instance: Create and destroy per-app-ID subdirs of XRD/.flatpak

If we want to provide a per-app-ID XDG_RUNTIME_DIR (#4120) or a
per-app-ID /tmp or /dev/shm (#4093) then we'll need somewhere to put
them. Unlike $XDG_RUNTIME_DIR/app/$FLATPAK_ID, this should be somewhere
that is *not* accessible to the app, so that we can trust its contents.

Signed-off-by: Simon McVittie <smcv@collabora.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/tests/test-instance.c b/tests/test-instance.c
index c73369d7..2ea23e3e 100644
--- a/tests/test-instance.c
+++ b/tests/test-instance.c
@@ -37,19 +37,42 @@
 #include "testlib.h"
 
 static void
+populate_with_files (const char *dir)
+{
+  static const char * const names[] = { "one", "two", "three" };
+  gsize i;
+
+  for (i = 0; i < G_N_ELEMENTS (names); i++)
+    {
+      g_autoptr(GError) error = NULL;
+      g_autofree char *path = g_build_filename (dir, names[i], NULL);
+
+      g_file_set_contents (path, "hello", -1, &error);
+      g_assert_no_error (error);
+    }
+}
+
+static void
 test_gc (void)
 {
   g_autoptr(GBytes) bytes = NULL;
   g_autoptr(GError) error = NULL;
   g_autoptr(GPtrArray) instances = NULL;
   g_autofree char *instances_dir = flatpak_instance_get_instances_directory ();
+  g_autofree char *apps_dir = flatpak_instance_get_instances_directory ();
   g_autofree char *hold_lock = g_test_build_filename (G_TEST_BUILT, "hold-lock", NULL);
+  g_autofree char *alive_app_dir = NULL;
+  g_autofree char *alive_app_lock = NULL;
+  g_autofree char *alive_app_test_cleanup = NULL;
   g_autofree char *alive_instance_dir = NULL;
   g_autofree char *alive_instance_info = NULL;
   g_autofree char *alive_instance_lock = NULL;
   g_autofree char *alive_dead_instance_dir = NULL;
   g_autofree char *alive_dead_instance_info = NULL;
   g_autofree char *alive_dead_instance_lock = NULL;
+  g_autofree char *dead_app_dir = NULL;
+  g_autofree char *dead_app_lock = NULL;
+  g_autofree char *dead_app_test_cleanup = NULL;
   g_autofree char *dead_instance_dir = NULL;
   g_autofree char *dead_instance_info = NULL;
   g_autofree char *dead_instance_lock = NULL;
@@ -59,6 +82,8 @@ test_gc (void)
     "<BUILT>/hold-lock",
     "--lock-file",
     "<instance>/.ref",
+    "--lock-file",
+    "<appID>/.ref",
     NULL
   };
   GPid pid = -1;
@@ -69,6 +94,14 @@ test_gc (void)
 
   /* com.example.Alive has one instance, #1, running.
    * A second instance, #2, was running until recently but has exited. */
+  alive_app_dir = g_build_filename (apps_dir, "com.example.Alive", NULL);
+  g_assert_no_errno (g_mkdir_with_parents (alive_app_dir, 0700));
+  alive_app_test_cleanup = g_build_filename (alive_app_dir, "test-cleanup", NULL);
+  g_assert_no_errno (g_mkdir_with_parents (alive_app_test_cleanup, 0700));
+  populate_with_files (alive_app_test_cleanup);
+  alive_app_lock = g_build_filename (alive_app_dir, ".ref", NULL);
+  g_file_set_contents (alive_app_lock, "", 0, &error);
+  g_assert_no_error (error);
 
   alive_instance_dir = g_build_filename (instances_dir, "1", NULL);
   g_assert_no_errno (g_mkdir_with_parents (alive_instance_dir, 0700));
@@ -100,6 +133,7 @@ test_gc (void)
    * by our own process. */
   hold_lock_argv[0] = hold_lock;
   hold_lock_argv[2] = alive_instance_lock;
+  hold_lock_argv[4] = alive_app_lock;
   g_spawn_async_with_pipes (NULL,
                             (gchar **) hold_lock_argv,
                             NULL,
@@ -117,6 +151,14 @@ test_gc (void)
 
   /* com.example.Dead has no instances running.
    * Instance #4 was running until recently but has exited. */
+  dead_app_dir = g_build_filename (apps_dir, "com.example.Dead", NULL);
+  g_assert_no_errno (g_mkdir_with_parents (dead_app_dir, 0700));
+  dead_app_test_cleanup = g_build_filename (dead_app_dir, "test-cleanup", NULL);
+  g_assert_no_errno (g_mkdir_with_parents (dead_app_test_cleanup, 0700));
+  populate_with_files (dead_app_test_cleanup);
+  dead_app_lock = g_build_filename (dead_app_dir, ".ref", NULL);
+  g_file_set_contents (dead_app_lock, "", 0, &error);
+  g_assert_no_error (error);
 
   dead_instance_dir = g_build_filename (instances_dir, "4", NULL);
   g_assert_no_errno (g_mkdir_with_parents (dead_instance_dir, 0700));
@@ -136,8 +178,10 @@ test_gc (void)
 
   /* Pretend the locks were created in early 1970, to bypass the workaround
    * for a race */
+  g_assert_no_errno (g_utime (alive_app_lock, &a_while_ago));
   g_assert_no_errno (g_utime (alive_instance_lock, &a_while_ago));
   g_assert_no_errno (g_utime (alive_dead_instance_lock, &a_while_ago));
+  g_assert_no_errno (g_utime (dead_app_lock, &a_while_ago));
   g_assert_no_errno (g_utime (dead_instance_lock, &a_while_ago));
 
   /* This has the side-effect of GC'ing instances */
@@ -148,6 +192,19 @@ test_gc (void)
   g_assert_cmpint (stat (alive_dead_instance_dir, &stat_buf) == 0 ? 0 : errno, ==, ENOENT);
   g_assert_cmpint (stat (dead_instance_dir, &stat_buf) == 0 ? 0 : errno, ==, ENOENT);
 
+  /* We don't GC the per-app directories themselves, or their lock files */
+  g_assert_no_errno (stat (alive_app_dir, &stat_buf));
+  g_assert_no_errno (stat (alive_app_lock, &stat_buf));
+  g_assert_no_errno (stat (dead_app_dir, &stat_buf));
+  g_assert_no_errno (stat (dead_app_lock, &stat_buf));
+
+  /* Until we implement something that actively uses this directory,
+   * use the test-cleanup subdirectory to check whether GC took place.
+   * We GC the test-cleanup subdirectory if there is no instance alive.
+   * We do not GC it if there is still an instance holding the lock. */
+  g_assert_no_errno (stat (alive_app_test_cleanup, &stat_buf));
+  g_assert_cmpint (stat (dead_app_test_cleanup, &stat_buf) == 0 ? 0 : errno, ==, ENOENT);
+
   g_assert_cmpuint (instances->len, ==, 1);
   instance = g_ptr_array_index (instances, 0);
   g_assert_true (FLATPAK_IS_INSTANCE (instance));