Update Coordinator client, add datagram assembly.

Update Coordinator client, add datagram assembly.

Update the Coordinator client library, adding partial datagram assembly
and changing the API to be a bit better:
- Parameters are now specified individually via vararg instead of by
  chaining them together with a builder-type struct.
- State requests will always have their state and descriptor values
  filled in, instead of being pointers.
- Tail requests now accept their own set of parameters.

Update Milo's LogDog code to use the Coordinator client library and the
datagram assembly option.

Update `logdog_cat` to use the updated API.

BUG=chromium:647336
TEST=local

Committed: https://github.com/luci/luci-go/commit/aaa142274de3328ee8d2476468e59d0239a8bcf7

[dnj, 2016-09-15 18:04:45]

dnj@chromium.org changed reviewers:
+ hinoka@chromium.org, martiniss@chromium.org

[dnj, 2016-09-15 18:04:46]

PTAL. I've already applied this to Milo.

martiniss@, if you are still using LogDog datagrams, you should use
Tail/Complete after this lands.

[dnj, 2016-09-15 18:13:14]

Description was changed from

==========
Update Coordinator client, add datagram assembly.

Update the Coordinator client library, adding partial datagram assembly
and changing the API to be a bit better:
- Parameters are now specified individually via vararg instead of by
  chaining them together with a builder-type struct.
- State requests will always have their state and descriptor values
  filled in, instead of being pointers.
- Tail requests now accept their own set of parameters.

Update Milo's LogDog code to use the Coordinator client library and the
datagram assembly option.

Update `logdog_cat` to use the updated API.

BUG=None
TEST=local
==========

to

==========
Update Coordinator client, add datagram assembly.

Update the Coordinator client library, adding partial datagram assembly
and changing the API to be a bit better:
- Parameters are now specified individually via vararg instead of by
  chaining them together with a builder-type struct.
- State requests will always have their state and descriptor values
  filled in, instead of being pointers.
- Tail requests now accept their own set of parameters.

Update Milo's LogDog code to use the Coordinator client library and the
datagram assembly option.

Update `logdog_cat` to use the updated API.

BUG=chromium:647336
TEST=local
==========

[martiniss, 2016-09-15 20:37:11]

On 2016/09/15 at 18:04:46, dnj wrote:
> PTAL. I've already applied this to Milo.
> 
> martiniss@, if you are still using LogDog datagrams, you should use
Tail/Complete after this lands.

I'm not planning on it; I think I'll use the google storage bucket directly. But
thanks! :) I'll review this.

[martiniss, 2016-09-22 03:40:39]

lgtm

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/cmd/logdo...
File logdog/client/cmd/logdog_cat/subcommandQuery.go (left):

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/cmd/logdo...
logdog/client/cmd/logdog_cat/subcommandQuery.go:225: if s.State != nil {
Why did this check go away?

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
File logdog/client/coordinator/stream_test.go (right):

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
logdog/client/coordinator/stream_test.go:556: So(err, ShouldErrLike, "failed to
get intermediate logs")
test for test error in the err?

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
logdog/client/coordinator/stream_test.go:630: Convey(`If the previous datagram
is partial, will return it reassembled.`, func() {
nit: move this above the other test?

https://codereview.chromium.org/2341113002/diff/20001/milo/appengine/logdog/h...
File milo/appengine/logdog/http.go (right):

https://codereview.chromium.org/2341113002/diff/20001/milo/appengine/logdog/h...
milo/appengine/logdog/http.go:64: as.logDogClient =
coordinator.NewClient(&prpc.Client{
why was this moved?

[dnj, 2016-09-22 16:00:05]

Thanks for reviewing!

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/cmd/logdo...
File logdog/client/cmd/logdog_cat/subcommandQuery.go (left):

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/cmd/logdo...
logdog/client/cmd/logdog_cat/subcommandQuery.go:225: if s.State != nil {
On 2016/09/22 03:40:39, martiniss wrote:
> Why did this check go away?

The State is no longer a pointer.

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
File logdog/client/coordinator/stream_test.go (right):

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
logdog/client/coordinator/stream_test.go:556: So(err, ShouldErrLike, "failed to
get intermediate logs")
On 2016/09/22 03:40:39, martiniss wrote:
> test for test error in the err?

Done. I'll have to make this function return a gRPC error so it's not stripped
and substituted for Internal.

https://codereview.chromium.org/2341113002/diff/20001/logdog/client/coordinat...
logdog/client/coordinator/stream_test.go:630: Convey(`If the previous datagram
is partial, will return it reassembled.`, func() {
On 2016/09/22 03:40:39, martiniss wrote:
> nit: move this above the other test?

Done.

https://codereview.chromium.org/2341113002/diff/20001/milo/appengine/logdog/h...
File milo/appengine/logdog/http.go (right):

https://codereview.chromium.org/2341113002/diff/20001/milo/appengine/logdog/h...
milo/appengine/logdog/http.go:64: as.logDogClient =
coordinator.NewClient(&prpc.Client{
On 2016/09/22 03:40:39, martiniss wrote:
> why was this moved?

Previously, "logDogClient" was an http.Client. Now it's a coordinator.Client.
They are initialized differently.

[dnj, 2016-09-22 16:00:29]

The CQ bit was checked by dnj@chromium.org

[dnj, 2016-09-22 16:00:29]

The patchset sent to the CQ was uploaded after l-g-t-m from
martiniss@chromium.org
Link to the patchset: https://codereview.chromium.org/2341113002/#ps40001
(title: "Comments.")

[commit-bot: I haz the power, 2016-09-22 16:00:40]

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, 2016-09-22 16:09:08]

Description was changed from

==========
Update Coordinator client, add datagram assembly.

Update the Coordinator client library, adding partial datagram assembly
and changing the API to be a bit better:
- Parameters are now specified individually via vararg instead of by
  chaining them together with a builder-type struct.
- State requests will always have their state and descriptor values
  filled in, instead of being pointers.
- Tail requests now accept their own set of parameters.

Update Milo's LogDog code to use the Coordinator client library and the
datagram assembly option.

Update `logdog_cat` to use the updated API.

BUG=chromium:647336
TEST=local
==========

to

==========
Update Coordinator client, add datagram assembly.

Update the Coordinator client library, adding partial datagram assembly
and changing the API to be a bit better:
- Parameters are now specified individually via vararg instead of by
  chaining them together with a builder-type struct.
- State requests will always have their state and descriptor values
  filled in, instead of being pointers.
- Tail requests now accept their own set of parameters.

Update Milo's LogDog code to use the Coordinator client library and the
datagram assembly option.

Update `logdog_cat` to use the updated API.

BUG=chromium:647336
TEST=local

Committed:
https://github.com/luci/luci-go/commit/aaa142274de3328ee8d2476468e59d0239a8bcf7
==========

[commit-bot: I haz the power, 2016-09-22 16:09:09]

Committed patchset #3 (id:40001) as
https://github.com/luci/luci-go/commit/aaa142274de3328ee8d2476468e59d0239a8bcf7