From: William Lallemand <wlallemand@haproxy.com>
Date: Wed, 4 Jul 2018 13:31:23 +0000 (+0200)
Subject: MINOR: startup: change session/process group settings
X-Git-Tag: v1.9-dev1~181
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bfd8eb590908f1f326d3da214197f0fff7788435;p=thirdparty%2Fhaproxy.git

MINOR: startup: change session/process group settings

Change the way the process groups are set. Indeed setsid() was called
for every processes which caused the worker to have a different process
group than the master.

This patch behave in a better way:

- In daemon mode only, each child do a setsid()
- In master worker + daemon mode, the setsid() is done in the master before
forking the children
- In any foreground mode, we don't do a setsid()

Could be backported in 1.8 but the master-worker mode is mostly used
with systemd which rely on cgroups so that won't affect much people.
---

diff --git a/src/haproxy.c b/src/haproxy.c
index 4101cefa1b..e19d89abfb 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2775,10 +2775,10 @@ int main(int argc, char **argv)
 				ha_alert("[%s.main()] Cannot fork.\n", argv[0]);
 				protocol_unbind_all();
 				exit(1); /* there has been an error */
-			}
-			/* parent leave to daemonize */
-			if (ret > 0)
+			} else if (ret > 0) { /* parent leave to daemonize */
 				exit(0);
+			} else /* change the process group ID in the child (master process) */
+				setsid();
 		}
 
 		if (global.mode & MODE_MWORKER) {
@@ -2880,7 +2880,6 @@ int main(int argc, char **argv)
 
 					global.mode &= ~MODE_VERBOSE;
 					global.mode |= MODE_QUIET; /* ensure that we won't say anything from now */
-					setsid();
 				}
 
 				mworker_wait();
@@ -3005,7 +3004,8 @@ int main(int argc, char **argv)
 			global.mode |= MODE_QUIET; /* ensure that we won't say anything from now */
 		}
 		pid = getpid(); /* update child's pid */
-		setsid();
+		if (!(global.mode & MODE_MWORKER)) /* in mworker mode we don't want a new pgid for the children */
+			setsid();
 		fork_poller();
 	}