Newer kernels have added a new restriction:  if /proc or /sys on the
host has files or non-empty directories which are over-mounted, and
there is no /proc which fully visible, then it assumes there is a
"security" reason for this.  It prevents anyone in a non-initial user
namespace from creating a new proc or sysfs mount.

To work around this, this patch adds a new 'nesting.conf' which can be
lxc.include'd from a container configuration file.  It adds a
non-overmounted mount of /proc and /sys under /dev/.lxc, so that the
kernel can see that we're not trying to *hide* things like /proc/uptime.
and /sys/devices/virtual/net.  If the host adds this to the config file
for container w1, then container w1 will support unprivileged child
containers.

The nesting.conf file also sets the apparmor profile to the with-nesting
variant, since that is required anyway.  This actually means that
supporting nesting isn't really more work than it used to be, just
different.  Instead of adding

lxc.aa_profile = lxc-container-default-with-nesting

you now just need to

lxc.include = /usr/share/lxc/config/nesting.conf

(Look, fewer characters :)

Finally, in order to maintain the current apparmor protections on
proc and sys, we make /dev/.lxc/{proc,sys} non-read/writeable.
We don't need to be able to use them, we're just showing the
kernel what's what.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Add the description of optional, create=file/dir for lxc.mount.entry.
This is update for commit f5b67b36.
Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

First, fix use of uninitialized variable 'ret'.  Then, actually use
the value it returned in its caller.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

On very busy systems, some virtual network devices won't be destroyed after a
container halts.  This patch uses the lxc_delete_network() method to ensure
that network devices attached to the container are destroyed when the
container halts.

Without the patch, some virtual network devices are left over on the system
and must be removed with `ip link del <device>`.  This caused containers
with lxc.network.veth.pair to not be able to start.  For containers using
randomly generated virtual network device names, the old devices will hang
around on the bridge with their original MAC address.
Signed-off-by: Major Hayden <major@mhtx.net>

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

"NAME for name of the container" becomes "NAME of the container"
Signed-off-by: Christian Brauner <christianvanbrauner@gmail.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

- Passing the LXC_CLONE_KEEPNAME flag to do_lxcapi_clone() was not respected and
  let to unexpected behaviour for e.g. lxc-clone. We wrap
  clear_unexp_config_line() and set_config_item_line() in an appropriate
  if-condition.
Signed-off-by: Christian Brauner <christianvanbrauner@gmail.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Signed-off-by: Nicolas Cornu <nicolac76@yahoo.fr>

Signed-off-by: Nicolas Cornu <ncornu@aldebaran.com>

Signed-off-by: Nicolas Cornu <ncornu@aldebaran.com>

Signed-off-by: Michał Grzędzicki <lazy404@gmail.com>

When setting lxc.network.veth.pair to get a fixed interface
name the recreation of it after a reboot caused an EEXIST.
-) The reboot flag is now a three-state value. It's set to
1 to request a reboot, and 2 during a reboot until after
lxc_spawn where it is reset to 0.
-) If the reboot is set (!= 0) within instantiate_veth and
a fixed name is used, the interface is now deleted before
being recreated.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

This fixes some typos, missing newlines and unflushed output leading to
duplicate entries when piped (similar to what we had in lxc-info).

Reported-by: Marc Gariépy
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>

When starting a daemonized container, only the original parent
thread should return to the caller.  The first forked child
immediately exits after forking, but the grandparent child
was in some places returning on error - causing a second instance
of the calling function.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>

The dev/mqueue and dev/shm directories do not exist when using lxc.autodev, thus they have to be created upon mount.
Signed-off-by: Dennis Schridde <devurandom@gmx.net>

In various places throughout the code, we want to "nullify" the std fds,
opening them to /dev/null or zero or so. Instead, let's unify this code and do
it in such a way that Coverity (probably) won't complain.

v2: use /dev/null for stdin as well
v3: add a comment about use of C's short circuiting
v4: axe comment, check errors on dup2, s/quiet/need_null_stdfds

Reported-by: Coverity
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

and don't use it if not. This fixes failure to build with older
cgmanager.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Doing this requires some btrfs functions from bdev to be used in
utils.c  Because utils.h is imported by lxc_init.c, I had to create
a new initutils.[ch] which are used by both lxc_init.c and utils.c
We could instead put the btrfs functions into utils.c, which would
be a shorter patch, but it really doesn't belong there.  So I went
the other way figuring there may be more such cases coming up of
fns in utils.c needing code from bdev.c which can't go into lxc_init.

Currently, if we detect a btrfs subvolume we just remove it.  The
st_dev on that dir is different, so we cannot detect if this is
bound in from another fs easily.  If we care, we should check
whether this is a mountpoint, this patch doesn't do that.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

We need to use lxc_list_for_each_safe, otherwise de-allocation
will fail with a list size bigger than 2. The pointer to the head
of the list also need freeing after we've freed all other elements
of the list.
Signed-off-by: Kien Truong <duckientruong@gmail.com>

Signed-off-by: Kien Truong <duckientruong@gmail.com>

Add a function to sort the cgroup settings before applying.
Currently, the function will put memory.memsw.limit_in_bytes after
memory.limit_in_bytes setting so the container will start
regardless of the order specified in the input. Fix #453
Signed-off-by: Kien Truong <duckientruong@gmail.com>

This is needed for lxc.autodev=1 to work.
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

If an unprivileged ephemeral container is started as follows,

    lxc-start-ephemeral -o trusty -n test_ephemeral

Then an empty directory remains upon exit from the container,

    ~/.local/share/lxc/test_ephemeral/tmpfs/delta0

(The tmpfs filesystem is successfully unmounted, but we seem to lack
permission to delete the delta0 directory).

This issue arose following commits 4799a1e7 and dd2271e6 .

The following patch resolves the issue. It has been tested on ubuntu
14.04 with the lxc-daily ppa.
Since gmail screws up the formatting of the patch via line-wrapping
etc, please copy the patch from the issue-tracker rather than from
this email.

Signed-off by: Oleg Freedholm <overlayfs@gmail.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

One of the 'features' of overlayfs is that depending on whether a file
is on the upper or lower dir you get back a different device from stat.
That breaks our lxc_rmdir_onedev.

So at lxc_rmdir_ondev check the device of the directory being deleted.
If it is overlayfs, then skip the device check.

Note this is unrelated to overlayfs snapshots - in those cases when you
delete a container, /var/lib/lxc/$container/ does not actually have an
overlayfs under it.  Rather, to reproduce this you would

sudo mkdir /opt/{lower,upper,workdir}
sudo mount -t overlayfs -o lower=/opt/lower,upper=/opt/upper,workdir=/opt/workdir \
	lxc /var/lib/lxc
sudo lxc-create -t download -n c1 -- -d ubuntu -r trusty -a amd64
sudo lxc-destroy -n c1
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Tested-by: Marko Ratkaj <marko.ratkaj@sartura.hr>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

/dev/shm needs to be mounted as tmpfs. It's needed by python
and possibly other packages.
Signed-off-by: Markos Chandras <hwoarang@gentoo.org>

Close #421
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

- document environment variables
- add missing --packages switch to command line
- describe how to pass template options to lxc-create (since
  lxc-create -h doesn't tell you)
- render help text in the same pretty format as lxc-create does
Signed-off-by: Tomáš Posíšek <tpo_deb@sourcepole.ch>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Ensures matching versions of lxc and lxc-libs being installed
Signed-off-by: Johannes Kastl <mail@ojkastl.de>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

The following functions return immediately if a null pointer was passed.
* container_destroy
* lxc_cgroup_process_info_free_and_remove
* lxc_cgroup_put_meta
* toss_list

It is therefore not needed that a function caller repeats a corresponding check.

This issue was fixed by using the software Coccinelle 1.0.0-rc23.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

The function "free" is documented in the way that no action shall occur for
a passed null pointer. It is therefore not needed that a function caller
repeats a corresponding check.
http://stackoverflow.com/questions/18775608/free-a-null-pointer-anyway-or-check-first

This issue was fixed by using the software Coccinelle 1.0.0-rc23.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

This defines a missing variable and re-indents the code a bit.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

It turns out that the new upstream overlay fs requires that the delta
and work dirs be under the same mount.  So create a $lxcpath/tmpfs
and create delta0 and work0 under that.  If the user asks for a
tmpfs that'll be mounted under $lxcpath/tmpfs and workdir and delta0
both created under that.

This isn't heavily tested.  But if fixes mounting of 'overlay' fs
for me.

It's "not backward compatible", since it moves delta0, but that
shouldn't matter since ephemeral containers are either destroyed
on exit, or re-started with lxc-start.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

We fixed this some time ago for basic lxc-start, but never did
lxc-start-ephemeral.

Since the lxc-start patches were pushed, Miklos has given us a
way to detect whether we need the workdir= option.  So the
bdev.c code could be simplified to check for "overlay\n" in
/proc/filesystems just as lxc-start-ephemeral does.  This
patch doesn't do that.

Changelog (v2):
	1. use 'overlay' fstype for new overlay upstream module
	2. avoid using unneeded readlines().
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

Signed-off-by: David Noyes <david.j.noyes@gmail.com>

Signed-off-by: David Noyes <david.j.noyes@gmail.com>

It is not an error to create a container without a template or rootfs.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

Commit 6c6892b5 "fix multithreaded create()" prevented the container
configuration from being saved if the backing store does not need
to be created.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

A container without a rootfs is useful for running a collection of
processes in separate namespaces (to provide separate networking as
an example), while sharing the host filesystem (except for specific
paths that are re-mounted as needed). For multiple processes to run
automatically when such a container is started, it can be launched
using lxc-start, and a separate instance of systemd can manage just
the processes inside the container. (This assumes that the path to
the systemd unit files is re-mounted and only contains the services
that should run inside the container.) For this use case, autodev
should be permitted for a container that does not have a rootfs.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>