Adapt crun to work with Podman's checkpoint/restore expectations

src/libcrun/container.c

@@ -2522,8 +2522,15 @@ libcrun_container_checkpoint (libcrun_context_t *context, const char *id,
   ret = read_container_config_from_state (&container, state_root, id, err);
   if (UNLIKELY (ret < 0))
     return ret;
-  return libcrun_container_checkpoint_linux (&status, container, cr_options,
-                                             err);
+  ret = libcrun_container_checkpoint_linux (&status, container, cr_options,
+                                            err);
+  if (UNLIKELY (ret < 0))
+    return ret;
+
+  if (!cr_options->leave_running)
+    return container_delete_internal (context, NULL, id, true, true, err);
+
+  return 0;
 }
 
 int
@@ -2532,8 +2539,7 @@ libcrun_container_restore (libcrun_context_t *context, const char *id,
                            libcrun_error_t *err)
 {
   cleanup_free libcrun_container_t *container = NULL;
-  runtime_spec_schema_config_schema *def = NULL;
-  const char *state_root = context->state_root;
+  runtime_spec_schema_config_schema *def;
   cleanup_free char *cgroup_path = NULL;
   libcrun_container_status_t status;
   int cgroup_mode, cgroup_manager;
@@ -2542,23 +2548,33 @@ libcrun_container_restore (libcrun_context_t *context, const char *id,
   gid_t root_gid = -1;
   int ret;
 
-  memset (&status, 0, sizeof (status));
-  ret = libcrun_read_container_status (&status, state_root, id, err);
+  container = libcrun_container_load_from_file ("config.json", err);
+  if (container == NULL)
+    return -1;
+
+  container->context = context;
+  def = container->container_def;
+
+  if (def->oci_version && strstr (def->oci_version, "1.0") == NULL)
+    return crun_make_error (err, 0, "unknown version specified");
+
+  ret = check_config_file (def, err);
   if (UNLIKELY (ret < 0))
     return ret;
 
-  ret = libcrun_is_container_running (&status, err);
+  ret = libcrun_status_check_directories (context->state_root, context->id, err);
   if (UNLIKELY (ret < 0))
     return ret;
-  if (ret == 1)
-    return crun_make_error (err, 0,
-                            "the container `%s` is not in 'stopped' state",
-                            id);
 
-  ret = read_container_config_from_state (&container, state_root, id, err);
+  ret = libcrun_copy_config_file (context->id, context->state_root, context->bundle, err);
   if (UNLIKELY (ret < 0))
     return ret;
 
+  /* The CRIU restore code uses bundle and rootfs of status. */
+  memset (&status, 0, sizeof (status));
+  status.bundle = xstrdup(context->bundle);
+  status.rootfs = xstrdup (def->root->path);
+
   ret = libcrun_container_restore_linux (&status, container, cr_options, err);
   if (UNLIKELY (ret < 0))
     return ret;
@@ -2620,6 +2636,15 @@ libcrun_container_restore (libcrun_context_t *context, const char *id,
   if (UNLIKELY (ret < 0))
     return ret;
 
+  if (context->pid_file)
+    {
+      char buf[12];
+      size_t buf_len = sprintf (buf, "%d", status.pid);
+      ret = write_file (context->pid_file, buf, buf_len, err);
+      if (UNLIKELY (ret < 0))
+        return ret;
+    }
+
   if (!cr_options->detach)
     {
       int wait_status;

src/libcrun/criu.c

@@ -170,9 +170,9 @@ libcrun_container_restore_linux_criu (libcrun_container_status_t *status,
 
   runtime_spec_schema_config_schema *def = container->container_def;
   cleanup_close int image_fd = -1;
-  cleanup_free char *path = NULL;
   cleanup_free char *root = NULL;
   cleanup_close int work_fd = -1;
+  int ret_out;
   size_t i;
   int ret;
 
@@ -237,8 +237,6 @@ libcrun_container_restore_linux_criu (libcrun_container_status_t *status,
         criu_add_ext_mount (def->linux->masked_paths[i], "/dev/null");
     }
 
-  xasprintf (&path, "%s/%s", status->bundle, status->rootfs);
-
   /* Mount the container rootfs for CRIU. */
   xasprintf (&root, "%s/criu-root", status->bundle);
 
@@ -247,7 +245,7 @@ libcrun_container_restore_linux_criu (libcrun_container_status_t *status,
     return crun_make_error (err, errno,
                             "error creating restore directory %s\n", root);
   /* do realpath on root */
-  ret = mount (path, root, NULL, MS_BIND | MS_REC, NULL);
+  ret = mount (status->rootfs, root, NULL, MS_BIND | MS_REC, NULL);
   if (UNLIKELY (ret == -1))
     {
       ret = crun_make_error (err, errno,
@@ -258,7 +256,7 @@ libcrun_container_restore_linux_criu (libcrun_container_status_t *status,
   ret = criu_set_root (root);
   if (UNLIKELY (ret != 0))
     {
-      ret = crun_make_error (err, 0, "error setting CRIU root to %s\n", path);
+      ret = crun_make_error (err, 0, "error setting CRIU root to %s\n", root);
       goto out_umount;
     }
 
@@ -294,8 +292,10 @@ libcrun_container_restore_linux_criu (libcrun_container_status_t *status,
     return crun_make_error (err, errno,
                             "error unmounting restore directory %s\n", root);
 out:
-  ret = rmdir (root);
+  ret_out = rmdir (root);
   if (UNLIKELY (ret == -1))
+    return ret;
+  if (UNLIKELY (ret_out == -1))
     return crun_make_error (err, errno,
                             "error removing restore directory %s\n", root);
   return ret;

src/restore.c

@@ -38,14 +38,20 @@ enum
   OPTION_WORK_PATH,
   OPTION_TCP_ESTABLISHED,
   OPTION_SHELL_JOB,
-  OPTION_EXT_UNIX_SK
+  OPTION_EXT_UNIX_SK,
+  OPTION_PID_FILE
 };
 
 static char doc[] = "OCI runtime";
 
+static const char *bundle = NULL;
+
+static libcrun_context_t crun_context;
+
 static libcrun_checkpoint_restore_t cr_options;
 
 static struct argp_option options[] = {
+  {"bundle", 'b', "DIR", 0, "container bundle (default \".\")", 0},
   {"image-path", OPTION_IMAGE_PATH, "DIR", 0,
    "path for saving criu image files", 0},
   {"work-path", OPTION_WORK_PATH, "DIR", 0,
@@ -55,6 +61,8 @@ static struct argp_option options[] = {
   {"ext-unix-sk", OPTION_EXT_UNIX_SK, 0, 0, "allow external unix sockets", 0},
   {"shell-job", OPTION_SHELL_JOB, 0, 0, "allow shell jobs", 0},
   {"detach", 'd', 0, 0, "detach from the container's process", 0},
+  {"pid-file", OPTION_PID_FILE, "FILE", 0,
+   "where to write the PID of the container", 0},
   {0,}
 };
 
@@ -76,6 +84,10 @@ parse_opt (int key, char *arg arg_unused, struct argp_state *state arg_unused)
       cr_options.work_path = argp_mandatory_argument (arg, state);
       break;
 
+    case 'b':
+      bundle = argp_mandatory_argument (arg, state);
+      break;
+
     case OPTION_TCP_ESTABLISHED:
       cr_options.tcp_established = true;
       break;
@@ -92,6 +104,10 @@ parse_opt (int key, char *arg arg_unused, struct argp_state *state arg_unused)
       cr_options.detach = true;
       break;
 
+    case OPTION_PID_FILE:
+      crun_context.pid_file = argp_mandatory_argument (arg, state);
+      break;
+
     default:
       return ARGP_ERR_UNKNOWN;
     }
@@ -106,15 +122,29 @@ int
 crun_command_restore (struct crun_global_arguments *global_args, int argc,
                       char **argv, libcrun_error_t *err)
 {
+  cleanup_free char *bundle_cleanup = NULL;
   cleanup_free char *cr_path = NULL;
   int first_arg;
   int ret;
 
-  libcrun_context_t crun_context = { 0, };
-
   argp_parse (&run_argp, argc, argv, ARGP_IN_ORDER, &first_arg, &cr_options);
   crun_assert_n_args (argc - first_arg, 1, 2);
 
+  /* Make sure the bundle is an absolute path.  */
+  if (bundle)
+    {
+      if (bundle[0] != '/')
+        {
+          bundle_cleanup = realpath (bundle, NULL);
+          if (bundle_cleanup == NULL)
+            libcrun_fail_with_error (errno, "realpath `%s` failed", bundle);
+          bundle = bundle_cleanup;
+        }
+
+      if (chdir (bundle) < 0)
+        libcrun_fail_with_error (errno, "chdir `%s` failed", bundle);
+    }
+
   ret =
     init_libcrun_context (&crun_context, argv[first_arg], global_args, err);
   if (UNLIKELY (ret < 0))
@@ -133,6 +163,7 @@ crun_command_restore (struct crun_global_arguments *global_args, int argc,
       cr_options.image_path = cr_path;
     }
 
+  crun_context.bundle = bundle ? bundle : ".";
   return libcrun_container_restore (&crun_context, argv[first_arg],
                                     &cr_options, err);
 }

tests/test_checkpoint_restore.py

@@ -59,11 +59,19 @@ def test_cr1():
         cmdline_fd.close()
 
         run_crun_command(["_checkpoint", "--image-path=%s" % cr_dir, cid])
-        s = json.loads(run_crun_command(["state", cid]))
-        if s['status'] != "stopped":
-            return -1
 
-        run_crun_command(["_restore", "-d", "--image-path=%s" % cr_dir, cid])
+        bundle = os.path.join(
+            get_tests_root(),
+            cid.split('-')[1]
+        )
+
+        run_crun_command([
+            "_restore",
+            "-d",
+            "--image-path=%s" % cr_dir,
+            "--bundle=%s" % bundle,
+            cid
+        ])
 
         s = json.loads(run_crun_command(["state", cid]))
         if s['status'] != "running":