impl/prod: Embed AppEngine SDK into Context.

impl/prod: Embed AppEngine SDK into Context.

Add the AppEngine SDK Context to the Context returned by the luci/gae
Context. This has been confusing users, who believe that the returned
luci/gae service Context is suitable for AppEngine SDK use.

This includes the opportunity for some nasty mistakes if the users mix
the two SDKs, so warning messages have been added to appropriate
comments.

Fixes #63.

BUG=None
TEST=local
  - `goapp test ./impl/prod`

[iannucci, 2016-10-28 18:40:05]

iannucci@chromium.org changed reviewers:
+ iannucci@chromium.org

[iannucci, 2016-10-28 18:40:05]

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go
File impl/prod/context.go (right):

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go#newcode76
impl/prod/context.go:76: // CAUTIOUSLY and EXPERTLY. Some examples of pitfalls:
as I mentioned on the other CL, I would stress that it's only harmful when
mixing and matching services that luci/gae supports. Accessing unsupported
services is fine.

The other alternative is that we could just add wrappers for the rest of the
services.

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go#newcode85
impl/prod/context.go:85: //	  corruption issues.
data corruption. not really memory corruption.

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go#newcode87
impl/prod/context.go:87: return setupAECtx(appengine.WithContext(c, r))
why is setupAECtx still needed at all?

[dnj, 2016-10-29 00:11:00]

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go
File impl/prod/context.go (right):

https://codereview.chromium.org/2460803003/diff/1/impl/prod/context.go#newcode87
impl/prod/context.go:87: return setupAECtx(appengine.WithContext(c, r))
On 2016/10/28 18:40:05, iannucci wrote:
> why is setupAECtx still needed at all?

UseRemote still uses it.

[dnj, 2016-10-31 16:43:54]

Description was changed from

==========
impl/prod: Embed AppEngine SDK into Context.

Add the AppEngine SDK Context to the Context returned by the luci/gae
Context. This has been confusing users, who believe that the returned
luci/gae service Context is suitable for AppEngine SDK use.

This includes the opportunity for some nasty mistakes if the users mix
the two SDKs, so warning messages have been added to appropriate
comments.

Fixes #63.

BUG=None
TEST=local
  - `goapp test ./impl/prod`
==========

to

==========
impl/prod: Embed AppEngine SDK into Context.

Add the AppEngine SDK Context to the Context returned by the luci/gae
Context. This has been confusing users, who believe that the returned
luci/gae service Context is suitable for AppEngine SDK use.

This includes the opportunity for some nasty mistakes if the users mix
the two SDKs, so warning messages have been added to appropriate
comments.

Fixes #63.

BUG=None
TEST=local
  - `goapp test ./impl/prod`
==========