maruel, should I completely switch from components.datastore_utils.config.GlobalConfig to components.config, or leave support for GlobalConfig in code? Only one will be used on one instance at a time.

I think CIA is still able to work without luci-config (but we crappy UI).

The reason swarming needs luci-config integration is that we want to store (platform, bitness, cipd client package name, version?) tulpes to determine which cipd version to install. I don't want to build HTML ui for modifying these settings when we have luci-config for involved configs.

I prefer a complete switch.

Ok.

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infradata/config.git/+/19bbc19fcb9a56a227f2c5d2d85bd3173dd7dd58

commit 19bbc19fcb9a56a227f2c5d2d85bd3173dd7dd58
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Apr 27 17:37:37 2016

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infradata/config.git/+/efacc675e45a8fb63dfa6451286b2c3009dd609e

commit efacc675e45a8fb63dfa6451286b2c3009dd609e
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Apr 27 17:51:03 2016

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infradata/config.git/+/9382b5da50815b68b192f3d842e05242293ee758

commit 9382b5da50815b68b192f3d842e05242293ee758
Author: Nodir Turakulov <nodir@google.com>
Date: Wed Apr 27 20:57:47 2016

The following revision refers to this bug:
  https://chromium.googlesource.com/external/github.com/luci/luci-py.git/+/fd161432f88fcfa251372ca3e1a3e45c49d24216

commit fd161432f88fcfa251372ca3e1a3e45c49d24216
Author: nodir <nodir@chromium.org>
Date: Wed Apr 27 21:25:19 2016

swarming: read configs from luci-config

- add proto/config.proto with SettingsCfg message that has same field as
  GlobalConfig.
- add a cron job that updates settings.cfg in the background.
- add ConfigApi so we can specify hostname of config service in a
  particular swarming instance.
- update config.py to read settings using components.config instead of
  GlobalConfig entity. Remove GlobalConfig.
- update handlers.py and restricted_config.html accordingly
  Remove code related to config mutation.

R=maruel@chromium.org, vadimsh@chromium.org
BUG= 601018 

Review-Url: https://codereview.chromium.org/1926443003

[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/components/components/config/api.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/components/components/config/common.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/components/components/config/remote.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/app.yaml
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/cron.yaml
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/handlers_frontend.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/handlers_test.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/main.py
[add] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/proto/Makefile
[add] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/proto/__init__.py
[add] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/proto/config.proto
[add] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/proto/config_pb2.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/server/config.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/server/task_scheduler_test.py
[modify] https://crrev.com/fd161432f88fcfa251372ca3e1a3e45c49d24216/appengine/swarming/templates/restricted_config.html

The following revision refers to this bug:
  https://chromium.googlesource.com/external/github.com/luci/luci-py.git/+/e0b5e052ef4cf2472ce9a62feff33296ca588d8e

commit e0b5e052ef4cf2472ce9a62feff33296ca588d8e
Author: nodir <nodir@chromium.org>
Date: Wed Apr 27 22:01:20 2016

swarming: cache settings in main memory

R=maruel@chromium.org
BUG= 601018 

Review-Url: https://codereview.chromium.org/1922073005

[modify] https://crrev.com/e0b5e052ef4cf2472ce9a62feff33296ca588d8e/appengine/swarming/server/config.py

Integration is complete. Changes are deployed. Database is cleaned up from old GlobalConfig* entities

The following revision refers to this bug:
  https://chromium.googlesource.com/external/github.com/luci/luci-py.git/+/72663d0ab37cdbcfabf29830d08eb7bc7e345009

commit 72663d0ab37cdbcfabf29830d08eb7bc7e345009
Author: nodir <nodir@chromium.org>
Date: Thu Apr 28 15:45:39 2016

swarming: update comment since GlobalConfig remove

TBR=maruel@chromium.org
BUG= 601018 

Review-Url: https://codereview.chromium.org/1929033002

[modify] https://crrev.com/72663d0ab37cdbcfabf29830d08eb7bc7e345009/appengine/swarming/server/task_scheduler_test.py

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infradata/config.git/+/1f8e6155e3b37811f514f4012af5b02304496d90

commit 1f8e6155e3b37811f514f4012af5b02304496d90
Author: Nodir Turakulov <nodir@google.com>
Date: Thu May 05 16:59:08 2016