Fixed issue involving alternate users being set in
the image's Dockerfile.

Fixed issue with accurate permissions to run runit service.

Fixed issue with quotes to properly handle sh commands.

Fixed issue where Docker images based on scratch are not in
an array like other Docker images, so config attributes are
preserved.

Modified the analyze script that if it sees a debian
without a version, it should update it to debianS.
Then added a symlink that points debianS to debian9.
This with some other changes David made should result
in functioning support of debian:sid in Docker

Squashed commit of the following:

commit 7af0b39c
Merge: dff5441d 9b7e1a39
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 9 13:07:22 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit dff5441d
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 9 11:24:14 2018 -0600

    Adding support for debian sid

commit 5b4e102b
Merge: ef1f1102 34aa0d23
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 19:18:13 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit ef1f1102
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 16:42:12 2018 -0600

    Removed ubuntu18 references

commit ecded73c
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 16:40:59 2018 -0600

    Adding missing suppress flags for install

commit 42358979
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 14:49:10 2018 -0600

    Fixing bad fd issue with libssl install

commit 40528b13
Merge: a8061efe e468cc49
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 12:58:40 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit a8061efe
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 09:53:55 2018 -0600

    Update path reference to ubuntu18

commit 4305ad26
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 09:42:10 2018 -0600

    Adding support for ubuntu 18.04 lts

commit e21c64a3
Merge: 9ed6c0e5 642d15f8
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Tue May 8 08:41:09 2018 -0600

    Merge remote-tracking branch 'upstream/master' into entrypoint-bug-fix

commit 9ed6c0e5
Merge: 7fdb8351 ee3694f4
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 22:27:03 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit 7fdb8351
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 17:56:16 2018 -0600

    Reorganizing user account support for cmd/entrypoint

commit 608afa03
Merge: 44c4ca77 faf2368f
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 17:10:22 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit 44c4ca77
Merge: fe063cc2 186c6b7b
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 16:19:47 2018 -0600

    Merge branch 'master' into entrypoint-bug-fix

commit fe063cc2
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 16:17:31 2018 -0600

    Persist environment variables

commit 8c8e206d
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Mon May 7 15:55:00 2018 -0600

    Adding support for dockerfiles that use alt users

commit d6082d11
Merge: f5a5b0e4 d633f6a2
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Fri May 4 10:54:00 2018 -0600

    Merge remote-tracking branch 'origin/master' into entrypoint-bug-fix

commit f5a5b0e4
Merge: 6ef666cd 0bf7e0b3
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Fri May 4 00:25:20 2018 -0600

    Resolved libvnode_docker conflict

commit 6ef666cd
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Thu May 3 18:27:48 2018 -0600

    Removing debugging statements

commit 72336705
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Thu May 3 18:06:24 2018 -0600

    Fixed issue where os images aren't in an array

commit ab483221
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 2 23:49:39 2018 -0600

    more debugging

commit 88e7a74f
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 2 21:02:35 2018 -0600

    some debugging work

commit cb107aaa
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 2 17:55:08 2018 -0600

    Fixing permission issue

commit 55f07ba5
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 2 09:20:23 2018 -0600

    Forgot semicolons are a thing in perl

commit d667575e
Author: Elijah Grubb <u0894728@utah.edu>
Date:   Wed May 2 08:45:22 2018 -0600

    Fixing quotes bug

Particularly, override Entrypoint and User.

This is probably true for Xen too, but in some cases, the
vnodesetup early-release hackwaitandexit timeout of 30 seconds
causes a race condition.  Normally, the first node sets up
significant network state, and sometimes flips MAC addresses
around from interface to interface -- OR puts a physical interface
into a bridge, then changes the bridge's MAC address.  There is a
short window of time where both the bridge and the new member
interface share a MAC address -- and if the tmcc ifconfig assembly
process for vnodes following the first vnode resolves
the wrong device's MAC address and uses that to flesh out the
ifconfig info, the vnodesetup will be in a world of hurt (i.e., you
might see an attempt to make a vlan device out of a vlan device).
The chance of this happening is miniscule, but I've seen it.

So, at least for docker for now, we protect the first vnode against
the 30-second timeout in vnodesetup hackwaitandexit, and we wait for the
actual running file to be written, or error.

This is probably applicable to any linux mkvnode.pl path, but I suppose
it would have been another hundred thousand vnode creates before I saw
it again.

Under high load, of course we can have DNS problems.  However, perl
seems to get stuck on retry; it's like the nak gets cached (which would
be extremely odd, but can't argue with the evidence).

Anyway, if resolution continues to fail, give up and feed the name to
iptables, and let it try :).

(All we need to do while holding the global lock is allocated IFBs; the
generation of routing scripts and traffic shaping scripts is both
unlikely to fail and potentially slow due to running djikstra.  So, also
let the vnode early release prior to those things, immediately after IFB
allocation.)

Docker vnodes require the full image path anytime the vnode is created,
even if the image in question already exists on the vhost.  This is
because emulab custom docker images are fully-qualified with their
hosting private registry, so we need that detail even if we're not
re-pulling the image; i.e., if the vnode gets destroyed and recreated
after its initial reload.

Prior to this commit, I had reused all the libvnode:: network functions,
but that requires these system-wide indexes to be built (i.e. bridges,
ifaces) before using the helpers -- and on any network state change.
Those indexing functions take a long time on heavily-loaded systems
(i.e., 5k processes, hundreds of ifaces).  The helpers become very fast;
but for the case of large numbers of vnodes on one vhost, it is better
to hold the global lock for less time, and pay a higher per-helper cost,
instead of making use of a nicely-indexed cache.

So now we cache nothing and (hopefully) use /sys intelligently to avoid
forking unnecessarily.

and so we have to look through the image versions for each image
in the alias.

When running hundreds of containers per vhost, need a bit more
time for these.  I really need to reassess which of these is really
necessary any longer.

The docker engine API may not be available by the time bootvnodes runs;
this can happen, for instance, if many containers on the vhost and
if some had stale sandboxes.

(Also, pass vhost node attributes to rootPreConfig.)

Seems that when the host is heavily loaded, docker will mix in control
chars, etc, to the output of a container.  We try to filter as much as
possible, but sadly it's not just control chars; printable chars can
sneak through.

(linkmap, lt(p)map can all grow large on very large topos; so make
space for them.

reservations that have started (start time in the past), the date picker
was actually showing the current day instead, need an option to make it
show a date in the past.