vpython: Add environment spec package.

vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
- Inline, in an entry point script.

BUG=chromium:691818
TEST=unit

Review-Url: https://codereview.chromium.org/2705623003
Committed: https://github.com/luci/luci-go/commit/fa008f62168a77f43978a9da9dc6aa22de82bbc5

[dnj, 2017-02-17 23:13:48]

Description was changed from

==========
Updated patchset dependency

vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
  - Inline, in an entry point script.

BUG=chromium:691818
TEST=unit
==========

to

==========
vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
  - Inline, in an entry point script.

BUG=chromium:691818
TEST=unit
==========

[dnj, 2017-02-17 23:17:29]

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

[dnj, 2017-02-17 23:17:29]

PTAL! This is part of a larger "vpython" CL set for the tool. More information
can be found in the bug, or in the linked design doc:
https://docs.google.com/document/d/1GKN7rtW6-006RbG_Ryh6vr4TpUxSxJlPSCKFLq2nO...

Total CL set is:
https://codereview.chromium.org/2703463006/ (README, protobufs)
https://codereview.chromium.org/2703793003/ (filesystem)
https://codereview.chromium.org/2700273002/ (wheel)
https://codereview.chromium.org/2705623003/ (environment spec)
https://codereview.chromium.org/2701073002/ (Python interpreter management)
https://codereview.chromium.org/2699063004/ (main VirtualEnv package)
https://codereview.chromium.org/2699223002/ (CIPD support)
https://codereview.chromium.org/2702873002/ (package entry point)
https://codereview.chromium.org/2705593003/ (main application)
https://chromium-review.googlesource.com/c/444040/ (Infra entry point)

[iannucci, 2017-02-21 08:34:44]

Description was changed from

==========
vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
  - Inline, in an entry point script.

BUG=chromium:691818
TEST=unit
==========

to

==========
vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
- Inline, in an entry point script.

BUG=chromium:691818
TEST=unit
==========

[iannucci, 2017-02-21 09:09:55]

lgtm

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go
File vpython/spec/load.go (right):

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcode29
vpython/spec/load.go:29: // Load loads an environment specification file text
protobuf from the supplied
let's be careful not to overload 'environment' here, since we also use
environment variables. Maybe just 'vpython spec file'?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcode31
vpython/spec/load.go:31: func Load(path string) (*env.Spec, error) {
I don't suppose we can s/env/vpython?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:183: // Otherwise, try and find the ES file associated with
this script.
otherwise?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:193: // If it's a directory, scan for an ".es" file until
we don't have a
.es file?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:280: prefix = ""
should this just be an error?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:290: }
what happens in the else case? doesn't matter?

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go
File vpython/spec/spec.go (right):

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go#newcode21
vpython/spec/spec.go:21: // with identical meaning will have the same identical
representation.
"same identical"

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go#newcode53
vpython/spec/spec.go:53: func (s envSpecPackageSlice) Less(i, j int) bool {
try sortby! https://github.com/luci/luci-go/tree/master/common/data/sortby

return sortby.Chain{
  func(i, j int) bool { return s[i].Path < s[j].Path },
  func(i, j int) bool { return s[i].Version < s[j].Version },
}.Use(i, j)

[dnj, 2017-02-22 07:37:19]

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go
File vpython/spec/load.go (right):

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcode29
vpython/spec/load.go:29: // Load loads an environment specification file text
protobuf from the supplied
On 2017/02/21 09:09:55, iannucci wrote:
> let's be careful not to overload 'environment' here, since we also use
> environment variables. Maybe just 'vpython spec file'?

Done.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcode31
vpython/spec/load.go:31: func Load(path string) (*env.Spec, error) {
On 2017/02/21 09:09:55, iannucci wrote:
> I don't suppose we can s/env/vpython?

hrm sure, done.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:183: // Otherwise, try and find the ES file associated with
this script.
On 2017/02/21 09:09:54, iannucci wrote:
> otherwise?

Done.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:193: // If it's a directory, scan for an ".es" file until
we don't have a
On 2017/02/21 09:09:54, iannucci wrote:
> .es file?

Done.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:280: prefix = ""
On 2017/02/21 09:09:54, iannucci wrote:
> should this just be an error?

I don't think so. Let's be a little flexible for now.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/load.go#newcod...
vpython/spec/load.go:290: }
On 2017/02/21 09:09:54, iannucci wrote:
> what happens in the else case? doesn't matter?

Yeah, if there is no shorter prefix to trim, we leave the line as-is.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go
File vpython/spec/spec.go (right):

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go#newcode21
vpython/spec/spec.go:21: // with identical meaning will have the same identical
representation.
On 2017/02/21 09:09:55, iannucci wrote:
> "same identical"

Done.

https://codereview.chromium.org/2705623003/diff/1/vpython/spec/spec.go#newcode53
vpython/spec/spec.go:53: func (s envSpecPackageSlice) Less(i, j int) bool {
On 2017/02/21 09:09:55, iannucci wrote:
> try sortby! https://github.com/luci/luci-go/tree/master/common/data/sortby
> 
> return sortby.Chain{
>   func(i, j int) bool { return s[i].Path < s[j].Path },
>   func(i, j int) bool { return s[i].Version < s[j].Version },
> }.Use(i, j)

Oh cool.

[dnj, 2017-02-22 07:38:32]

The CQ bit was checked by dnj@chromium.org

[dnj, 2017-02-22 07:38:32]

The patchset sent to the CQ was uploaded after l-g-t-m from
iannucci@chromium.org
Link to the patchset: https://codereview.chromium.org/2705623003/#ps40001
(title: "env to vpython, comments")

[commit-bot: I haz the power, 2017-02-22 07:38:37]

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, 2017-02-22 07:43:52]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1487749112542000,
"parent_rev": "d225f829fb168a0fe57b96206a6210b4f728c9e9", "commit_rev":
"fa008f62168a77f43978a9da9dc6aa22de82bbc5"}

[commit-bot: I haz the power, 2017-02-22 07:43:56]

Description was changed from

==========
vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
- Inline, in an entry point script.

BUG=chromium:691818
TEST=unit
==========

to

==========
vpython: Add environment spec package.

This package is used by "vpython" to locate, load, and manipulate the
environment specification.

The specification can be loaded in numerous ways (detailed in README):
- From an arbitrary external file on the disk.
- From a file on disk alongside a script entry point (test.py /
  test.py.vpython).
- Inline, in an entry point script.

BUG=chromium:691818
TEST=unit

Review-Url: https://codereview.chromium.org/2705623003
Committed:
https://github.com/luci/luci-go/commit/fa008f62168a77f43978a9da9dc6aa22de82bbc5
==========

[commit-bot: I haz the power, 2017-02-22 07:43:57]

Committed patchset #3 (id:40001) as
https://github.com/luci/luci-go/commit/fa008f62168a77f43978a9da9dc6aa22de82bbc5