Serge Hallyn [Thu, 22 May 2014 20:49:15 +0000 (15:49 -0500)]
Specially handle block device rootfs
It is not possible to mount a block device from a non-init user namespace.
Therefore if root on the host is starting a container with a uid
mapping, and the rootfs is a block device, then mount the rootfs before
we spawn the container init task.
This addresses https://github.com/lxc/lxc/issues/221
Serge Hallyn [Thu, 22 May 2014 21:53:40 +0000 (16:53 -0500)]
attach: get personality through get_config command
Newer kernels optionally disallow reading /proc/$$/personality by
non-root users. We can get the personality through the lxc command
interface, so do so.
Also try to be more consistent about personality being a signed long.
We had it as int, unsigned long, signed long throughout the code.
Serge Hallyn [Tue, 20 May 2014 16:47:17 +0000 (11:47 -0500)]
cgmanager: slow down there (don't always grab abs cgroup path)
When I converted attach and enter to using move_pid_abs, these needed
to use the new get_pid_cgroup_abs method to get an absolute path. But
for some inexplicable reason I also converted the functions which get
and set cgroup properties to use the absolute paths. These are simply
not compatible with the cgmanager set_value and get_value methods.
This breaks for instance lxc-test-cgpath.
So undo that. With this patch lxc-test-cgpath, lxc-test-autotest,
and lxc-test-concurrent once again pass in a nested container.
Serge Hallyn [Thu, 15 May 2014 14:33:18 +0000 (14:33 +0000)]
add support for nbd
backing stores supported by qemu-nbd can be attached to a nbd block
device using qemu-nbd. This user-space process (pair) stays around for
the duration of the device attachment. Obviously we want it to go away
when the container shuts down, but not before the filesystems have been
cleanly unmounted.
The device attachment is done from the task which will become the
container monitor before the container setup+init task is spawned.
That task starts in a new pid namespace to ensure that the qemu-nbd
process will be killed if need be. It sets its parent death signal
to sighup, and, on receiving sighup, attempts to do a clean
qemu-device detach, then exits. This should ensure that the
device is detached if the qemu monitor crashes or exits.
It may be worth adding a delay before the qemu-nbd is detached, but
my brief tests haven't seen any data corruption.
Only the parts required for running a nbd-backed container are
implemented here. Create, destroy, and clone are not. The first
use of this that I imagine is for people to use downloaded nbd-backed
images (like ubuntu cloud images, or anything previously used with
qemu). I imagine people will want to create/clone/destroy out of
band using qemu-img, but if I'm wrong about that we can implement
the rest later.
Because attach_block_device() is done before the bdev is initialized,
and bdev_init needs to know the nbd index so that it can mount the
filesystem, we now need to pass the lxc_conf.
file_exists() is moved to utils.c so we can use it from bdev.c
The nbd attach/detach should lay the groundwork for trivial implementation
of qed and raw images.
changelog (may 12): fix idx check at detach
changelog (may 15): generalize qcow2 to nbd
Edvinas Klovas [Sat, 10 May 2014 14:47:52 +0000 (16:47 +0200)]
archlinux template: fix lxc.root for btrfs backend
when using btrfs backend lxc-create first creates rootfs in /usr/lib/lxc/rootfs
directory before moving it to /var/lib/lxc or other directory supplied by the
command line. Archlinux template relied in $rootfs_path which made containers
created with btrfs backend have lxc.rootfs set to /usr/lib/lxc/rootfs. By using
$path instead of $rootfs_path we make sure that lxc.rootfs is always correct.
Signed-off-by: Edvinas Klovas <edvinas@pnd.io> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
On older cgmanager the support was broken. So rather than
fail container starts altogether, just keep the old lxc behavior
in this case by not using name= subsystems.
Edvinas Klovas [Sat, 3 May 2014 17:15:36 +0000 (19:15 +0200)]
archlinux template: added sigpwr handling to systemd (lxc-stop)
archlinux is using systemd and systemd's configuration does not have any
services setup to handle sigpwr hook which is sent by lxc-stop command. By
enabling sigpwr service we make sure that lxc-stop will work.
Serge Hallyn [Thu, 1 May 2014 20:27:55 +0000 (15:27 -0500)]
cgmanager: use absolute cgroup path to switch cgroups at attach
If an unprivileged user does 'lxc-start -n u1' in one
login session, followed by 'lxc-attach -n u1' in another
session, the attach will fail if the sessions are in different
cgroups. The same is true of lxc-cgroup commands.
Address this by using the GetPidCgroupAbs and MovePidAbs
which work with the containers' cgroup path relative to
the cgproxy.
Since GetPidCgroupAbs is new to api version 3 in cgmanager,
use the old method if we are on an older cgmanager.
Serge Hallyn [Fri, 2 May 2014 18:36:32 +0000 (13:36 -0500)]
cgmanager: also handle named subsystems (like name=systemd)
Read /proc/self/cgroup instead of /proc/cgroups, so as to catch
named subsystems. Otherwise the contaienrs will not be fully
moved into the container cgroups.
lxc.mount.auto: improve defaults for cgroup and cgroup-full
If the user specifies cgroup or cgroup-full without a specifier (:ro,
:rw or :mixed), this changes the behavior. Previously, these were
simple aliases for the :mixed variants; now they depend on whether the
container also has CAP_SYS_ADMIN; if it does they resolve to the :rw
variants, if it doesn't to the :mixed variants (as before).
If a container has CAP_SYS_ADMIN privileges, any filesystem can be
remounted read-write from within, so initially mounting the cgroup
filesystems partially read-only as a default creates a false sense of
security. It is better to default to full read-write mounts to show the
administrator what keeping CAP_SYS_ADMIN entails.
If an administrator really wants both CAP_SYS_ADMIN and the :mixed
variant of cgroup or cgroup-full automatic mounts, they can still
specify that explicitly; this commit just changes the default without
specifier.
Currently, setup_caps and dropcaps_except both use the same parsing
logic for parsing capabilities (try to identify by name, but allow
numerical specification). Since this is a common routine, separate it
out to improve maintainability and reuseability.
Signed-off-by: Christian Seiler <christian@iwakd.de> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Ubuntu containers have had trouble with automatic cgroup mounting that
was not read-write (i.e. lxc.mount.auto = cgroup{,-full}:{ro,mixed}) in
containers without CAP_SYS_ADMIN. Ubuntu's mountall program reads
/lib/init/fstab, which contains an entry for /sys/fs/cgroup. Since
there is no ro option specified for that filesystem, mountall will try
to remount it readwrite if it is already mounted. Without
CAP_SYS_ADMIN, that fails and mountall will interrupt boot and wait for
user input on whether to proceed anyway or to manually fix it,
effectively hanging container bootup.
This patch makes sure that /sys/fs/cgroup is always a readwrite tmpfs,
but that the actual cgroup hierarchy paths (/sys/fs/cgroup/$subsystem)
are readonly if :ro or :mixed is used. This still has the desired
effect within the container (no cgroup escalation possible and programs
get errors if they try to do so anyway), while keeping Ubuntu
containers happy.
Stéphane Graber [Tue, 6 May 2014 03:34:04 +0000 (22:34 -0500)]
python-lxc: minor fixes to __init__.py
Set a base class for the network object and set the encoding in the
header. Neither of those changes are required for python3 but they do
make it easier for anyone trying to make a python2 binding.
Stéphane Graber [Mon, 5 May 2014 15:51:19 +0000 (10:51 -0500)]
lxc-ls: Force running against containers without python
When using --nesting, we exec ourselves in the container context, if we
somehow need to dynamically-load modules from there, things break. So
make sure we pre-load everything we may need.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Serge Hallyn [Fri, 2 May 2014 16:35:10 +0000 (11:35 -0500)]
cgfs: don't mount /sys/fs/cgroup readonly
/sys/fs/cgroup is just a size-limited tmpfs, and making it ro does
nothing to affect our ability alter mount settings of its subdirs.
OTOH making it ro can upset mountall in the container which tries
to remount it rw, which may be refused.
Stéphane Graber [Fri, 2 May 2014 15:16:51 +0000 (11:16 -0400)]
lxc-ls: Allow the use of --groups without --fancy
There wasn't a good reason for that limit, we can simply make the code
slightly slower when --groups is passed and still have the expected
output even without --fancy.
Stéphane Graber [Thu, 1 May 2014 22:35:21 +0000 (18:35 -0400)]
lxc-ls: Update lxc.group handling
This introduces a new -g/--group argument to filter containers based on
their groups.
This supports the rather obvious: --group blah
Which will only list containers that are in group blah.
It may also be passed multiple times: --group blah --group bleh
Which will list containers that are in either (or both) blah or bleh.
And it also takes: --group blah,bleh --group doh
Which will list containers that are either in BOTH blah and bleh or in doh.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com> Acked-by: Michael H. Warfield <mhw@WittsEnd.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
lxc-oracle: fix warnings/errors from some rpm scriptlets
- Some scriptlets expect fstab to exist so create it before doing the
yum install
- Set the rootfs selinux label same as the hosts or else the PREIN script
from initscripts will fail when running groupadd utmp, which prevents
creation of OL4.x containers on hosts > OL6.x.
- Move creation of devices into a separate function
When outputing the lxc.arch setting, use i686 instead of x86 since the
later is not a valid input to setarch, nor will the kernel output
UTS_MACHINE as x86. The kernel sets utsname.machine to i[3456]86, which
all map to PER_LINUX32.
This only converts punctuation marks from FULLWIDTH COMMA/FULL STOP to
IDEOGRAPHIC COMMA/FULL STOP in Japanese man pages. The contents of man
pages do not change at all.
When attempting to create the compulsory symlinks in /dev,
check for the existence of the link using stat first before
blindly attempting to create the link.
This works around an apparent quirk in the kernel VFS on read-only
file systems where the returned error code might be EEXIST or EROFS
depending on previous access to the /dev directory and its entries.
Reported-by: William Dauchy <william@gandi.net> Signed-off-by: Michael H. Warfield <mhw@WittsEnd.com> Tested-by: William Dauchy <william@gandi.net>
Originally we kept snapshots under /var/lib/lxcsnaps. If a
separate btrfs is mounted at /var/lib/lxc, then we can't
make btrfs snapshots under /var/lib/lxcsnaps.
This patch moves the default directory to /var/lib/lxc/lxcsnaps.
If /var/lib/lxcsnaps already exists, then use that. Don't allow
any container to be used with the name 'lxcsnaps'.
lxc startup: manually mark every shared mount entry as slave
If you 'ip netns add x1', this creates /run/netns and /run/netns/x1
as shared mounts. When a container starts, it umounts these after
pivot_root, and the umount is propagated to the host.
Worse, doing mount("", "/", NULL, MS_SLAVE|MS_REC, NULL) does not
suffice to change those, even after binding /proc/mounts onto
/etc/mtab.
So, I give up. Do this manually, walking over /proc/self/mountinfo
and changing the mount propagation on everything marked as shared.
With this patch, lxc-start no longer unmounts /run/netns/* on the
host.
This makes it so that the host doesn't need to have an old, compat
version of db43_load installed by using the db_load from the just
installed container. Some newer distributions do not even have an old
enough compat-db4 package available.
lxc-oracle: allow installing from arbitrary yum repo
With this change, you can install a container from a mounted .iso, or any
yum repo with the necessary packages. Unlike the --url option, the repo
does not need to be a mirror of public-yum, but the arch and release must
be specified. For example to install OL6.5 from an .iso image:
mount -o loop OracleLinux-R6-U5-Server-x86_64-dvd.iso /mnt
lxc-create -n OL6.5 -t oracle -- --baseurl=file:///mnt -a x86_64 -R 6.5
The template will create two yum .repo files within the container such that
additional packages can be installed from local media, or the container can
be updated from public-yum, whichever is available. Local media must be bind
mounted from the host onto the containers' /mnt for the former .repo to work:
Recent fixes in the apparmor kernel code is now making at least the CI
environment and quite possibly some others fail due to an invalid path
in the pivot_root stanza.
So update both lines to allow a more generic pivot_root call for
anything in LXC's work directory.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
In this patch I tried to stick with each file's coding style, however I
think we should probably change that. Every main() should always not
return and only exit; they should always return EXIT_SUCCESS or EXIT_FAILURE
with the only exceptions being cases where we are returning a child's
exit status (lxc_execute, lxc_attach, lxc_init).
When rebooting an unprivileged container, netpipe starts out
as not -1. If count_veths somehow changed this could lead
to trying to send data over nonexistent pipe. (Ok can't
*really* happen, as it currently stands, but it's an open
end)
Leonid Isaev [Tue, 1 Apr 2014 02:24:31 +0000 (22:24 -0400)]
archlinux: Code cleanups (v2)
Cleanups:
1. Do not modify container's /etc/hosts (archlinux uses /etc/nsswitch.conf)
2. Remove duplicate lines from config
3. Print a nicer final message
4. Get rid of some grep's
Signed-off-by: Leonid Isaev <lisaev@umail.iu.edu> Acked-by: Stéphane Graber <stgraber@ubuntu.com>
Leonid Isaev [Mon, 31 Mar 2014 21:14:34 +0000 (17:14 -0400)]
archlinux: Code cleanups
Cleanups:
1. Do not modify container's /etc/hosts (archlinux uses /etc/nsswitch.conf)
2. Remove duplicate lines from config
3. Print a nicer final message
4. Get rid of some grep's in favor of bash regex
Signed-off-by: Leonid Isaev <lisaev@umail.iu.edu> Acked-by: Stéphane Graber <stgraber@ubuntu.com>
When lxc-info's stdout is not line buffered (ie. "lxc-info -n foo |more")
the first three lines will be duplicated. This is because c->get_ips()
comes next and it forks and the child will exit() causing its fds to be
closed which flushes out its (fork duplicated) stdio buffers. The lines are
then duplicated when the parent actually gets around to flushing out its
stdio. This causes problems for programs (such as the lxc-webpanel) which
are popen()ing lxc-info.
The fix here isn't necessarily the right one, but does show what the
problem is. Seems like maybe we should fix this inside of get_ips(), for
other API callers as well.
Allow writes to kernel.shm*, net.*, kernel/domainname and
kernel/hostname,
Also fix a bug in the lxc-generate-aa-rules.py script in a
path which wasn't being exercised before, which returned a
path element rather than its child.
This should help it run better on slow test environment like the LXC CI
armhf builder.
- Wait longer for the container to start
- Wait longer for the container to shutdown
- On failure to shutdown, kill the container
- Always destroy the container if it's around
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
projects / mirror_lxc.git / log