[RFC PATCH 3/5] maintenance: use packaged systemd units
- Remove the code writing the units
- Simplify calling systemctl
- systemctl does not error out when disabling units which aren't
enabled, nor when enabling already enabled units
- call systemctl only once, with all the units.
- Add clean-up code for leftover units in $XDG_CONFIG_HOME created by
previous versions of git, taking care of preserving actual user
override (by checking the start of the file).Signed-off-by: Max Gautier <mg@max.gautier.name>
---
builtin/gc.c | 293 ++++++++-------------------------------------------
1 file changed, 45 insertions(+), 248 deletions(-)
diff --git a/builtin/gc.c b/builtin/gc.c
index cb80ced6cb..981db8e297 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -2308,276 +2308,73 @@ static char *xdg_config_home_systemd(const char *filename)
return xdg_config_home_for("systemd/user", filename);
}
-#define SYSTEMD_UNIT_FORMAT "git-maintenance@%s.%s"
-
-static int systemd_timer_delete_timer_file(enum schedule_priority priority)
-{
- int ret = 0;
- const char *frequency = get_frequency(priority);
- char *local_timer_name = xstrfmt(SYSTEMD_UNIT_FORMAT, frequency, "timer");
- char *filename = xdg_config_home_systemd(local_timer_name);
-
- if (unlink(filename) && !is_missing_file_error(errno))
- ret = error_errno(_("failed to delete '%s'"), filename);
-
- free(filename);
- free(local_timer_name);
- return ret;
-}
-
-static int systemd_timer_delete_service_template(void)
-{
- int ret = 0;
- char *local_service_name = xstrfmt(SYSTEMD_UNIT_FORMAT, "", "service");
- char *filename = xdg_config_home_systemd(local_service_name);
- if (unlink(filename) && !is_missing_file_error(errno))
- ret = error_errno(_("failed to delete '%s'"), filename);
-
- free(filename);
- free(local_service_name);
- return ret;
-}
-
-/*
- * Write the schedule information into a git-maintenance@<schedule>.timer
- * file using a custom minute. This timer file cannot use the templating
- * system, so we generate a specific file for each.
- */
-static int systemd_timer_write_timer_file(enum schedule_priority schedule,
- int minute)
-{
- int res = -1;
- char *filename;
- FILE *file;
- const char *unit;
- char *schedule_pattern = NULL;
- const char *frequency = get_frequency(schedule);
- char *local_timer_name = xstrfmt(SYSTEMD_UNIT_FORMAT, frequency, "timer");
-
- filename = xdg_config_home_systemd(local_timer_name);
-
- if (safe_create_leading_directories(filename)) {
- error(_("failed to create directories for '%s'"), filename);
- goto error;
- }
- file = fopen_or_warn(filename, "w");
- if (!file)
- goto error;
-
- switch (schedule) {
- case SCHEDULE_HOURLY:
- schedule_pattern = xstrfmt("*-*-* 1..23:%02d:00", minute);
- break;
-
- case SCHEDULE_DAILY:
- schedule_pattern = xstrfmt("Tue..Sun *-*-* 0:%02d:00", minute);
- break;
-
- case SCHEDULE_WEEKLY:
- schedule_pattern = xstrfmt("Mon 0:%02d:00", minute);
- break;
-
- default:
- BUG("Unhandled schedule_priority");
- }
-
- unit = "# This file was created and is maintained by Git.\n"
- "# Any edits made in this file might be replaced in the future\n"
- "# by a Git command.\n"
- "\n"
- "[Unit]\n"
- "Description=Optimize Git repositories data\n"
- "\n"
- "[Timer]\n"
- "OnCalendar=%s\n"
- "Persistent=true\n"
- "\n"
- "[Install]\n"
- "WantedBy=timers.target\n";
- if (fprintf(file, unit, schedule_pattern) < 0) {
- error(_("failed to write to '%s'"), filename);
- fclose(file);
- goto error;
- }
- if (fclose(file) == EOF) {
- error_errno(_("failed to flush '%s'"), filename);
- goto error;
- }
-
- res = 0;
-
-error:
- free(schedule_pattern);
- free(local_timer_name);
- free(filename);
- return res;
-}
-
-/*
- * No matter the schedule, we use the same service and can make use of the
- * templating system. When installing git-maintenance@<schedule>.timer,
- * systemd will notice that git-maintenance@.service exists as a template
- * and will use this file and insert the <schedule> into the template at
- * the position of "%i".
- */
-static int systemd_timer_write_service_template(const char *exec_path)
-{
- int res = -1;
- char *filename;
- FILE *file;
- const char *unit;
- char *local_service_name = xstrfmt(SYSTEMD_UNIT_FORMAT, "", "service");
-
- filename = xdg_config_home_systemd(local_service_name);
- if (safe_create_leading_directories(filename)) {
- error(_("failed to create directories for '%s'"), filename);
- goto error;
- }
- file = fopen_or_warn(filename, "w");
- if (!file)
- goto error;
-
- unit = "# This file was created and is maintained by Git.\n"
- "# Any edits made in this file might be replaced in the future\n"
- "# by a Git command.\n"
- "\n"
- "[Unit]\n"
- "Description=Optimize Git repositories data\n"
- "\n"
- "[Service]\n"
- "Type=oneshot\n"
- "ExecStart=\"%s/git\" --exec-path=\"%s\" for-each-repo --config=maintenance.repo maintenance run --schedule=%%i\n"
- "LockPersonality=yes\n"
- "MemoryDenyWriteExecute=yes\n"
- "NoNewPrivileges=yes\n"
- "RestrictAddressFamilies=AF_UNIX AF_INET AF_INET6 AF_VSOCK\n"
- "RestrictNamespaces=yes\n"
- "RestrictRealtime=yes\n"
- "RestrictSUIDSGID=yes\n"
- "SystemCallArchitectures=native\n"
- "SystemCallFilter=@system-service\n";
- if (fprintf(file, unit, exec_path, exec_path) < 0) {
- error(_("failed to write to '%s'"), filename);
- fclose(file);
- goto error;
- }
- if (fclose(file) == EOF) {
- error_errno(_("failed to flush '%s'"), filename);
- goto error;
- }
-
- res = 0;
-
-error:
- free(local_service_name);
- free(filename);
- return res;
-}
-
-static int systemd_timer_enable_unit(int enable,
- enum schedule_priority schedule,
- int minute)
+static int systemd_set_units_state(int enable)
{
const char *cmd = "systemctl";
struct child_process child = CHILD_PROCESS_INIT;
- const char *frequency = get_frequency(schedule);
-
- /*
- * Disabling the systemd unit while it is already disabled makes
- * systemctl print an error.
- * Let's ignore it since it means we already are in the expected state:
- * the unit is disabled.
- *
- * On the other hand, enabling a systemd unit which is already enabled
- * produces no error.
- */
- if (!enable)
- child.no_stderr = 1;
- else if (systemd_timer_write_timer_file(schedule, minute))
- return -1;
get_schedule_cmd(&cmd, NULL);
strvec_split(&child.args, cmd);
- strvec_pushl(&child.args, "--user", enable ? "enable" : "disable",
- "--now", NULL);
- strvec_pushf(&child.args, SYSTEMD_UNIT_FORMAT, frequency, "timer");
+
+ strvec_pushl(&child.args, "--user", "--force", "--now",
+ enable ? "enable" : "disable",
+ "git-maintenance@hourly.timer",
+ "git-maintenance@daily.timer",
+ "git-maintenance@weekly.timer", NULL);
+ /*
+ ** --force override existing conflicting symlinks
+ ** We need it because the units have changed location (~/.config ->
+ ** /usr/lib)
+ */
if (start_command(&child))
return error(_("failed to start systemctl"));
if (finish_command(&child))
- /*
- * Disabling an already disabled systemd unit makes
- * systemctl fail.
- * Let's ignore this failure.
- *
- * Enabling an enabled systemd unit doesn't fail.
- */
- if (enable)
- return error(_("failed to run systemctl"));
+ return error(_("failed to run systemctl"));
return 0;
}
-/*
- * A previous version of Git wrote the timer units as template files.
- * Clean these up, if they exist.
- */
-static void systemd_timer_delete_stale_timer_templates(void)
+static void systemd_delete_user_unit(char const *unit)
{
- char *timer_template_name = xstrfmt(SYSTEMD_UNIT_FORMAT, "", "timer");
- char *filename = xdg_config_home_systemd(timer_template_name);
+ char const file_start_stale[] = "# This file was created and is"
+ " maintained by Git.";
+ char file_start_user[sizeof(file_start_stale)] = {'\0'};
+
+ char *filename = xdg_config_home_systemd(unit);
+ int handle = open(filename, O_RDONLY);
- if (unlink(filename) && !is_missing_file_error(errno))
+ /*
+ ** Check this is actually our file and we're not removing a legitimate
+ ** user override.
+ */
+ if (handle == -1 && !is_missing_file_error(errno))
warning(_("failed to delete '%s'"), filename);
+ else {
+ read(handle, file_start_user, sizeof(file_start_stale) - 1);
+ close(handle);
+ if (strcmp(file_start_stale, file_start_user) == 0) {
+ if (unlink(filename) == 0)
+ warning(_("deleted stale unit file '%s'"), filename);
+ else if (!is_missing_file_error(errno))
+ warning(_("failed to delete '%s'"), filename);
+ }
+ }
free(filename);
- free(timer_template_name);
-}
-
-static int systemd_timer_delete_unit_files(void)
-{
- systemd_timer_delete_stale_timer_templates();
-
- /* Purposefully not short-circuited to make sure all are called. */
- return systemd_timer_delete_timer_file(SCHEDULE_HOURLY) |
- systemd_timer_delete_timer_file(SCHEDULE_DAILY) |
- systemd_timer_delete_timer_file(SCHEDULE_WEEKLY) |
- systemd_timer_delete_service_template();
-}
-
-static int systemd_timer_delete_units(void)
-{
- int minute = get_random_minute();
- /* Purposefully not short-circuited to make sure all are called. */
- return systemd_timer_enable_unit(0, SCHEDULE_HOURLY, minute) |
- systemd_timer_enable_unit(0, SCHEDULE_DAILY, minute) |
- systemd_timer_enable_unit(0, SCHEDULE_WEEKLY, minute) |
- systemd_timer_delete_unit_files();
-}
-
-static int systemd_timer_setup_units(void)
-{
- int minute = get_random_minute();
- const char *exec_path = git_exec_path();
-
- int ret = systemd_timer_write_service_template(exec_path) ||
- systemd_timer_enable_unit(1, SCHEDULE_HOURLY, minute) ||
- systemd_timer_enable_unit(1, SCHEDULE_DAILY, minute) ||
- systemd_timer_enable_unit(1, SCHEDULE_WEEKLY, minute);
-
- if (ret)
- systemd_timer_delete_units();
- else
- systemd_timer_delete_stale_timer_templates();
-
- return ret;
}
static int systemd_timer_update_schedule(int run_maintenance, int fd UNUSED)
{
- if (run_maintenance)
- return systemd_timer_setup_units();
- else
- return systemd_timer_delete_units();
+ /*
+ * A previous version of Git wrote the units in the user configuration
+ * directory. Clean these up, if they exist.
+ */
+ systemd_delete_user_unit("git-maintenance@hourly.timer");
+ systemd_delete_user_unit("git-maintenance@daily.timer");
+ systemd_delete_user_unit("git-maintenance@weekly.timer");
+ systemd_delete_user_unit("git-maintenance@.timer");
+ systemd_delete_user_unit("git-maintenance@.service");
+ return systemd_set_units_state(run_maintenance);
}
enum scheduler {
--
2.44.0
Max Gautier <mg@max.gautier.name>