RE: [PATCH 1/2] Documentation about triangular workflow

[ALBERTIN TIMOTHEE p1514771]

Daniel Bensoussan  writes:

>> +TRIANGULAR WORKFLOW
>> +---
>> +
>> +Introduction
>> +
>> +
>> +In some projects, contributors cannot push directly to the project but
>> +have to suggest their commits to the maintainer (e.g. pull requests).
>> +For these projects, it's common to use what's called a *triangular
>> +workflow*:
>> + ...
>> +Motivations
>> +~~~
>> +
>> +* Allows contributors to work with Git even if they don't have
>> +write access to **UPSTREAM**.
>> +
>> +Indeed, in a centralized workflow, a contributor without write access
>> +could write some code but could not send it by itself.  The contributor
>> +was forced to create a mail which shows the difference between the
>> +new and the old code, and then send it to a maintainer to commit
>> +and push it.  This isn't convenient at all, neither for the
>> +contributor, neither for the maintainer. With the triangular
>> +workflow, the contributors have the write access on **PUBLISH**
>> +so they don't have to pass upon maintainer(s).  And only the
>> +maintainer(s) can push from **PUBLISH** to **UPSTREAM**.
>> +This is called a distributed workflow (See "DISTRIBUTED WORKFLOWS"
>> +above).

>I probably should not be judging if these additions to
>gitworkflows.txt is a good idea in the first place without seeing
>any explanation as to why this patch is here, but I think it misses
>the place where "triangular" sits in a larger picture.

There already have been a discussion about this documentation:
https://public-inbox.org/git/e83a9439-54c8-4925-8ee3-6aeedd941...@grenoble-inp.org/
We forgot to add it to the commit message, it will be in the next
commit message.

>The workflow to contrast against to illustrate the motivation is a
>centralized workflow, where everybody pushes their updates to a
>single place.  It does have problems inherent to its structure
>(e.g. "review before integration" is much harder, if possible), and
>also has its merits (e.g. it is simpler to explain and reason
>about).

>If you want to wean a project off of the centralized model, you'd
>need to use the "distributed workflow".  The workflow to review and
>apply mailed patches in public, and the workflow to have the project
>pull from many publish repositories individual contributor has, are
>two that allows the project to go distributed.  These two are
>complementary choices with pros and cons, and it is not like one is
>an improvement of the other.  Projects like the kernel even uses
>hybrid of the two---the patches are reviewed in public at central
>places (i.e. subsystem mailing lists) in an e-mail form and go
>through iterations getting polished, and the polished results are
>collected by (sub)maintainers and sent upwards, either as a request
>to pull from publish repositories maintained by (sub)maintainers, or
>relayed again in e-mail form (the last mile being e-mail primarily
>serves as a transport vehicle for changes proven to be good, not as
>material to be further reviewed).

>The reason why projects make these choices is because there are pros
>and cons.  A large collection of changes is far easier to integrate
>with one command (i.e. "git pull") and with a need to resolve merge
>conflicts just once, than applying many small changes as e-mailed
>patches, having to resolve many conflicts along the way.  In order
>to ensure quality of the individual changes, however, the changes
>need to be reviewed and polished, and the reality of the life is
>that there are far fewer people who are qualified to adequately
>review and help polishing the changes than those who make changes.
>Asking reviewers to go to different repositories (whose number
>scales with the number of contributors) and leave comments in the
>webforms is much less efficient and more costly for the project
>overall, than asking them to subscribe to relevant mailing lists
>(whose number scales only with the number of areas of interest) and
>conduct reviews there.  Other factors like "offline access" also
>count when considering the two models as "choices".

>As long as the document uses phrases like "forced to", "isn't
>convenient at all", etc., it is clear that it starts from a wrong
>premise, "one is an improvement over the other".

We will take this into account.
We didn't know there were hybrid workflows.

Thank you for your time

Timothée Albertin

RE: [PATCH 1/2] Documentation about triangular workflow

[ALBERTIN TIMOTHEE p1514771]

>On 17 November 2017 at 17:07, Daniel Bensoussan
> wrote:
>> +- If the maintainer accepts the changes, he merges them into the
>> +  **UPSTREAM** repository.

>Personally, I would prefer "they" and "their" over "he" and "his". I'm
>not sure how universal this preference is, but see also 715a51bcaf (am:
>counteract gender bias, 2016-07-08). I realize that "he" is already used
>in this document...

This could be a good thing in order to be neutral.  We can change this in
the whole file.

>> + ... The contributor
>> +was forced to create a mail which shows the difference between the
>> +new and the old code, and then send it to a maintainer to commit
>> +and push it.  This isn't convenient at all, neither for the
>> +contributor, neither for the maintainer.

>"neither ... nor". That said, I find the tone of this paragraph a bit
>value-loaded ("forced ... isn't convenient at all"). It does sort of
>contradict or at least compare interestingly with how git.git itself is
>maintained. ;-) Maybe this could be framed in a more neutral way?

Junio C Hamano told us the same thing about the motivation
section, we'll change it the next patch.

>> +The goal of the triangular workflow is also that the rest of the
>> +community or the company can review the code before it's in production.
>> +Everyone can read on **PUBLISH** so everyone can review code
>> +before the maintainer(s) merge it to **UPSTREAM**.  It also means

>I think you can drop the "(s)". Your example workflow could have a
>single maintainer. In a multi-maintainer workflow, the workflow would
>still be the same. So no need to cover all bases by sprinkling "(s)" on
>the text. (IMHO.)

We'll fix that.


Thank you for your review.

Timothée Albertin

Re: [PATCH 1/2] Documentation about triangular workflow

[Junio C Hamano]

Daniel Bensoussan  writes:

> +TRIANGULAR WORKFLOW
> +---
> +
> +Introduction
> +
> +
> +In some projects, contributors cannot push directly to the project but
> +have to suggest their commits to the maintainer (e.g. pull requests).
> +For these projects, it's common to use what's called a *triangular
> +workflow*:
> + ...
> +Motivations
> +~~~
> +
> +* Allows contributors to work with Git even if they don't have
> +write access to **UPSTREAM**.
> +
> +Indeed, in a centralized workflow, a contributor without write access
> +could write some code but could not send it by itself.  The contributor
> +was forced to create a mail which shows the difference between the
> +new and the old code, and then send it to a maintainer to commit
> +and push it.  This isn't convenient at all, neither for the
> +contributor, neither for the maintainer. With the triangular
> +workflow, the contributors have the write access on **PUBLISH**
> +so they don't have to pass upon maintainer(s).  And only the
> +maintainer(s) can push from **PUBLISH** to **UPSTREAM**.
> +This is called a distributed workflow (See "DISTRIBUTED WORKFLOWS"
> +above).

I probably should not be judging if these additions to
gitworkflows.txt is a good idea in the first place without seeing
any explanation as to why this patch is here, but I think it misses
the place where "triangular" sits in a larger picture.

The workflow to contrast against to illustrate the motivation is a
centralized workflow, where everybody pushes their updates to a
single place.  It does have problems inherent to its structure
(e.g. "review before integration" is much harder, if possible), and
also has its merits (e.g. it is simpler to explain and reason
about).

If you want to wean a project off of the centralized model, you'd
need to use the "distributed workflow".  The workflow to review and
apply mailed patches in public, and the workflow to have the project
pull from many publish repositories individual contributor has, are
two that allows the project to go distributed.  These two are
complementary choices with pros and cons, and it is not like one is
an improvement of the other.  Projects like the kernel even uses
hybrid of the two---the patches are reviewed in public at central
places (i.e. subsystem mailing lists) in an e-mail form and go
through iterations getting polished, and the polished results are
collected by (sub)maintainers and sent upwards, either as a request
to pull from publish repositories maintained by (sub)maintainers, or
relayed again in e-mail form (the last mile being e-mail primarily
serves as a transport vehicle for changes proven to be good, not as
material to be further reviewed).

The reason why projects make these choices is because there are pros
and cons.  A large collection of changes is far easier to integrate
with one command (i.e. "git pull") and with a need to resolve merge
conflicts just once, than applying many small changes as e-mailed
patches, having to resolve many conflicts along the way.  In order
to ensure quality of the individual changes, however, the changes
need to be reviewed and polished, and the reality of the life is
that there are far fewer people who are qualified to adequately
review and help polishing the changes than those who make changes.
Asking reviewers to go to different repositories (whose number
scales with the number of contributors) and leave comments in the
webforms is much less efficient and more costly for the project
overall, than asking them to subscribe to relevant mailing lists
(whose number scales only with the number of areas of interest) and
conduct reviews there.  Other factors like "offline access" also
count when considering the two models as "choices".

As long as the document uses phrases like "forced to", "isn't
convenient at all", etc., it is clear that it starts from a wrong
premise, "one is an improvement over the other".

Re: [PATCH 1/2] Documentation about triangular workflow

[Martin Ågren]

On 17 November 2017 at 17:07, Daniel Bensoussan
 wrote:
> +- If the maintainer accepts the changes, he merges them into the
> +  **UPSTREAM** repository.

Personally, I would prefer "they" and "their" over "he" and "his". I'm
not sure how universal this preference is, but see also 715a51bcaf (am:
counteract gender bias, 2016-07-08). I realize that "he" is already used
in this document...

> + ... The contributor
> +was forced to create a mail which shows the difference between the
> +new and the old code, and then send it to a maintainer to commit
> +and push it.  This isn't convenient at all, neither for the
> +contributor, neither for the maintainer.

"neither ... nor". That said, I find the tone of this paragraph a bit
value-loaded ("forced ... isn't convenient at all"). It does sort of
contradict or at least compare interestingly with how git.git itself is
maintained. ;-) Maybe this could be framed in a more neutral way?

> +The goal of the triangular workflow is also that the rest of the
> +community or the company can review the code before it's in production.
> +Everyone can read on **PUBLISH** so everyone can review code
> +before the maintainer(s) merge it to **UPSTREAM**.  It also means

I think you can drop the "(s)". Your example workflow could have a
single maintainer. In a multi-maintainer workflow, the workflow would
still be the same. So no need to cover all bases by sprinkling "(s)" on
the text. (IMHO.)

I'll follow up with some comments on patch 2/2...

Martin

Re: [PATCH 1/2] Documentation about triangular workflow

[Stefan Beller]

Thanks for contributing to Git and making the documentation better!

On Fri, Nov 17, 2017 at 8:07 AM, Daniel Bensoussan
 wrote:
> From: ALBERTIN TIMOTHEE 11514771 

This is a place where you can describe why this change is awesome (and
hence the project is interested in including it.)

The Git projects requires your Sign-off (and by the differing author
and you as a sender, both of you)
See Documentation/SubmittingPatches or
https://developercertificate.org/ and if you can agree
to that add a line "Signed-off-by: name " to the commit message
of the text.

>
> diff --git a/Documentation/gitworkflows.txt b/Documentation/gitworkflows.txt
> index 02569d061..3f1ddba82 100644
> --- a/Documentation/gitworkflows.txt
> +++ b/Documentation/gitworkflows.txt
> @@ -464,6 +464,221 @@ in patches to figure out the merge base.  See 
> linkgit:git-am[1] for
>  other options.
>
>
> +TRIANGULAR WORKFLOW
> +---
> +
> +Introduction
> +
> +
> +In some projects, contributors cannot push directly to the project but
> +have to suggest their commits to the maintainer (e.g. pull requests).
> +For these projects, it's common to use what's called a *triangular
> +workflow*:
> +
> +- The project maintainer publishes a repository, called **UPSTREAM** in
> +this document, which is a read-only for contributors. They can clone and
> +fetch from this repository.
> +- Contributors publish their modifications by pushing to a repository,
> +called **PUBLISH** in this document, and request a merge.
> +- Opening a pull request
> +- If the maintainer accepts the changes, he merges them into the
> +  **UPSTREAM** repository.
> +
> +This workflow is commonly used on different platforms like BitBucket,
> +GitHub or GitLab which provide a dedicated mechanism for requesting merges.
> +
> +
> +--   -
> +| UPSTREAM   |  maintainer   | PUBLISH   |
> +|  git/git   |- - - - - - - -|  me/remote|
> +--  <-   -
> +  \ /
> +   \   /
> +fetch | \ / ^ push
> +  v  \   /  |
> +  \ /
> +   -
> +   |   LOCAL   |
> +   -
> +

git/git as the upstream is a notable example which doesn't
use this triangular workflow, as most patches are accepted
via email, such that the PUBLISH remote may not exist when
contributing to git/git. (Though https://submitgit.herokuapp.com/
tries to emulate the triangular workflow for contributors)


> +This is just a side-effect of the "review before merge" mentionned
> +above but this is still a good point.

mentioned (typo)