}/{RPMDB_SQLITE}", d.as_raw_fd());
+        let conn = rusqlite::Connection::open(&procpath)
+            .with_context(|| format!("Opening {RPMDB_SQLITE}"))?;
+        conn.pragma_update(None, "journal_mode", "DELETE")?;
+        conn.close().map_err(|r| r.1)?;
+    }
     for ent in d.entries()? {
         let ent = ent?;
         let name = ent.file_name()?;
@@ -1184,6 +1195,8 @@ fn rewrite_rpmdb_for_target_inner(rootfs_dfd: &Dir, normalize: bool) -> Result<(
         normalization::normalize_rpmdb(rootfs_dfd, RPMOSTREE_RPMDB_LOCATION)?;
     }
 
+    postprocess_cleanup_rpmdb_impl(rootfs_dfd)?;
+
     tempetc.undo()?;
 
     Ok(())

tests/compose/libbasic-test.sh

@@ -43,6 +43,7 @@ echo "ok etc/default/useradd"
 for path in /usr/share/rpm /usr/lib/sysimage/rpm-ostree-base-db; do
     ostree --repo=${repo} ls -R ${treeref} ${path} > db.txt
     assert_file_has_content_literal db.txt rpmdb.sqlite
+    assert_not_file_has_content db.txt rpmdb.sqlite-shm
 done
 ostree --repo=${repo} ls ${treeref} /usr/lib/sysimage/rpm >/dev/null
 echo "ok db"