lib/repo-finder: Add config-file based OstreeRepoFinder implementation

This is a basic implementation of OstreeRepoFinder which resolves ref
names to remote URIs by looking their collection IDs up in the local
configuration of remotes who have their collection-id key set.

Unit tests are included.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #924
Approved by: cgwalters

Makefile-libostree-defines.am

@@ -43,6 +43,7 @@ libostree_public_headers += \
 	src/libostree/ostree-ref.h \
 	src/libostree/ostree-remote.h \
 	src/libostree/ostree-repo-finder.h \
+	src/libostree/ostree-repo-finder-config.h \
 	$(NULL)
 endif
 

Makefile-libostree.am

@@ -155,10 +155,12 @@ libostree_1_la_SOURCES += \
 	src/libostree/ostree-ref.h \
 	src/libostree/ostree-remote.h \
 	src/libostree/ostree-repo-finder.h \
+	src/libostree/ostree-repo-finder-config.h \
 	$(NULL)
 else # if ENABLE_EXPERIMENTAL_API
 libostree_1_la_SOURCES += \
 	src/libostree/ostree-repo-finder.c \
+	src/libostree/ostree-repo-finder-config.c \
 	$(NULL)
 endif
 
@@ -235,7 +237,7 @@ OSTree_1_0_gir_INCLUDES = Gio-2.0
 OSTree_1_0_gir_CFLAGS = $(libostree_1_la_CFLAGS)
 OSTree_1_0_gir_LIBS = libostree-1.la
 OSTree_1_0_gir_SCANNERFLAGS = --warn-all --identifier-prefix=Ostree --symbol-prefix=ostree
-OSTree_1_0_gir_FILES = $(libostreeinclude_HEADERS) $(filter-out %-private.h %/ostree-soup-uri.h %/ostree-repo-finder.h,$(libostree_1_la_SOURCES))
+OSTree_1_0_gir_FILES = $(libostreeinclude_HEADERS) $(filter-out %-private.h %/ostree-soup-uri.h %/ostree-repo-finder.h %/ostree-repo-finder-config.h,$(libostree_1_la_SOURCES))
 INTROSPECTION_GIRS += OSTree-1.0.gir
 gir_DATA += OSTree-1.0.gir
 typelib_DATA += OSTree-1.0.typelib

Makefile-tests.am

@@ -193,6 +193,12 @@ _installed_or_uninstalled_test_programs = tests/test-varint tests/test-ot-unix-u
 	tests/test-gpg-verify-result tests/test-checksum tests/test-lzma tests/test-rollsum \
 	tests/test-basic-c tests/test-sysroot-c tests/test-pull-c
 
+if ENABLE_EXPERIMENTAL_API
+test_programs += \
+	tests/test-repo-finder-config \
+	$(NULL)
+endif
+
 # An interactive tool
 noinst_PROGRAMS += tests/test-rollsum-cli
 
@@ -219,6 +225,10 @@ tests_test_rollsum_SOURCES = src/libostree/ostree-rollsum.c tests/test-rollsum.c
 tests_test_rollsum_CFLAGS = $(TESTS_CFLAGS) $(OT_DEP_ZLIB_CFLAGS)
 tests_test_rollsum_LDADD = $(bupsplitpath) $(TESTS_LDADD) $(OT_DEP_ZLIB_LIBS)
 
+tests_test_repo_finder_config_SOURCES = tests/test-repo-finder-config.c
+tests_test_repo_finder_config_CFLAGS = $(TESTS_CFLAGS)
+tests_test_repo_finder_config_LDADD = $(TESTS_LDADD)
+
 tests_test_mutable_tree_CFLAGS = $(TESTS_CFLAGS)
 tests_test_mutable_tree_LDADD = $(TESTS_LDADD)
 

apidoc/ostree-experimental-sections.txt

@@ -49,6 +49,14 @@ ostree_repo_finder_get_type
 ostree_repo_finder_result_get_type
 </SECTION>
 
+<SECTION>
+<FILE>ostree-repo-finder-config</FILE>
+OstreeRepoFinderConfig
+ostree_repo_finder_config_new
+<SUBSECTION Standard>
+ostree_repo_finder_config_get_type
+</SECTION>
+
 <SECTION>
 <FILE>ostree-misc-experimental</FILE>
 ostree_repo_get_collection_id

src/libostree/libostree-experimental.sym

@@ -47,6 +47,8 @@ global:
   ostree_collection_ref_new;
   ostree_repo_find_remotes_async;
   ostree_repo_find_remotes_finish;
+  ostree_repo_finder_config_get_type;
+  ostree_repo_finder_config_new;
   ostree_repo_finder_get_type;
   ostree_repo_finder_resolve_async;
   ostree_repo_finder_resolve_all_async;

src/libostree/ostree-autocleanups.h

@@ -64,6 +64,7 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeCollectionRef, ostree_collection_ref_free)
 G_DEFINE_AUTO_CLEANUP_FREE_FUNC (OstreeCollectionRefv, ostree_collection_ref_freev, NULL)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRemote, ostree_remote_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinder, g_object_unref)
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinderConfig, g_object_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinderResult, ostree_repo_finder_result_free)
 G_DEFINE_AUTO_CLEANUP_FREE_FUNC (OstreeRepoFinderResultv, ostree_repo_finder_result_freev, NULL)
 #endif  /* OSTREE_ENABLE_EXPERIMENTAL_API */

src/libostree/ostree-core-private.h

@@ -187,6 +187,9 @@ G_DEFINE_AUTO_CLEANUP_FREE_FUNC (OstreeCollectionRefv, ostree_collection_ref_fre
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinder, g_object_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinderResult, ostree_repo_finder_result_free)
 G_DEFINE_AUTO_CLEANUP_FREE_FUNC (OstreeRepoFinderResultv, ostree_repo_finder_result_freev, NULL)
+
+#include "ostree-repo-finder-config.h"
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (OstreeRepoFinderConfig, g_object_unref)
 #endif
 
 G_END_DECLS

src/libostree/ostree-repo-finder-config.c

@@ -0,0 +1,235 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2017 Endless Mobile, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include <fcntl.h>
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+#include <libglnx.h>
+
+#include "ostree-remote-private.h"
+#include "ostree-repo.h"
+#include "ostree-repo-private.h"
+#include "ostree-repo-finder.h"
+#include "ostree-repo-finder-config.h"
+
+/**
+ * SECTION:ostree-repo-finder-config
+ * @title: OstreeRepoFinderConfig
+ * @short_description: Finds remote repositories from ref names using the local
+ *    repository configuration files
+ * @stability: Unstable
+ * @include: libostree/ostree-repo-finder-config.h
+ *
+ * #OstreeRepoFinderConfig is an implementation of #OstreeRepoFinder which looks
+ * refs up in locally configured remotes and returns remote URIs.
+ * Duplicate remote URIs are combined into a single #OstreeRepoFinderResult
+ * which lists multiple refs.
+ *
+ * For all the locally configured remotes which have an `collection-id` specified
+ * (see [ostree.repo-config(5)](man:ostree.repo-config(5))), it finds the
+ * intersection of their refs and the set of refs to resolve. If the
+ * intersection is non-empty, that remote is returned as a result. Remotes which
+ * do not have their `collection-id` key configured are ignored.
+ *
+ * Since: 2017.8
+ */
+
+static void ostree_repo_finder_config_iface_init (OstreeRepoFinderInterface *iface);
+
+struct _OstreeRepoFinderConfig
+{
+  GObject parent_instance;
+};
+
+G_DEFINE_TYPE_WITH_CODE (OstreeRepoFinderConfig, ostree_repo_finder_config, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (OSTREE_TYPE_REPO_FINDER, ostree_repo_finder_config_iface_init))
+
+static gint
+results_compare_cb (gconstpointer a,
+                    gconstpointer b)
+{
+  const OstreeRepoFinderResult *result_a = *((const OstreeRepoFinderResult **) a);
+  const OstreeRepoFinderResult *result_b = *((const OstreeRepoFinderResult **) b);
+
+  return ostree_repo_finder_result_compare (result_a, result_b);
+}
+
+static void
+ostree_repo_finder_config_resolve_async (OstreeRepoFinder                  *finder,
+                                         const OstreeCollectionRef * const *refs,
+                                         OstreeRepo                        *parent_repo,
+                                         GCancellable                      *cancellable,
+                                         GAsyncReadyCallback                callback,
+                                         gpointer                           user_data)
+{
+  g_autoptr(GTask) task = NULL;
+  g_autoptr(GPtrArray) results = NULL;
+  const gint priority = 100;  /* arbitrarily chosen; lower than the others */
+  gsize i, j;
+  g_autoptr(GHashTable) repo_name_to_refs = NULL;  /* (element-type utf8 GHashTable) */
+  GHashTable *supported_ref_to_checksum;  /* (element-type OstreeCollectionRef utf8) */
+  GHashTableIter iter;
+  const gchar *remote_name;
+  g_auto(GStrv) remotes = NULL;
+  gsize n_remotes = 0;
+
+  task = g_task_new (finder, cancellable, callback, user_data);
+  g_task_set_source_tag (task, ostree_repo_finder_config_resolve_async);
+  results = g_ptr_array_new_with_free_func ((GDestroyNotify) ostree_repo_finder_result_free);
+  repo_name_to_refs = g_hash_table_new_full (g_str_hash, g_str_equal, NULL,
+                                             (GDestroyNotify) g_hash_table_unref);
+
+  /* List all remotes in this #OstreeRepo and see which of their ref lists
+   * intersect with @refs. */
+  remotes = ostree_repo_remote_list (parent_repo, (guint *) &n_remotes);
+
+  g_debug ("%s: Checking %" G_GSIZE_FORMAT " remotes", G_STRFUNC, n_remotes);
+
+  for (i = 0; i < n_remotes; i++)
+    {
+      g_autoptr(GError) local_error = NULL;
+      g_autoptr(GHashTable) remote_refs = NULL;  /* (element-type utf8 utf8) */
+      const gchar *checksum;
+      g_autofree gchar *remote_collection_id = NULL;
+
+      remote_name = remotes[i];
+
+      if (!ostree_repo_get_remote_option (parent_repo, remote_name, "collection-id",
+                                          NULL, &remote_collection_id, &local_error) ||
+          !ostree_validate_collection_id (remote_collection_id, &local_error))
+        {
+          g_debug ("Ignoring remote ‘%s’ due to no valid collection ID being configured for it: %s",
+                   remote_name, local_error->message);
+          g_clear_error (&local_error);
+          continue;
+        }
+
+      if (!ostree_repo_remote_list_refs (parent_repo, remote_name, &remote_refs,
+                                         cancellable, &local_error))
+        {
+          g_debug ("Ignoring remote ‘%s’ due to error loading its refs: %s",
+                   remote_name, local_error->message);
+          g_clear_error (&local_error);
+          continue;
+        }
+
+      for (j = 0; refs[j] != NULL; j++)
+        {
+          if (g_strcmp0 (refs[j]->collection_id, remote_collection_id) == 0 &&
+              g_hash_table_lookup_extended (remote_refs, refs[j]->ref_name, NULL, (gpointer *) &checksum))
+            {
+              /* The requested ref is listed in the refs for this remote. Add
+               * the remote to the results, and the ref to its
+               * @supported_ref_to_checksum. */
+              g_debug ("Resolved ref (%s, %s) to remote ‘%s’.",
+                       refs[j]->collection_id, refs[j]->ref_name, remote_name);
+
+              supported_ref_to_checksum = g_hash_table_lookup (repo_name_to_refs, remote_name);
+
+              if (supported_ref_to_checksum == NULL)
+                {
+                  supported_ref_to_checksum = g_hash_table_new_full (ostree_collection_ref_hash,
+                                                                     ostree_collection_ref_equal,
+                                                                     NULL, g_free);
+                  g_hash_table_insert (repo_name_to_refs, (gpointer) remote_name, supported_ref_to_checksum  /* transfer */);
+                }
+
+              g_hash_table_insert (supported_ref_to_checksum,
+                                   (gpointer) refs[j], g_strdup (checksum));
+            }
+        }
+    }
+
+  /* Aggregate the results. */
+  g_hash_table_iter_init (&iter, repo_name_to_refs);
+
+  while (g_hash_table_iter_next (&iter, (gpointer *) &remote_name, (gpointer *) &supported_ref_to_checksum))
+    {
+      g_autoptr(GError) local_error = NULL;
+      OstreeRemote *remote;
+
+      /* We don’t know what last-modified timestamp the remote has without
+       * making expensive HTTP queries, so leave that information blank. We
+       * assume that the configuration which says the refs and commits in
+       * @supported_ref_to_checksum are in the repository is correct; the code
+       * in ostree_repo_find_remotes_async() will check that. */
+      remote = _ostree_repo_get_remote_inherited (parent_repo, remote_name, &local_error);
+      if (remote == NULL)
+        {
+          g_debug ("Configuration for remote ‘%s’ could not be found. Ignoring.",
+                   remote_name);
+          continue;
+        }
+
+      g_ptr_array_add (results, ostree_repo_finder_result_new (remote, finder, priority, supported_ref_to_checksum, 0));
+    }
+
+  g_ptr_array_sort (results, results_compare_cb);
+
+  g_task_return_pointer (task, g_steal_pointer (&results), (GDestroyNotify) g_ptr_array_unref);
+}
+
+static GPtrArray *
+ostree_repo_finder_config_resolve_finish (OstreeRepoFinder  *finder,
+                                          GAsyncResult      *result,
+                                          GError           **error)
+{
+  g_return_val_if_fail (g_task_is_valid (result, finder), NULL);
+  return g_task_propagate_pointer (G_TASK (result), error);
+}
+
+static void
+ostree_repo_finder_config_init (OstreeRepoFinderConfig *self)
+{
+  /* Nothing to see here. */
+}
+
+static void
+ostree_repo_finder_config_class_init (OstreeRepoFinderConfigClass *klass)
+{
+  /* Nothing to see here. */
+}
+
+static void
+ostree_repo_finder_config_iface_init (OstreeRepoFinderInterface *iface)
+{
+  iface->resolve_async = ostree_repo_finder_config_resolve_async;
+  iface->resolve_finish = ostree_repo_finder_config_resolve_finish;
+}
+
+/**
+ * ostree_repo_finder_config_new:
+ *
+ * Create a new #OstreeRepoFinderConfig.
+ *
+ * Returns: (transfer full): a new #OstreeRepoFinderConfig
+ * Since: 2017.8
+ */
+OstreeRepoFinderConfig *
+ostree_repo_finder_config_new (void)
+{
+  return g_object_new (OSTREE_TYPE_REPO_FINDER_CONFIG, NULL);
+}

src/libostree/ostree-repo-finder-config.h

@@ -0,0 +1,55 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2017 Endless Mobile, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#pragma once
+
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+
+#include "ostree-repo-finder.h"
+#include "ostree-types.h"
+
+G_BEGIN_DECLS
+
+#define OSTREE_TYPE_REPO_FINDER_CONFIG (ostree_repo_finder_config_get_type ())
+
+/* Manually expanded version of the following, omitting autoptr support (for GLib < 2.44):
+_OSTREE_PUBLIC
+G_DECLARE_FINAL_TYPE (OstreeRepoFinderConfig, ostree_repo_finder_config, OSTREE, REPO_FINDER_CONFIG, GObject) */
+
+_OSTREE_PUBLIC
+GType ostree_repo_finder_config_get_type (void);
+
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+typedef struct _OstreeRepoFinderConfig OstreeRepoFinderConfig;
+typedef struct { GObjectClass parent_class; } OstreeRepoFinderConfigClass;
+
+static inline OstreeRepoFinderConfig *OSTREE_REPO_FINDER_CONFIG (gpointer ptr) { return G_TYPE_CHECK_INSTANCE_CAST (ptr, ostree_repo_finder_config_get_type (), OstreeRepoFinderConfig); }
+static inline gboolean OSTREE_IS_REPO_FINDER_CONFIG (gpointer ptr) { return G_TYPE_CHECK_INSTANCE_TYPE (ptr, ostree_repo_finder_config_get_type ()); }
+G_GNUC_END_IGNORE_DEPRECATIONS
+
+_OSTREE_PUBLIC
+OstreeRepoFinderConfig *ostree_repo_finder_config_new (void);
+
+G_END_DECLS

src/libostree/ostree-repo-pull.c

@@ -41,6 +41,7 @@
 
 #ifdef OSTREE_ENABLE_EXPERIMENTAL_API
 #include "ostree-repo-finder.h"
+#include "ostree-repo-finder-config.h"
 #endif /* OSTREE_ENABLE_EXPERIMENTAL_API */
 
 #include <gio/gunixinputstream.h>
@@ -4085,6 +4086,7 @@ ostree_repo_find_remotes_async (OstreeRepo                     *self,
   g_autoptr(FindRemotesData) data = NULL;
   GMainContext *context;
   OstreeRepoFinder *default_finders[4] = { NULL, };
+  g_autoptr(OstreeRepoFinder) finder_config = NULL;
 
   g_return_if_fail (OSTREE_IS_REPO (self));
   g_return_if_fail (is_valid_collection_ref_array (refs));
@@ -4103,6 +4105,10 @@ ostree_repo_find_remotes_async (OstreeRepo                     *self,
   /* Are we using #OstreeRepoFinders provided by the user, or the defaults? */
   if (finders == NULL)
     {
+      finder_config = OSTREE_REPO_FINDER (ostree_repo_finder_config_new ());
+
+      default_finders[0] = finder_config;
+
       finders = default_finders;
     }
 

src/libostree/ostree.h

@@ -38,6 +38,7 @@
 #ifdef OSTREE_ENABLE_EXPERIMENTAL_API
 #include <ostree-ref.h>
 #include <ostree-repo-finder.h>
+#include <ostree-repo-finder-config.h>
 #endif /* OSTREE_ENABLE_EXPERIMENTAL_API */
 
 #include <ostree-autocleanups.h>

tests/.gitignore

@@ -14,4 +14,5 @@ test-mutable-tree
 test-ot-opt-utils
 test-ot-tool-util
 test-ot-unix-utils
+test-repo-finder-config
 test-rollsum-cli

tests/test-repo-finder-config.c

@@ -0,0 +1,327 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2017 Endless Mobile, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+#include <libglnx.h>
+#include <locale.h>
+#include <string.h>
+
+#include "libostreetest.h"
+#include "ostree-autocleanups.h"
+#include "ostree-repo-finder.h"
+#include "ostree-repo-finder-config.h"
+
+/* Test fixture. Creates a temporary directory. */
+typedef struct
+{
+  OstreeRepo *parent_repo;  /* owned */
+  int working_dfd;  /* owned */
+  GFile *working_dir;  /* owned */
+} Fixture;
+
+static void
+setup (Fixture       *fixture,
+       gconstpointer  test_data)
+{
+  g_autofree gchar *tmp_name = NULL;
+  g_autoptr(GError) error = NULL;
+
+  tmp_name = g_strdup ("test-repo-finder-config-XXXXXX");
+  glnx_mkdtempat_open_in_system (tmp_name, 0700, &fixture->working_dfd, &error);
+  g_assert_no_error (error);
+
+  g_test_message ("Using temporary directory: %s", tmp_name);
+
+  glnx_shutil_mkdir_p_at (fixture->working_dfd, "repo", 0700, NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(GFile) tmp_dir = g_file_new_for_path (g_get_tmp_dir ());
+  fixture->working_dir = g_file_get_child (tmp_dir, tmp_name);
+
+  fixture->parent_repo = ot_test_setup_repo (NULL, &error);
+  g_assert_no_error (error);
+}
+
+static void
+teardown (Fixture       *fixture,
+          gconstpointer  test_data)
+{
+  glnx_fd_close int parent_repo_dfd = -1;
+  g_autoptr(GError) error = NULL;
+
+  /* Recursively remove the temporary directory. */
+  glnx_shutil_rm_rf_at (fixture->working_dfd, ".", NULL, NULL);
+
+  close (fixture->working_dfd);
+  fixture->working_dfd = -1;
+
+  /* The repo also needs its source files to be removed. This is the inverse
+   * of setup_test_repository() in libtest.sh. */
+  g_autofree gchar *parent_repo_path = g_file_get_path (ostree_repo_get_path (fixture->parent_repo));
+  glnx_opendirat (-1, parent_repo_path, TRUE, &parent_repo_dfd, &error);
+  g_assert_no_error (error);
+
+  glnx_shutil_rm_rf_at (parent_repo_dfd, "../files", NULL, NULL);
+  glnx_shutil_rm_rf_at (parent_repo_dfd, "../repo", NULL, NULL);
+
+  g_clear_object (&fixture->working_dir);
+  g_clear_object (&fixture->parent_repo);
+}
+
+/* Test the object constructor works at a basic level. */
+static void
+test_repo_finder_config_init (void)
+{
+  g_autoptr(OstreeRepoFinderConfig) finder = NULL;
+
+  /* Default everything. */
+  finder = ostree_repo_finder_config_new ();
+}
+
+static void
+result_cb (GObject      *source_object,
+           GAsyncResult *result,
+           gpointer      user_data)
+{
+  GAsyncResult **result_out = user_data;
+  *result_out = g_object_ref (result);
+}
+
+/* Test that no remotes are found if there are no config files in the refs
+ * directory. */
+static void
+test_repo_finder_config_no_configs (Fixture       *fixture,
+                                    gconstpointer  test_data)
+{
+  g_autoptr(OstreeRepoFinderConfig) finder = NULL;
+  g_autoptr(GMainContext) context = NULL;
+  g_autoptr(GAsyncResult) result = NULL;
+  g_autoptr(GPtrArray) results = NULL;  /* (element-type OstreeRepoFinderResult) */
+  g_autoptr(GError) error = NULL;
+  const OstreeCollectionRef ref1 = { "org.example.Os", "exampleos/x86_64/standard" };
+  const OstreeCollectionRef ref2 = { "org.example.Os", "exampleos/x86_64/buildmaster/standard" };
+  const OstreeCollectionRef * const refs[] = { &ref1, &ref2, NULL };
+
+  context = g_main_context_new ();
+  g_main_context_push_thread_default (context);
+
+  finder = ostree_repo_finder_config_new ();
+
+  ostree_repo_finder_resolve_async (OSTREE_REPO_FINDER (finder), refs,
+                                    fixture->parent_repo, NULL, result_cb, &result);
+
+  while (result == NULL)
+    g_main_context_iteration (context, TRUE);
+
+  results = ostree_repo_finder_resolve_finish (OSTREE_REPO_FINDER (finder),
+                                               result, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (results);
+  g_assert_cmpuint (results->len, ==, 0);
+
+  g_main_context_pop_thread_default (context);
+}
+
+/* Add configuration for a remote named @remote_name, at @remote_uri, with a
+ * remote collection ID of @collection_id, to the given @repo. */
+static void
+assert_create_remote_config (OstreeRepo  *repo,
+                             const gchar *remote_name,
+                             const gchar *remote_uri,
+                             const gchar *collection_id)
+{
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GVariant) options = NULL;
+
+  if (collection_id != NULL)
+    options = g_variant_new_parsed ("@a{sv} { 'collection-id': <%s> }",
+                                    collection_id);
+
+  ostree_repo_remote_add (repo, remote_name, remote_uri, options, NULL, &error);
+  g_assert_no_error (error);
+}
+
+static gchar *assert_create_remote (Fixture     *fixture,
+                                    const gchar *collection_id,
+                                    ...) G_GNUC_NULL_TERMINATED;
+
+/* Create a new repository in a temporary directory with its collection ID set
+ * to @collection_id, and containing the refs given in @... (which must be
+ * %NULL-terminated). Return the `file://` URI of the new repository. */
+static gchar *
+assert_create_remote (Fixture     *fixture,
+                      const gchar *collection_id,
+                      ...)
+{
+  va_list args;
+  g_autoptr(GError) error = NULL;
+  const gchar *repo_name = (collection_id != NULL) ? collection_id : "no-collection";
+
+  glnx_shutil_mkdir_p_at (fixture->working_dfd, repo_name, 0700, NULL, &error);
+  g_assert_no_error (error);
+
+  g_autoptr(GFile) repo_path = g_file_get_child (fixture->working_dir, repo_name);
+  g_autoptr(OstreeRepo) repo = ostree_repo_new (repo_path);
+  ostree_repo_set_collection_id (repo, collection_id, &error);
+  g_assert_no_error (error);
+  ostree_repo_create (repo, OSTREE_REPO_MODE_ARCHIVE_Z2, NULL, &error);
+  g_assert_no_error (error);
+
+  /* Set up the refs from @.... */
+  va_start (args, collection_id);
+
+  for (const gchar *ref_name = va_arg (args, const gchar *);
+       ref_name != NULL;
+       ref_name = va_arg (args, const gchar *))
+    {
+      OstreeCollectionRef collection_ref = { (gchar *) collection_id, (gchar *) ref_name };
+      g_autofree gchar *checksum = NULL;
+      g_autoptr(OstreeMutableTree) mtree = NULL;
+      g_autoptr(OstreeRepoFile) repo_file = NULL;
+
+      mtree = ostree_mutable_tree_new ();
+      ostree_repo_write_dfd_to_mtree (repo, AT_FDCWD, ".", mtree, NULL, NULL, &error);
+      g_assert_no_error (error);
+      ostree_repo_write_mtree (repo, mtree, (GFile **) &repo_file, NULL, &error);
+      g_assert_no_error (error);
+
+      ostree_repo_write_commit (repo, NULL  /* no parent */, ref_name, ref_name,
+                                NULL  /* no metadata */, repo_file, &checksum,
+                                NULL, &error);
+      g_assert_no_error (error);
+
+      if (collection_id != NULL)
+        ostree_repo_set_collection_ref_immediate (repo, &collection_ref, checksum, NULL, &error);
+      else
+        ostree_repo_set_ref_immediate (repo, NULL, ref_name, checksum, NULL, &error);
+      g_assert_no_error (error);
+    }
+
+  va_end (args);
+
+  /* Update the summary. */
+  ostree_repo_regenerate_summary (repo, NULL  /* no metadata */, NULL, &error);
+  g_assert_no_error (error);
+
+  return g_file_get_uri (repo_path);
+}
+
+/* Test resolving the refs against a collection of config files, which contain
+ * valid, invalid or duplicate repo information. */
+static void
+test_repo_finder_config_mixed_configs (Fixture       *fixture,
+                                       gconstpointer  test_data)
+{
+  g_autoptr(OstreeRepoFinderConfig) finder = NULL;
+  g_autoptr(GMainContext) context = NULL;
+  g_autoptr(GAsyncResult) result = NULL;
+  g_autoptr(GPtrArray) results = NULL;  /* (element-type OstreeRepoFinderResult) */
+  g_autoptr(GError) error = NULL;
+  gsize i;
+  const OstreeCollectionRef ref0 = { "org.example.Collection0", "exampleos/x86_64/ref0" };
+  const OstreeCollectionRef ref1 = { "org.example.Collection0", "exampleos/x86_64/ref1" };
+  const OstreeCollectionRef ref2 = { "org.example.Collection1", "exampleos/x86_64/ref1" };
+  const OstreeCollectionRef ref3 = { "org.example.Collection1", "exampleos/x86_64/ref2" };
+  const OstreeCollectionRef ref4 = { "org.example.Collection2", "exampleos/x86_64/ref3" };
+  const OstreeCollectionRef * const refs[] = { &ref0, &ref1, &ref2, &ref3, &ref4, NULL };
+
+  context = g_main_context_new ();
+  g_main_context_push_thread_default (context);
+
+  /* Put together various ref configuration files. */
+  g_autofree gchar *collection0_uri = assert_create_remote (fixture, "org.example.Collection0",
+                                                            "exampleos/x86_64/ref0",
+                                                            "exampleos/x86_64/ref1",
+                                                            NULL);
+  g_autofree gchar *collection1_uri = assert_create_remote (fixture, "org.example.Collection1",
+                                                            "exampleos/x86_64/ref2",
+                                                            NULL);
+  g_autofree gchar *no_collection_uri = assert_create_remote (fixture, NULL,
+                                                              "exampleos/x86_64/ref3",
+                                                              NULL);
+
+  assert_create_remote_config (fixture->parent_repo, "remote0", collection0_uri, "org.example.Collection0");
+  assert_create_remote_config (fixture->parent_repo, "remote1", collection1_uri, "org.example.Collection1");
+  assert_create_remote_config (fixture->parent_repo, "remote0-copy", collection0_uri, "org.example.Collection0");
+  assert_create_remote_config (fixture->parent_repo, "remote1-bad-copy", collection1_uri, "org.example.NotCollection1");
+  assert_create_remote_config (fixture->parent_repo, "remote2", no_collection_uri, NULL);
+
+  finder = ostree_repo_finder_config_new ();
+
+  /* Resolve the refs. */
+  ostree_repo_finder_resolve_async (OSTREE_REPO_FINDER (finder), refs,
+                                    fixture->parent_repo, NULL, result_cb, &result);
+
+  while (result == NULL)
+    g_main_context_iteration (context, TRUE);
+
+  results = ostree_repo_finder_resolve_finish (OSTREE_REPO_FINDER (finder),
+                                               result, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (results);
+  g_assert_cmpuint (results->len, ==, 3);
+
+  /* Check that the results are correct: the invalid refs should have been
+   * ignored, and the valid results canonicalised and deduplicated. */
+  for (i = 0; i < results->len; i++)
+    {
+      const OstreeRepoFinderResult *result = g_ptr_array_index (results, i);
+
+      if (g_strcmp0 (ostree_remote_get_name (result->remote), "remote0") == 0 ||
+          g_strcmp0 (ostree_remote_get_name (result->remote), "remote0-copy") == 0)
+        {
+          g_assert_cmpuint (g_hash_table_size (result->ref_to_checksum), ==, 2);
+          g_assert_true (g_hash_table_contains (result->ref_to_checksum, &ref0));
+          g_assert_true (g_hash_table_contains (result->ref_to_checksum, &ref1));
+        }
+      else if (g_strcmp0 (ostree_remote_get_name (result->remote), "remote1") == 0)
+        {
+          g_assert_cmpuint (g_hash_table_size (result->ref_to_checksum), ==, 1);
+          g_assert_true (g_hash_table_contains (result->ref_to_checksum, &ref3));
+        }
+      else
+        {
+          g_assert_not_reached ();
+        }
+    }
+
+  g_main_context_pop_thread_default (context);
+}
+
+int main (int argc, char **argv)
+{
+  setlocale (LC_ALL, "");
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/repo-finder-config/init", test_repo_finder_config_init);
+  g_test_add ("/repo-finder-config/no-configs", Fixture, NULL, setup,
+              test_repo_finder_config_no_configs, teardown);
+  g_test_add ("/repo-finder-config/mixed-configs", Fixture, NULL, setup,
+              test_repo_finder_config_mixed_configs, teardown);
+
+  return g_test_run();
+}