seatd: s6-style readiness notification support

This adds the ability to specify the number of an fd that is inherited
by the process as open. Once seatd is read to serve requests, it will
write a single newline and close the fd.
This commit is contained in:
Kenny Levinsen 2021-04-20 22:54:30 +02:00
parent d03e9d1c35
commit 312d6906ae
2 changed files with 22 additions and 1 deletions

View file

@ -13,6 +13,11 @@ seatd - A seat management daemon
*-h*
Show help message and quit.
*-n*
FD to notify readiness on. A single newline will be written and the fd
closed when seatd is ready to serve requests. This is compatible with
s6's notification protocol.
*-u <user>*
User to own the seatd socket.

View file

@ -70,6 +70,7 @@ int main(int argc, char *argv[]) {
const char *usage = "Usage: seatd [options]\n"
"\n"
" -h Show this help message\n"
" -n <fd> FD to notify readiness on\n"
" -u <user> User to own the seatd socket\n"
" -g <group> Group to own the seatd socket\n"
" -s <path> Where to create the seatd socket\n"
@ -78,9 +79,17 @@ int main(int argc, char *argv[]) {
int c;
int uid = 0, gid = 0;
int readiness = -1;
const char *socket_path = getenv("SEATD_SOCK");
while ((c = getopt(argc, argv, "vhs:g:u:")) != -1) {
while ((c = getopt(argc, argv, "vhn:s:g:u:")) != -1) {
switch (c) {
case 'n':
readiness = atoi(optarg);
if (readiness < 0) {
fprintf(stderr, "Invalid readiness fd: %s\n", optarg);
return 1;
}
break;
case 's':
socket_path = optarg;
break;
@ -149,6 +158,13 @@ int main(int argc, char *argv[]) {
log_info("seatd started");
if (readiness != -1) {
if (write(readiness, "\n", 1) == -1) {
log_errorf("Could not write readiness signal: %s\n", strerror(errno));
}
close(readiness);
}
while (server.running) {
if (poller_poll(&server.poller) == -1) {
log_errorf("Poller failed: %s", strerror(errno));