On 10/05/2015 02:31 AM, Antonio Terceiro wrote: > On Sun, Oct 04, 2015 at 11:19:15PM +0200, Christian Seiler wrote: >> I've attached a patch that does the following: >> >> - if /etc/inittab exists, nothing changes >> >> - if /etc/inittab doesn't exist, /etc/inittab.tail is created instead, >> and an init script is installed that will update /etc/inittab >> and append the /etc/inittab.tail file once it's booted under >> sysvinit for the first time (will do nothing under systemd) >> >> I've successfully tested it on my system. > > I do not think vmdebootstrap should carry this kind of complexity. Is > there a reason why you can't just test your package against different > images, each with its own initial setup? If you do this, even your test > code will be simpler and you don't need to do this dance.
Well, the problem is the way autopkgtest works: you don't get to define your image. If you look at the spec [1], you add a file called debian/tests/control, where you define which tests exist. Some tests may require a higher isolation level, which you can specify as a requirement. If you specify isolation-machine, your tests get started in a VM. You don't control the image and its configuration, that's part of the external testing environment. You can, however, control what's going to be installed in that system (i.e. which packages should be there). Now I could of course work around this by manually fixing stuff inside the test, but I don't think that's something I should do. The test only wants to install the other init system (sysvinit-core in this case), then reboot and perform the test itself. The test _can't_ really know what kind of configuration the VM is supposed to have to properly talk to the test environment, that's not the test's job. On the other hand, the test environment can't know that a test installs sysvinit-core inside the VM, so it can't really know that it needs to do something to make it work. The root cause I see here is that sysvinit doesn't support drop-ins a la /etc/inittab.d/ (similar to /etc/network/interfaces.d/). If that were the case, vmdebootstrap could simply just drop in a configuration snippet there and it would just work. The problem here is that I just don't see that anyone is really interested in improving sysvinit, so I wouldn't get my hopes up that this might be a reality. Whereas on the other hand vmdebootstrap advertises that it can make the VM use a serial console. But then you suddenly install a widely used package and on the next boot the serial console is just gone. (I'm going to assume that you agree not to create the file if it doesn't exist.) I don't think that's what people would expect. I would argue that it's the responsibility of the program making configuration changes to make sure they are robust. In an ideal world, that'd be something like /etc/inittab.d/serial-console - but that doesn't work, so we've got to work with what we've got. Of course, alternatively vmdebootstrap could write out a full /etc/inittab in case it doesn't exist yet. Then the problem would also go away. Btw. I had attached a wrong patch to the bug report (old version), I've added the correct one for the record. Regards, Christian [1] http://anonscm.debian.org/gitweb/?p=autopkgtest/autopkgtest.git;a=blob_plain;f=doc/README.package-tests.rst;hb=HEAD
From d257a316bfa303c66a16410689eba3fdd0ff346e Mon Sep 17 00:00:00 2001
From: Christian Seiler <christ...@iwakd.de>
Date: Sun, 4 Oct 2015 23:16:28 +0200
Subject: [PATCH] Defer modification of /etc/inittab until sysvinit is install
(if ever)
If vmdebootstrap creates /etc/inittab (in case sysvinit is not in the
initial package list), don't create it (because it's a conffile and
then will only contain the additions, not the default settings that are
required to make the system boot), but rather defer the modification of
/etc/inittab to an init script that's run when the system is booted
under sysvinit.
---
vmdebootstrap | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/vmdebootstrap b/vmdebootstrap
index 67ea2c8..452ac9b 100755
--- a/vmdebootstrap
+++ b/vmdebootstrap
@@ -828,6 +828,55 @@ class VmDebootstrap(cliapp.Application): # pylint: disable=too-many-public-meth
serial_command = self.settings['serial-console-command']
logging.debug('adding getty to serial console')
inittab = os.path.join(rootdir, 'etc/inittab')
+ if not os.path.exists(inittab):
+ # sysvinit is not installed, but might be installed later
+ # install an init script that's run at boot that will
+ # make the modifications later
+ script = os.path.join(rootdir, 'etc/init.d/local-update-inittab')
+ with open(script, 'w') as f:
+ f.write("""#! /bin/sh
+### BEGIN INIT INFO
+# Provides: local-update-inittab
+# Required-Start: $remote_fs
+# Required-Stop:
+# Default-Start: 2 3
+# Default-Stop:
+# Short-Description: Update /etc/inittab
+### END INIT INFO
+PATH=/sbin:/usr/sbin:/bin:/usr/bin
+. /lib/init/vars.sh
+. /lib/lsb/init-functions
+[ -f /etc/inittab ] || exit 0
+[ -f /etc/inittab.tail ] || exit 0
+if [ "$1" = "start" ] ; then
+ cat /etc/inittab.tail >> /etc/inittab
+ rm -f /etc/inittab.tail
+ # we need to reload init to make sure it
+ # picks up the changes to /etc/inittab
+ telinit q
+fi
+if [ "$1" = "stop" ] || [ "$1" = "status" ] ; then
+ exit 0
+fi
+echo "Error: argument '$1' not supported" >&2
+exit 3
+""")
+ os.chmod(script, 0o755)
+
+ # mask the corresponding systemd service
+ service = os.path.join(rootdir, 'etc/systemd/system',
+ 'local-update-inittab.service')
+ os.symlink('/dev/null', service)
+
+ # enable the service
+ self.runcmd(['chroot', rootdir, 'update-rc.d',
+ 'local-update-inittab', 'defaults'])
+
+ # now append the line to /etc/inittab_tail
+ # so that the init script will pick it up
+ # when first booted with sysvinit
+ inittab = os.path.join(rootdir, 'etc/inittab.tail')
+
# to autologin, serial_command can contain '-a root'
with open(inittab, 'a') as f:
f.write('\nS0:23:respawn:%s\n' % serial_command)
--
2.1.4
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