Upstart issues
From Linux-VServer
running an upstart based guest
currently upstart based guests need some manual tweaking to make them work inside a vserver guest.
I made a initpost-file (http://paste.linux-vserver.org/16021) to be used when creating hosts, so there's no need for manual tweaking. Put it in /usr/lib/util-vserver/distributions/lucid (this is not tested on anything else)
Prepare the host
First of all you need to set the init style of your vserver to plain
# echo plain > /etc/vservers/<vservername>/apps/init/style
Or use '--initstyle plain' when creating the host.
I'd also strongly recommend to mount /var/run and /var/lock of the guest as tmpfs. So add the following lines to
/etc/vservers/<vservername>/fstab
none /var/run tmpfs size=16m,nosuid,mode=0755 0 0 none /var/lock tmpfs size=16m,noexec,nosuid,nodev 0 0
remove low level services inside the guest
Then you need to get rid of anything in /etc/init/ that tries to fiddle with your Server's Hardware or other low-level Stuff that's already handled by your host's kernel/system. Having one such scriptlet still enabled might cause the whole upstart system to fail (like not beeing able to open /dev/console or failing to start the udev system).
Just remove these scriptlets, move them out of the way or rename them to something not ending in .conf. Be aware that upstart also parses subfolders of /etc/init/ for .conf files.
This is what I deleted on a basic Ubuntu 9.10 guest:
dmesg.conf hostname.conf hwclock-save.conf hwclock.conf mountall-net.conf mountall-reboot.conf mountall-shell.conf mountall.conf network-interface.conf networking.conf procps.conf rsyslog-kmsg.conf tty1.conf tty2.conf tty3.conf tty4.conf tty5.conf tty6.conf upstart-udev-bridge.conf
In Ubuntu 10.04 you also want to remove:
console-setup.conf
Services you want to look over
There are files in the /etc/init dir that you want to check the startup line of. It could be waiting for something that will never happend since it is in a VServer and thus never start.
for example mysql.conf needs a 'net-device-up'-emit also. by running
vserver <name> exec initctl emit net-device-up
it will come up like a charm. Either put this in vserver.conf or remove in from mysql.conf.
Jobs that doesn't start from scratch:
mysql-server-5.1 (mysql.conf)
Fake low level events inside the guest
Finally you need to fake emit the events that some of these scripts would do during regular boot. Probably the cleanest approach is to add a scriptlet vserver.conf to /etc/init/ with this content:
start on startup
script
touch /var/run/utmp
chown root:utmp /var/run/utmp
chmod 664 /var/run/utmp
initctl emit virtual-filesystems
initctl emit local-filesystems
initctl emit remote-filesystems
initctl emit filesystem
end script
The utmp stuff is needed if you mount /var/run as tmpfs and you don't create utmp anywhere else.
Remove console outputs
If your VServer hangs on the command
vserver <name> stop
and puts out
A timeout occured while waiting for the vserver to finish and it will be killed by sending a SIGKILL signal. The following process list might be useful for finding out the reason of this behavior: ---------------------------------------------------------------------- <pid> <context> <name> ? Ss 0:00 /sbin/init <pid> <context> <name> ? Ss 0:00 /sbin/init ----------------------------------------------------------------------
you should run
sed -i 's/^\(console output\)$/#\1/1' /etc/vservers/$name/vdir/etc/init/*
which will disable all lines with 'console output', and Upstart won't try output to it. Which is a good thing since it doesn't exist.
Adapt /etc/init/rc-sysinit.conf inside the guest
This depends on net-device-up IFACE=lo, remove this from the start line so that it reads:
start on filesystem
This scriptlet tries to parse /proc/cmdline which will not work and probably isn't needed inside a vserver.
Simply comment out or delete the whole for ARG in $(cat /proc/cmdline) do...done loop.
Notes for debugging
First you need to run Upstart with the --debug flag, one way of doing it is inserting
"--debug" in INITCMD_START under the xplain-clause inside /usr/lib/util-vserver/vserver.functions (row 316 here) so it reads INITCMD_START=( /sbin/init "--debug" )
Second you should enable console output in the rc-files inside /etc/init, if you had commented them out before you could do
sed -i 's/#^\(console output\)$/\1/1' /etc/vservers/$name/vdir/etc/init/*
Third you need a device to act as console, I used tty0.
cp -a /dev/tty0 /etc/vservers/$name/vdir/dev/console
If you do things at a console of the machine it will now print out detailed information. More on how to debug a Upstart job you'll find on http://upstart.ubuntu.com/wiki/Debugging. Notice that if one fails they all fail.
Notes for older kernels
If you encounter upstart errors like this:
$ vserver foo start init: missing runlevel Try `init --help' for more information.
or
$ vserver foo start telinit: Failed to connect to socket /com/ubuntu/upstart: Connection refused
then you're probably running the current stable version 2.6.22.19-vs2.2.0.7.
Upstart's /sbin/init implementation requires to be PID 1. It is linked against NPTL (in contrast to sysvinit), which has a bug in it's caching getpid(2) wrapper. With this kernel version getpid(2) returns the cached PID to init, resulting in init replacing itself with telinit. You can fix this by upgrading to a 2.6.26+ kernel and a newer vserver patch, or by patching upstart:
diff --git a/init/main.c b/init/main.c
index bfcd528..c6c9304 100644
--- a/init/main.c
+++ b/init/main.c
@@ -37,6 +37,7 @@
#include <string.h>
#include <syslog.h>
#include <unistd.h>
+#include <syscall.h>
#include <linux/kd.h>
@@ -131,7 +132,7 @@ main (int argc,
}
/* Check we're process #1 */
- if (getpid () > 1) {
+ if (syscall(SYS_getpid) > 1) {
execv (TELINIT, argv);
/* Ignore failure, probably just that telinit doesn't exist */
For more information see the man pages of getpid(2) (NOTES) and clone(2) (BUGS).
Init procedure doesn't complete
If you've completed all above steps and some init scripts doesn't get invoked at all (most notably old SYSV init scripts) you might have encountered same error that I did. In Lucid guest I had to comment out following line in /etc/init/ssh.conf:
# replaces SSHD_OOM_ADJUST in /etc/default/ssh oom never
to
# replaces SSHD_OOM_ADJUST in /etc/default/ssh #oom never
After commenting out this line initialization completed successfully.
