repo: Create metadata commit in ostree_repo_regenerate_metadata

Rather than creating the `ostree-metadata` commit in the summary
builtin, do it in the new `ostree_repo_regenerate_metadata` API. The
commit contents are unchanged and the commit is generated before the
summary as before. To keep from triggering an extra summary update,
automatic summary updating is disabled in the transaction.

Since the summary builtin was already using the new API, it will
continue to generate the `ostree-metadata` commit when the repo has a
collection ID. However, the `ostree_repo_regenerate_summary` API will
still only generate the summary file as before.

3 files changed, 142 insertions, 4 deletions

diff --git a/src/libostree/ostree-repo-commit.c b/src/libostree/ostree-repo-commit.c
index 51bfd46e..7f668b7d 100644
--- a/src/libostree/ostree-repo-commit.c
+++ b/src/libostree/ostree-repo-commit.c
@@ -4871,3 +4871,72 @@ ostree_repo_transaction_stats_free (OstreeRepoTransactionStats *stats)
 G_DEFINE_BOXED_TYPE(OstreeRepoTransactionStats, ostree_repo_transaction_stats,
                     ostree_repo_transaction_stats_copy,
                     ostree_repo_transaction_stats_free);
+
+
+gboolean
+_ostree_repo_transaction_write_repo_metadata (OstreeRepo    *self,
+                                              GVariant      *additional_metadata,
+                                              char         **out_checksum,
+                                              GCancellable  *cancellable,
+                                              GError       **error)
+{
+  g_assert (self != NULL);
+  g_assert (OSTREE_IS_REPO (self));
+  g_assert (self->in_transaction == TRUE);
+
+  const char *collection_id = ostree_repo_get_collection_id (self);
+  if (collection_id == NULL)
+    return glnx_throw (error, "Repository must have collection ID to write repo metadata");
+
+  OstreeCollectionRef collection_ref = { (gchar *) collection_id,
+                                         (gchar *) OSTREE_REPO_METADATA_REF };
+  g_autofree char *old_checksum = NULL;
+  if (!ostree_repo_resolve_rev (self, OSTREE_REPO_METADATA_REF, TRUE,
+                                &old_checksum, error))
+    return FALSE;
+
+  /* Add bindings to the commit metadata. */
+  g_autoptr(GVariantDict) metadata_dict = g_variant_dict_new (additional_metadata);
+  g_variant_dict_insert (metadata_dict, OSTREE_COMMIT_META_KEY_COLLECTION_BINDING,
+                         "s", collection_ref.collection_id);
+  g_variant_dict_insert_value (metadata_dict, OSTREE_COMMIT_META_KEY_REF_BINDING,
+                               g_variant_new_strv ((const gchar * const *) &collection_ref.ref_name, 1));
+  g_autoptr(GVariant) metadata = g_variant_dict_end (metadata_dict);
+
+  /* Set up an empty mtree. */
+  g_autoptr(OstreeMutableTree) mtree = ostree_mutable_tree_new ();
+
+  glnx_unref_object GFileInfo *fi = g_file_info_new ();
+  g_file_info_set_attribute_uint32 (fi, "unix::uid", 0);
+  g_file_info_set_attribute_uint32 (fi, "unix::gid", 0);
+  g_file_info_set_attribute_uint32 (fi, "unix::mode", (0755 | S_IFDIR));
+
+  g_autoptr(GVariant) dirmeta = ostree_create_directory_metadata (fi, NULL /* xattrs */);
+
+  g_autofree guchar *csum_raw = NULL;
+  if (!ostree_repo_write_metadata (self, OSTREE_OBJECT_TYPE_DIR_META, NULL,
+                                   dirmeta, &csum_raw, cancellable, error))
+    return FALSE;
+
+  g_autofree char *csum = ostree_checksum_from_bytes (csum_raw);
+  ostree_mutable_tree_set_metadata_checksum (mtree, csum);
+
+  g_autoptr(OstreeRepoFile) repo_file = NULL;
+  if (!ostree_repo_write_mtree (self, mtree, (GFile **) &repo_file, cancellable, error))
+    return FALSE;
+
+  g_autofree gchar *new_checksum = NULL;
+  if (!ostree_repo_write_commit (self, old_checksum,
+                                 NULL  /* subject */, NULL  /* body */,
+                                 metadata, repo_file,
+                                 &new_checksum,
+                                 cancellable, error))
+    return FALSE;
+
+  ostree_repo_transaction_set_collection_ref (self, &collection_ref, new_checksum);
+
+  if (out_checksum != NULL)
+    *out_checksum = g_steal_pointer (&new_checksum);
+
+  return TRUE;
+}
diff --git a/src/libostree/ostree-repo-private.h b/src/libostree/ostree-repo-private.h
index 9a0ea2be..17993574 100644
--- a/src/libostree/ostree-repo-private.h
+++ b/src/libostree/ostree-repo-private.h
@@ -523,6 +523,13 @@ ostree_repo_list_objects_set (OstreeRepo                  *self,
                               GCancellable                *cancellable,
                               GError                     **error);
 
+gboolean
+_ostree_repo_transaction_write_repo_metadata (OstreeRepo    *self,
+                                              GVariant      *additional_metadata,
+                                              char         **out_checksum,
+                                              GCancellable  *cancellable,
+                                              GError       **error);
+
 /**
  * OstreeRepoAutoTransaction:
  *
diff --git a/src/libostree/ostree-repo.c b/src/libostree/ostree-repo.c
index b4e2be4f..2816002e 100644
--- a/src/libostree/ostree-repo.c
+++ b/src/libostree/ostree-repo.c
@@ -6237,6 +6237,7 @@ summary_add_ref_entry (OstreeRepo       *self,
 
 static gboolean
 regenerate_metadata (OstreeRepo    *self,
+                     gboolean       do_metadata_commit,
                      GVariant      *additional_metadata,
                      GVariant      *options,
                      GCancellable  *cancellable,
@@ -6279,12 +6280,70 @@ regenerate_metadata (OstreeRepo    *self,
         }
     }
 
+  const gchar *main_collection_id = ostree_repo_get_collection_id (self);
+
+  /* Write out a new metadata commit for the repository when it has a collection ID. */
+  if (do_metadata_commit && main_collection_id != NULL)
+    {
+      g_autoptr(OstreeRepoAutoTransaction) txn =
+        _ostree_repo_auto_transaction_start (self, cancellable, error);
+      if (!txn)
+        return FALSE;
+
+      /* Disable automatic summary updating since we're already doing it */
+      self->txn.disable_auto_summary = TRUE;
+
+      g_autofree gchar *new_ostree_metadata_checksum = NULL;
+      if (!_ostree_repo_transaction_write_repo_metadata (self,
+                                                         additional_metadata,
+                                                         &new_ostree_metadata_checksum,
+                                                         cancellable,
+                                                         error))
+        return FALSE;
+
+      /* Sign the new commit. */
+      if (gpg_key_ids != NULL)
+        {
+          for (const char * const *iter = (const char * const *) gpg_key_ids;
+               iter != NULL && *iter != NULL; iter++)
+            {
+              const char *gpg_key_id = *iter;
+
+              if (!ostree_repo_sign_commit (self,
+                                            new_ostree_metadata_checksum,
+                                            gpg_key_id,
+                                            gpg_homedir,
+                                            cancellable,
+                                            error))
+                return FALSE;
+            }
+        }
+
+      if (sign_keys != NULL)
+        {
+          GVariantIter *iter;
+          GVariant *key;
+
+          g_variant_get (sign_keys, "av", &iter);
+          while (g_variant_iter_loop (iter, "v", &key))
+            {
+              if (!ostree_sign_set_sk (sign, key, error))
+                return FALSE;
+
+              if (!ostree_sign_commit (sign, self, new_ostree_metadata_checksum,
+                                       cancellable, error))
+                return FALSE;
+            }
+        }
+
+      if (!_ostree_repo_auto_transaction_commit (txn, NULL, cancellable, error))
+        return FALSE;
+    }
+
   g_auto(GVariantDict) additional_metadata_builder = OT_VARIANT_BUILDER_INITIALIZER;
   g_variant_dict_init (&additional_metadata_builder, additional_metadata);
   g_autoptr(GVariantBuilder) refs_builder = g_variant_builder_new (G_VARIANT_TYPE ("a(s(taya{sv}))"));
 
-  const gchar *main_collection_id = ostree_repo_get_collection_id (self);
-
   {
     if (main_collection_id == NULL)
       {
@@ -6520,7 +6579,7 @@ ostree_repo_regenerate_summary (OstreeRepo     *self,
                                 GCancellable   *cancellable,
                                 GError        **error)
 {
-  return regenerate_metadata (self, additional_metadata, NULL, cancellable, error);
+  return regenerate_metadata (self, FALSE, additional_metadata, NULL, cancellable, error);
 }
 
 /**
@@ -6538,6 +6597,9 @@ ostree_repo_regenerate_summary (OstreeRepo     *self,
  * ostree_repo_regenerate_summary() and %OSTREE_SUMMARY_GVARIANT_FORMAT for
  * additional details on its contents.
  *
+ * Additionally, if the `core/collection-id` key is set in the configuration, a
+ * %OSTREE_REPO_METADATA_REF commit will be created.
+ *
  * The following @options are currently defined:
  *
  *   * `gpg-key-ids` (`as`): Array of GPG key IDs to sign the metadata with.
@@ -6558,7 +6620,7 @@ ostree_repo_regenerate_metadata (OstreeRepo    *self,
                                  GCancellable  *cancellable,
                                  GError       **error)
 {
-  return regenerate_metadata (self, additional_metadata, options, cancellable, error);
+  return regenerate_metadata (self, TRUE, additional_metadata, options, cancellable, error);
 }
 
 /* Regenerate the summary if `core/auto-update-summary` is set. We default to FALSE for