LXC refactor fixes

[EvaSDK]

As requested in saltstack/salt issue saltstack#14865, I have been testing the lxc-refactor branch.

Here are a few fixes I had to apply to have a successful run of salt-call state.sls cloud.

There are two more points that are not in this PR but need to be discussed as I have no idea how to do it right now.

1. On my distribution (Gentoo), lxc configuration is located in /etc/lxc. This is fine since there is effectively only configuration files there for me but this is not configurable in Salt. How would I go about fixing that ? For now, I am just fixing it locally using sed.
2. lxc-clone is blocking salt-call with a silly question. It detects a filesystem signature on the LV after I created the silly folder for it to mount the one to clone from (which is based on LV name, not rootfs...) and asks if I want to wipe it. I haven't found a documented option to force it to proceed. It seems like echoing to fd 0 of the process made it continue but this is not ideal.

Here is the output of lxc-clone for reference:

# lxc-clone --help
Usage: lxc-clone [-s] [-B backingstore] [-L size[unit]] [-K] [-M] [-H]
          [-p lxcpath] [-P newlxcpath] orig new

  -s: snapshot rather than copy
  -B: use specified new backingstore.  Default is the same as
      the original.  Options include aufs, btrfs, lvm, overlayfs,
      dir and loop
  -L: for blockdev-backed backingstore, use specified size * specified
      unit. Default size is the size of the source blockdev, default
      unit is MB
  -K: Keep name - do not change the container name
  -M: Keep macaddr - do not choose a random new mac address
  -p: use container orig from custom lxcpath
  -P: create container new in custom lxcpath

I have only tested with a clone for now so there might be more issues than that.

[terminalmage]

Ahh, good catches.

With regards to the LVM warning, I have seen this as well I think. Are you seeing a message saying that there is already a logical volume by the desired name?

[EvaSDK]

Nope, it prints

# lxc-clone -o buildd.gentoo -n buildd.gentoo-2 -L 8G
WARNING: ext4 signature detected on /dev/seta/vm.buildd.gentoo-2 at offset 1080. Wipe it? [y/n]:

Of course output varies according to last time the blocks allocated by LVM were used for.

[EvaSDK]

Also, for the default seed value, do you have any hint why it would be unset at this point, I needed this hack to get things working but I bet there is a good explanation for this case to occur.