Remove snapshot unit type

Snapshots were never useful or used for anything. Many systemd
developers that I spoke to at systemd.conf2015, didn't even know they
existed, so it is fairly safe to assume that this type can be deleted
without harm.

The fundamental problem with snapshots is that the state of the system
is dynamic, devices come and go, users log in and out, timers fire...
and restoring all units to some state from the past would "undo"
those changes, which isn't really possible.

Tested by creating a snapshot, running the new binary, and checking
that the transition did not cause errors, and the snapshot is gone,
and snapshots cannot be created anymore.

New systemctl says:
Unknown operation snapshot.
Old systemctl says:
Failed to create snapshot: Support for snapshots has been removed.

IgnoreOnSnaphost settings are warned about and ignored:
Support for option IgnoreOnSnapshot= has been removed and it is ignored

http://lists.freedesktop.org/archives/systemd-devel/2015-November/034872.html

1 files changed, 0 insertions, 106 deletions

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 70871cf3e6..3918d7e79b 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -4905,102 +4905,6 @@ static int set_property(int argc, char *argv[], void *userdata) {
         return 0;
 }
 
-static int snapshot(int argc, char *argv[], void *userdata) {
-        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
-        _cleanup_free_ char *n = NULL, *id = NULL;
-        const char *path;
-        sd_bus *bus;
-        int r;
-
-        polkit_agent_open_if_enabled();
-
-        if (argc > 1) {
-                r = unit_name_mangle_with_suffix(argv[1], UNIT_NAME_NOGLOB, ".snapshot", &n);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to generate unit name: %m");
-        } else {
-                n = strdup("");
-                if (!n)
-                        return log_oom();
-        }
-
-        r = acquire_bus(BUS_MANAGER, &bus);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_call_method(
-                        bus,
-                        "org.freedesktop.systemd1",
-                        "/org/freedesktop/systemd1",
-                        "org.freedesktop.systemd1.Manager",
-                        "CreateSnapshot",
-                        &error,
-                        &reply,
-                        "sb", n, false);
-        if (r < 0)
-                return log_error_errno(r, "Failed to create snapshot: %s", bus_error_message(&error, r));
-
-        r = sd_bus_message_read(reply, "o", &path);
-        if (r < 0)
-                return bus_log_parse_error(r);
-
-        r = sd_bus_get_property_string(
-                        bus,
-                        "org.freedesktop.systemd1",
-                        path,
-                        "org.freedesktop.systemd1.Unit",
-                        "Id",
-                        &error,
-                        &id);
-        if (r < 0)
-                return log_error_errno(r, "Failed to get ID of snapshot: %s", bus_error_message(&error, r));
-
-        if (!arg_quiet)
-                puts(id);
-
-        return 0;
-}
-
-static int delete_snapshot(int argc, char *argv[], void *userdata) {
-        _cleanup_strv_free_ char **names = NULL;
-        sd_bus *bus;
-        char **name;
-        int r;
-
-        polkit_agent_open_if_enabled();
-
-        r = acquire_bus(BUS_MANAGER, &bus);
-        if (r < 0)
-                return r;
-
-        r = expand_names(bus, strv_skip(argv, 1), ".snapshot", &names);
-        if (r < 0)
-                return log_error_errno(r, "Failed to expand names: %m");
-
-        STRV_FOREACH(name, names) {
-                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-                int q;
-
-                q = sd_bus_call_method(
-                                bus,
-                                "org.freedesktop.systemd1",
-                                "/org/freedesktop/systemd1",
-                                "org.freedesktop.systemd1.Manager",
-                                "RemoveSnapshot",
-                                &error,
-                                NULL,
-                                "s", *name);
-                if (q < 0) {
-                        log_error_errno(q, "Failed to remove snapshot %s: %s", *name, bus_error_message(&error, q));
-                        if (r == 0)
-                                r = q;
-                }
-        }
-
-        return r;
-}
-
 static int daemon_reload(int argc, char *argv[], void *userdata) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         const char *method;
@@ -6381,9 +6285,6 @@ static void systemctl_help(void) {
                "Job Commands:\n"
                "  list-jobs [PATTERN...]          List jobs\n"
                "  cancel [JOB...]                 Cancel all, one, or more jobs\n\n"
-               "Snapshot Commands:\n"
-               "  snapshot [NAME]                 Create a snapshot\n"
-               "  delete NAME...                  Remove one or more snapshots\n\n"
                "Environment Commands:\n"
                "  show-environment                Dump environment\n"
                "  set-environment NAME=VALUE...   Set one or more environment variables\n"
@@ -6526,11 +6427,6 @@ static void help_states(void) {
                 puts(slice_state_to_string(i));
 
         if (!arg_no_legend)
-                puts("\nAvailable snapshot unit substates:");
-        for (i = 0; i < _SNAPSHOT_STATE_MAX; i++)
-                puts(snapshot_state_to_string(i));
-
-        if (!arg_no_legend)
                 puts("\nAvailable socket unit substates:");
         for (i = 0; i < _SOCKET_STATE_MAX; i++)
                 puts(socket_state_to_string(i));
@@ -7460,8 +7356,6 @@ static int systemctl_main(int argc, char *argv[]) {
                 { "cat",                   2,        VERB_ANY, 0,            cat               },
                 { "status",                VERB_ANY, VERB_ANY, 0,            show              },
                 { "help",                  VERB_ANY, VERB_ANY, 0,            show              },
-                { "snapshot",              VERB_ANY, 2,        0,            snapshot          },
-                { "delete",                2,        VERB_ANY, 0,            delete_snapshot   },
                 { "daemon-reload",         VERB_ANY, 1,        0,            daemon_reload     },
                 { "daemon-reexec",         VERB_ANY, 1,        0,            daemon_reload     },
                 { "show-environment",      VERB_ANY, 1,        0,            show_environment  },