Hosts without support for lxc-attach are ancien and can always use old
versions of vagrant-lxc. To be able to move forward more easily, we
should be able to assume a functional `lxc-attach`.
As for `/sbin/halt`, I'm really not sure it's needed anymore. Let's see
if its removal causes problems.
LXC 3.0, unlike 2.1, doesn't support old configuration formats at all
and because our previous approach to handling old format was incomplete,
running `vagrant up` on a system with LXC 3.0 would fail, even if the
base box itself was made with modernized config.
This commit fixes this problem: is the box has a modern config, it's
going to be properly created and booted under LXC 3.0. It does so
without breaking the support for LXC < 2.1
When running with LXC 2.1+, ensure that our boxes have up-to-date config
keys by running the `lxc-update-config` utility that ships with LXC
2.1+.
When the command doesn't exist (LXC <2.1), we do nothing.
ref #445
`lxc-info -iH` to retrieve IP address was not available in early LXC
development but was there at LXC 1.0. Because we've bumped our minimum
LXC requirement to v1.0 recently, we can simplify the IP retrieval
process and also get rid of the `dnsmasq` fallback.
* for lxc to 1.0.0 using constant Vagrant::LXC::Driver::DEFAULT_CONTAINERS_PATH
* change method Vagrant::LXC::Driver::CLI#version to call lxc-create if lxc-version command not exists (to lxc version 1.0.0)
Some platforms (most notably CentOS and RHEL) use a kernel without
'attach' support. This patch detects this absence and falls back
to the alternative ways of doing things like detection of IP address
and halting the container.
It does so by running the command "true" through lxc-attach.
