What is the best way to label all lab machines?

It's sufficient to add a properly implemented Label subclass
into server/hosts/cros_label.py.  The label detection and update
happens with every call to verify(), which happens before every
test.

... Strictly speaking, the preferred change would be to add a
new module with the Label subclasses you need, and then hook
them into the CROS_LABELS list in cros_label.py.

Ping me for questions, you'll probably want to create some akin to the os label.

https://cs.corp.google.com/chromeos_public/src/third_party/autotest/files/server/hosts/common_label.py?rcl=e1aeb2ea84d9387273a154df52d63fea43a8d026&l=12

Add me as a reviewer and I'll make sure all the bits are in the right places.

Thanks, Kevin! Will ping you for sure for any help on this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/98e696fdab73699ddb60dcdf58e6b92a7bba4213

commit 98e696fdab73699ddb60dcdf58e6b92a7bba4213
Author: Rohit Makasana <rohitbm@chromium.org>
Date: Sat Jun 04 01:48:10 2016

cros_host: Add an API to get DUT arch and CTS ABI.

This change is needed to avoid running x86 CTS bundles on ARM DUTs.

BUG= chromium:618509 
TEST=Ran cheets_CTS on veyron_minnie-cheets and cyan_cheets.

Change-Id: If961edf66a0db20567def88169a223423af27ff5
Reviewed-on: https://chromium-review.googlesource.com/349731
Trybot-Ready: Ilja H. Friedel <ihf@chromium.org>
Tested-by: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Rohit Makasana <rohitbm@chromium.org>
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Commit-Queue: Ilja H. Friedel <ihf@chromium.org>

[modify] https://crrev.com/98e696fdab73699ddb60dcdf58e6b92a7bba4213/server/hosts/cros_host.py

I have the Cl ready but due to b/29163543, I can't test it easily. Trying to find an alternative.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/5a153501a7c82ff8a16f607ed14a03aec2d094b1

commit 5a153501a7c82ff8a16f607ed14a03aec2d094b1
Author: Rohit Makasana <rohitbm@chromium.org>
Date: Mon Jun 13 22:50:09 2016

Add label detector for CTS abi

TEST=autotest/files/contrib$ ./print_host_labels.py <IP>
BUG= chromium:618509 

Change-Id: I0b9a4fb984f2d18aa0a9979e0e9ff6597b99ee5b
Reviewed-on: https://chromium-review.googlesource.com/352281
Commit-Ready: Rohit Makasana <rohitbm@chromium.org>
Tested-by: Rohit Makasana <rohitbm@chromium.org>
Reviewed-by: Kevin Cheng <kevcheng@chromium.org>

[modify] https://crrev.com/5a153501a7c82ff8a16f607ed14a03aec2d094b1/server/hosts/cros_host.py
[modify] https://crrev.com/5a153501a7c82ff8a16f607ed14a03aec2d094b1/server/hosts/cros_label.py

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chromeos/autotest-cheets/+/66551ea42178aaf36940d8c2345dab6c6265782d

commit 66551ea42178aaf36940d8c2345dab6c6265782d
Author: Ilja H. Friedel <ihf@chromium.org>
Date: Tue Jun 14 22:14:07 2016

...The label detection and update
happens with every call to verify(), which happens before every
test.

Does the label detection call depend upon the test dependency in any way? I am seeing cts_abi_* labels are still not applied. 

The label detection works as advertised; there's no dependency
on the tests.  However, the change won't take effect until there's
a push to prod.  I believe that's underway now.

Thanks for the details, Richard!

Closing... please feel free to reopen if its not fixed.