Propagate name of system service account to the bot.

Propagate name of system service account to the bot.

So it can (in later CLs) setup LUCI_CONTEXT that has this account enabled (
if it is indeed enabled).

R=iannucci@chromium.org
BUG=730878
Review-Url: https://codereview.chromium.org/2958853002
Committed: https://github.com/luci/luci-py/commit/93c2cd911054658150e1a4009bd19790d06ea62a

[Vadim Sh., 2017-06-26 23:01:49]

PTAL

A bit of plumbing. Bots needs to know what system service account (if any) is
assigned to it, so it can setup proper LUCI_CONTEXT when starting the task.

We already had this logic for default account. Extending it to support different
flavors of accounts ('task' vs 'system').

Note that we don't care about backward compatibility of /poll protocol because
bots get "locked" to a server version they were fetched from. Once this is
deployed, old bots will just receive an upgrade command, and then will start
with new code that understands new protocol.

[Vadim Sh., 2017-06-26 23:04:48]

The CQ bit was checked by vadimsh@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-06-26 23:04:55]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Vadim Sh., 2017-06-26 23:05:49]

If you are wondering about use of 'none': it all eventually comes from
Datastore's inability to index None values. So we use literal 'none' instead in
the datastore (and everywhere else for consistency).

[commit-bot: I haz the power, 2017-06-26 23:09:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-06-26 23:09:05]

Dry run: This issue passed the CQ dry run.

[iannucci, 2017-06-26 23:11:01]

lgtm

[Vadim Sh., 2017-06-26 23:14:03]

The CQ bit was checked by vadimsh@chromium.org

[commit-bot: I haz the power, 2017-06-26 23:14:05]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-26 23:21:54]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1498518843946260, "parent_rev":
"973ead8aa8bc76bb2d171873f6a6de4d1f5acff6", "commit_rev":
"93c2cd911054658150e1a4009bd19790d06ea62a"}

[commit-bot: I haz the power, 2017-06-26 23:21:59]

Description was changed from

==========
Propagate name of system service account to the bot.

So it can (in later CLs) setup LUCI_CONTEXT that has this account enabled (
if it is indeed enabled).

R=iannucci@chromium.org
BUG=730878
==========

to

==========
Propagate name of system service account to the bot.

So it can (in later CLs) setup LUCI_CONTEXT that has this account enabled (
if it is indeed enabled).

R=iannucci@chromium.org
BUG=730878

Review-Url: https://codereview.chromium.org/2958853002
Committed:
https://github.com/luci/luci-py/commit/93c2cd911054658150e1a4009bd19790d06ea62a
==========

[commit-bot: I haz the power, 2017-06-26 23:22:00]

Committed patchset #1 (id:1) as
https://github.com/luci/luci-py/commit/93c2cd911054658150e1a4009bd19790d06ea62a