machined: port machined's bus APIs to use new image metadata API

Let's rework the D-Bus APIs GetImageOSRelease() to use the new internal
metadata API, to query what it needs to know. Augment it with
GetImageHostname(), GetImageMachineID(), GetImageMachineInfo(), that
expose the other new APIS.

1 files changed, 51 insertions, 122 deletions

diff --git a/src/machine/image-dbus.c b/src/machine/image-dbus.c
index c868d623ba..3d2fdd496c 100644
--- a/src/machine/image-dbus.c
+++ b/src/machine/image-dbus.c
@@ -290,159 +290,85 @@ int bus_image_method_set_limit(
         return sd_bus_reply_method_return(message, NULL);
 }
 
-#define EXIT_NOT_FOUND 2
-
-static int directory_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
+int bus_image_method_get_hostname(
+                sd_bus_message *message,
+                void *userdata,
+                sd_bus_error *error) {
 
-        _cleanup_free_ char *path = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        Image *image = userdata;
         int r;
 
-        assert(image);
-        assert(ret);
-
-        r = chase_symlinks("/etc/os-release", image->path, CHASE_PREFIX_ROOT, &path);
-        if (r == -ENOENT)
-                r = chase_symlinks("/usr/lib/os-release", image->path, CHASE_PREFIX_ROOT, &path);
-        if (r == -ENOENT)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to resolve %s: %m", image->path);
-
-        r = load_env_file_pairs(NULL, path, NULL, ret);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to open %s: %m", path);
+        if (!image->metadata_valid) {
+                r = image_read_metadata(image);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to read image metadata: %m");
+        }
 
-        return 0;
+        return sd_bus_reply_method_return(message, "s", image->hostname);
 }
 
-static int raw_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
-        _cleanup_(rmdir_and_freep) char *t = NULL;
-        _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
-        _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
-        _cleanup_(sigkill_waitp) pid_t child = 0;
-        _cleanup_close_pair_ int pair[2] = { -1, -1 };
-        _cleanup_fclose_ FILE *f = NULL;
-        _cleanup_strv_free_ char **v = NULL;
-        siginfo_t si;
-        int r;
-
-        assert(image);
-        assert(ret);
-
-        r = mkdtemp_malloc("/tmp/machined-root-XXXXXX", &t);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to create temporary directory: %m");
-
-        r = loop_device_make_by_path(image->path, O_RDONLY, &d);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to set up loop block device for %s: %m", image->path);
-
-        r = dissect_image(d->fd, NULL, 0, DISSECT_IMAGE_REQUIRE_ROOT, &m);
-        if (r == -ENOPKG)
-                return sd_bus_error_set_errnof(error, r, "Disk image %s not understood: %m", image->path);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to dissect image %s: %m", image->path);
-
-        if (pipe2(pair, O_CLOEXEC) < 0)
-                return sd_bus_error_set_errnof(error, errno, "Failed to create communication pipe: %m");
-
-        child = raw_clone(SIGCHLD|CLONE_NEWNS);
-        if (child < 0)
-                return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
-
-        if (child == 0) {
-                int fd;
-
-                pair[0] = safe_close(pair[0]);
-
-                /* Make sure we never propagate to the host */
-                if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0)
-                        _exit(EXIT_FAILURE);
-
-                r = dissected_image_mount(m, t, DISSECT_IMAGE_READ_ONLY);
-                if (r < 0)
-                        _exit(EXIT_FAILURE);
-
-                r = mount_move_root(t);
-                if (r < 0)
-                        _exit(EXIT_FAILURE);
+int bus_image_method_get_machine_id(
+                sd_bus_message *message,
+                void *userdata,
+                sd_bus_error *error) {
 
-                fd = open("/etc/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
-                if (fd < 0 && errno == ENOENT) {
-                        fd = open("/usr/lib/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
-                        if (fd < 0 && errno == ENOENT)
-                                _exit(EXIT_NOT_FOUND);
-                }
-                if (fd < 0)
-                        _exit(EXIT_FAILURE);
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        Image *image = userdata;
+        int r;
 
-                r = copy_bytes(fd, pair[1], (uint64_t) -1, 0);
+        if (!image->metadata_valid) {
+                r = image_read_metadata(image);
                 if (r < 0)
-                        _exit(EXIT_FAILURE);
-
-                _exit(EXIT_SUCCESS);
+                        return sd_bus_error_set_errnof(error, r, "Failed to read image metadata: %m");
         }
 
-        pair[1] = safe_close(pair[1]);
-
-        f = fdopen(pair[0], "re");
-        if (!f)
-                return -errno;
-
-        pair[0] = -1;
-
-        r = load_env_file_pairs(f, "os-release", NULL, &v);
+        r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
 
-        r = wait_for_terminate(child, &si);
+        if (sd_id128_is_null(image->machine_id)) /* Add an empty array if the ID is zero */
+                r = sd_bus_message_append(reply, "ay", 0);
+        else
+                r = sd_bus_message_append_array(reply, 'y', image->machine_id.bytes, 16);
         if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
-        child = 0;
-        if (si.si_code == CLD_EXITED && si.si_status == EXIT_NOT_FOUND)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
-        if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
-
-        *ret = v;
-        v = NULL;
+                return r;
 
-        return 0;
+        return sd_bus_send(NULL, reply, NULL);
 }
 
-int bus_image_method_get_os_release(
+int bus_image_method_get_machine_info(
                 sd_bus_message *message,
                 void *userdata,
                 sd_bus_error *error) {
 
-        _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
-        _cleanup_strv_free_ char **v = NULL;
         Image *image = userdata;
         int r;
 
-        r = image_path_lock(image->path, LOCK_SH|LOCK_NB, &tree_global_lock, &tree_local_lock);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to lock image: %m");
+        if (!image->metadata_valid) {
+                r = image_read_metadata(image);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to read image metadata: %m");
+        }
 
-        switch (image->type) {
+        return bus_reply_pair_array(message, image->machine_info);
+}
 
-        case IMAGE_DIRECTORY:
-        case IMAGE_SUBVOLUME:
-                r = directory_image_get_os_release(image, &v, error);
-                break;
+int bus_image_method_get_os_release(
+                sd_bus_message *message,
+                void *userdata,
+                sd_bus_error *error) {
 
-        case IMAGE_RAW:
-        case IMAGE_BLOCK:
-                r = raw_image_get_os_release(image, &v, error);
-                break;
+        Image *image = userdata;
+        int r;
 
-        default:
-                assert_not_reached("Unknown image type");
+        if (!image->metadata_valid) {
+                r = image_read_metadata(image);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to read image metadata: %m");
         }
-        if (r < 0)
-                return r;
 
-        return bus_reply_pair_array(message, v);
+        return bus_reply_pair_array(message, image->os_release);
 }
 
 const sd_bus_vtable image_vtable[] = {
@@ -462,6 +388,9 @@ const sd_bus_vtable image_vtable[] = {
         SD_BUS_METHOD("Clone", "sb", NULL, bus_image_method_clone, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("MarkReadOnly", "b", NULL, bus_image_method_mark_read_only, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("SetLimit", "t", NULL, bus_image_method_set_limit, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("GetHostname", NULL, "s", bus_image_method_get_hostname, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("GetMachineID", NULL, "ay", bus_image_method_get_machine_id, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("GetMachineInfo", NULL, "a{ss}", bus_image_method_get_machine_info, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("GetOSRelease", NULL, "a{ss}", bus_image_method_get_os_release, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_VTABLE_END
 };