exec: Add support for env STATE_DIRECTORY

Image mode recommendation is to not ship /var/lib subdirectories if
possible and bootc lint produces warning if not. This was the case
also for Corosync.

Simplest possible solution seems to implement support for systemd
unit StateDirectory functionality and not ship /var/lib/corosync
in rpm.

So patch:
1. Adds support for reading the environment variable STATE_DIRECTORY
   which is set by systemd and use it as a default value for
   system.state_dir configuration option. This is generally useful
   feature even for non-systemd builds.
2. Set StateDirectory in service file
3. Drop /var/lib/corosync directory from RPM for systemd builds

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Christine Caulfield <ccaulfie@redhat.com>

corosync.spec.in

@@ -207,7 +207,9 @@ fi
 %{_initrddir}/corosync
 %{_initrddir}/corosync-notifyd
 %endif
+%if %{without systemd}
 %dir %{_localstatedir}/lib/corosync
+%endif
 %dir %{_localstatedir}/log/cluster
 %{_mandir}/man7/corosync_overview.7*
 %{_mandir}/man8/corosync.8*

exec/util.c

@@ -174,13 +174,24 @@ int cs_name_tisEqual (cs_name_t *str1, char *str2) {
 const char *get_state_dir(void)
 {
 	static char path[PATH_MAX] = {'\0'};
-	char *cmap_state_dir;
+	char *state_dir;
 	int res;
 
 	if (path[0] == '\0') {
-		if (icmap_get_string("system.state_dir", &cmap_state_dir) == CS_OK) {
-			res = snprintf(path, PATH_MAX, "%s", cmap_state_dir);
-			free(cmap_state_dir);
+		if (icmap_get_string("system.state_dir", &state_dir) == CS_OK) {
+			res = snprintf(path, PATH_MAX, "%s", state_dir);
+			free(state_dir);
+		} else if ((state_dir = getenv("STATE_DIRECTORY")) != NULL) {
+			/*
+			 * systemd allows multiple directory names that are
+			 * passed to env variable separated by colon. Support for this feature
+			 * is deliberately not implemented because corosync always
+			 * uses just one state directory and it is unclear what behavior should
+			 * be taken for multiple ones. If reasonable need for
+			 * supporting multiple directories appear, it must be implemented also
+			 * for cmap.
+			 */
+			res = snprintf(path, PATH_MAX, "%s", state_dir);
 		} else {
 			res = snprintf(path, PATH_MAX, "%s/%s", LOCALSTATEDIR, "lib/corosync");
 		}

init/corosync.service.in

@@ -9,6 +9,7 @@ After=network-online.target
 EnvironmentFile=-@INITCONFIGDIR@/corosync
 ExecStart=@SBINDIR@/corosync -f $COROSYNC_OPTIONS
 ExecStop=@SBINDIR@/corosync-cfgtool -H --force
+StateDirectory=corosync
 Type=notify
 
 # In typical systemd deployments, both standard outputs are forwarded to

man/corosync.conf.5

@@ -32,7 +32,7 @@
 .\" * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 .\" * THE POSSIBILITY OF SUCH DAMAGE.
 .\" */
-.TH COROSYNC_CONF 5 2025-05-13 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual"
+.TH COROSYNC_CONF 5 2025-06-12 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual"
 .SH NAME
 corosync.conf - corosync executive configuration file
 
@@ -900,7 +900,7 @@ state_dir
 Existing directory where corosync should chdir into. Corosync stores
 important state files and blackboxes there.
 
-The default is /var/lib/corosync.
+The default is the value of the environment variable STATE_DIRECTORY or /var/lib/corosync.
 
 .PP
 Within the