Remove ce-ee merge documentation

doc/development/README.md

@@ -19,7 +19,6 @@ description: 'Learn how to contribute to GitLab.'
 - [Code review guidelines](code_review.md) for reviewing code and having code reviewed
 - [Database review guidelines](database_review.md) for reviewing database-related changes and complex SQL queries
 - [Pipelines for the GitLab project](pipelines.md)
-- [Automatic CE->EE merge](automatic_ce_ee_merge.md)
 - [Guidelines for implementing Enterprise Edition features](ee_features.md)
 - [Security process for developers](https://gitlab.com/gitlab-org/release/docs/blob/master/general/security/developer.md#security-releases-critical-non-critical-as-a-developer)
 - [Requesting access to Chatops on GitLab.com](chatops_on_gitlabcom.md#requesting-access) (for GitLabbers)

doc/development/automatic_ce_ee_merge.md

-# Automatic CE->EE merge
-
-Commits pushed to CE `master` are automatically merged into EE `master` roughly
-every 5 minutes. Changes are merged using the `recursive=ours` merge strategy in
-the context of EE. This means that any merge conflicts are resolved by taking
-the EE changes and discarding the CE changes. This removes the need for
-resolving conflicts or reverting changes, at the cost of **absolutely
-requiring** EE merge requests to be created whenever a CE merge request causes
-merge conflicts.  Failing to do so can result in changes not making their way
-into EE.
-
-## Always create an EE merge request if there are conflicts
-
-In CI there is a job called `ee_compat_check`, which checks if a CE MR causes
-merge conflicts with EE. If this job reports conflicts, you **must** create an
-EE merge request. If you are an external contributor you can ask the reviewer to
-do this for you.
-
-## Always merge EE merge requests before their CE counterparts
-
-**In order to avoid conflicts in the CE->EE merge, you should always merge the
-EE version of your CE merge request first, if present.**
-
-Failing to do so will lead to CE changes being discarded when merging into EE,
-if they cause merge conflicts.
-
-## Avoiding CE->EE merge conflicts beforehand
-
-To avoid the conflicts beforehand, check out the
-[Guidelines for implementing Enterprise Edition features](ee_features.md).
-
-In any case, the CI `ee_compat_check` job will tell you if you need to open an
-EE version of your CE merge request.
-
-### Conflicts detection in CE merge requests
-
-For each commit (except on `master`), the `ee_compat_check` CI job tries to
-detect if the current branch's changes will conflict during the CE->EE merge.
-
-The job reports what files are conflicting and how to set up a merge request
-against EE.
-
-#### How the job works
-
-1. Generates the diff between your branch and current CE `master`
-1. Tries to apply it to current EE `master`
-1. If it applies cleanly, the job succeeds, otherwise...
-1. Detects a branch with the `ee-` prefix or `-ee` suffix in EE
-1. If it exists, generate the diff between this branch and current EE `master`
-1. Tries to apply it to current EE `master`
-1. If it applies cleanly, the job succeeds
-
-In the case where the job fails, it means you should create an `ee-<ce_branch>`
-or `<ce_branch>-ee` branch, push it to EE and open a merge request against EE
-`master`.
-At this point if you retry the failing job in your CE merge request, it should
-now pass.
-
-Notes:
-
-- This task is not a silver-bullet, its current goal is to bring awareness to
-  developers that their work needs to be ported to EE.
-- Community contributors shouldn't be required to submit merge requests against
-  EE, but reviewers should take actions by either creating such EE merge request
-  or asking a GitLab developer to do it **before the merge request is merged**.
-- If you branch is too far behind `master`, the job will fail. In that case you
-  should rebase your branch upon latest `master`.
-- Code reviews for merge requests often consist of multiple iterations of
-  feedback and fixes. There is no need to update your EE MR after each
-  iteration. Instead, create an EE MR as soon as you see the
-  `ee_compat_check` job failing. After you receive the final approval
-  from a Maintainer (but **before the CE MR is merged**) update the EE MR.
-  This helps to identify significant conflicts sooner, but also reduces the
-  number of times you have to resolve conflicts.
-- Please remember to
-  [always have your EE merge request merged before the CE version](#always-merge-ee-merge-requests-before-their-ce-counterparts).
-- You can use [`git rerere`](https://git-scm.com/docs/git-rerere)
-  to avoid resolving the same conflicts multiple times.
-
-### Cherry-picking from CE to EE
-
-For avoiding merge conflicts, we use a method of creating equivalent branches
-for CE and EE. If the `ee-compat-check` job fails, this process is required.
-
-This method only requires that you have cloned both CE and EE into your computer.
-If you don't have them yet, please go ahead and clone them:
-
-- Clone CE repo: `git clone git@gitlab.com:gitlab-org/gitlab-foss.git`
-- Clone EE repo: `git clone git@gitlab.com:gitlab-org/gitlab.git`
-
-And the only additional setup we need is to add CE as remote of EE and vice-versa:
-
-- Open two terminal windows, one in CE, and another one in EE:
-  - In EE: `git remote add ce git@gitlab.com:gitlab-org/gitlab-foss.git`
-  - In CE: `git remote add ee git@gitlab.com:gitlab-org/gitlab.git`
-
-That's all setup we need, so that we can cherry-pick a commit from CE to EE, and
-from EE to CE.
-
-Now, every time you create an MR for CE and EE:
-
-1. Open two terminal windows, one in CE, and another one in EE
-1. In the CE terminal:
-   1. Create the CE branch, e.g., `branch-example`
-   1. Make your changes and push a commit (commit A)
-   1. Create the CE merge request in GitLab
-1. In the EE terminal:
-   1. Create the EE-equivalent branch ending with `-ee`, e.g.,
-      `git checkout -b branch-example-ee`
-   1. Fetch the CE branch: `git fetch ce branch-example`
-   1. Cherry-pick the commit A: `git cherry-pick commit-A-SHA`
-   1. If Git prompts you to fix the conflicts, do a `git status`
-      to check which files contain conflicts, fix them, save the files
-   1. Add the changes with `git add .` but **DO NOT commit** them
-   1. Continue cherry-picking: `git cherry-pick --continue`
-   1. Push to EE: `git push origin branch-example-ee`
-1. Create the EE-equivalent MR and link to the CE MR from the
-   description `Ports [CE-MR-LINK] to EE`
-1. Once all the jobs are passing in both CE and EE, you've addressed the
-   feedback from your own team, and got them approved, the merge requests can be merged.
-1. When both MRs are ready, the EE merge request will be merged first, and the
-   CE-equivalent will be merged next.
-
-**Important notes:**
-
-- The commit SHA can be easily found from the GitLab UI. From a merge request,
-  open the tab **Commits** and click the copy icon to copy the commit SHA.
-- To cherry-pick a **commit range**, such as (A > B > C > D) use:
-
-  ```shell
-  git cherry-pick "oldest-commit-SHA^..newest-commit-SHA"
-  ```
-
-  For example, suppose the commit A is the oldest, and its SHA is `4f5e4018c09ed797fdf446b3752f82e46f5af502`,
-  and the commit D is the newest, and its SHA is `80e1c9e56783bd57bd7129828ec20b252ebc0538`.
-  The cherry-pick command will be:
-
-  ```shell
-  git cherry-pick "4f5e4018c09ed797fdf446b3752f82e46f5af502^..80e1c9e56783bd57bd7129828ec20b252ebc0538"
-  ```
-
-- To cherry-pick a **merge commit**, use the flag `-m 1`. For example, suppose that the
-  merge commit SHA is `138f5e2f20289bb376caffa0303adb0cac859ce1`:
-
-  ```shell
-  git cherry-pick -m 1 138f5e2f20289bb376caffa0303adb0cac859ce1
-  ```
-
-- To cherry-pick multiple commits, such as B and D in a range (A > B > C > D), use:
-
-  ```shell
-  git cherry-pick commit-B-SHA commit-D-SHA
-  ```
-
-  For example, suppose commit B SHA = `4f5e4018c09ed797fdf446b3752f82e46f5af502`,
-  and the commit D SHA = `80e1c9e56783bd57bd7129828ec20b252ebc0538`.
-  The cherry-pick command will be:
-
-  ```shell
-  git cherry-pick 4f5e4018c09ed797fdf446b3752f82e46f5af502 80e1c9e56783bd57bd7129828ec20b252ebc0538
-  ```
-
-  This case is particularly useful when you have a merge commit in a sequence of
-  commits and you want to cherry-pick all but the merge commit.
-
-- If you push more commits to the CE branch, you can safely repeat the procedure
-  to cherry-pick them to the EE-equivalent branch. You can do that as many times as
-  necessary, using the same CE and EE branches.
-- If you submitted the merge request to the CE repo and the `ee-compat-check` job passed,
-  you are not required to submit the EE-equivalent MR, but it's still recommended. If the
-  job failed, you are required to submit the EE MR so that you can fix the conflicts in EE
-  before merging your changes into CE.
-
-## How we run the Automatic CE->EE merge at GitLab
-
-At GitLab, we use the [Merge Train](https://gitlab.com/gitlab-org/merge-train)
-project to keep our [GitLab EE](https://gitlab.com/gitlab-org/gitlab)
-repository updated with commits from
-[GitLab CE](https://gitlab.com/gitlab-org/gitlab-foss).
-
-We have a mirror of the [Merge Train](https://gitlab.com/gitlab-org/merge-train)
-project [configured](https://ops.gitlab.net/gitlab-org/merge-train) to run an
-automatic CE->EE merge job every twenty minutes as a scheduled CI job.  The
-[configured](https://ops.gitlab.net/gitlab-org/merge-train) Merge Train project
-is only accessible to authorized GitLab staff.
-
-## FAQ
-
-### How does automatic merging work?
-
-The automatic merging is performed using a project called [Merge
-Train](https://gitlab.com/gitlab-org/merge-train/). This project will clone CE
-and EE master, and merge CE master into EE master using `git merge
---strategy=recursive --strategy-option=ours`. This process runs multiple times
-per hour.
-
-For more information on the exact implementation you can refer to the source
-code.
-
-### Why merge automatically?
-
-As we work towards continuous deployments and a single repository for both CE
-and EE, we need to first make sure that all CE changes make their way into EE as
-fast as possible. Past experiences and data have shown that periodic CE to EE
-merge requests do not scale, and often take a very long time to complete. For
-example, [in this
-comment](https://gitlab.com/gitlab-org/release/framework/issues/49#note_114614619)
-we determined that the average time to close an upstream merge request is around
-5 hours, with peaks up to several days. Periodic merge requests are also
-frustrating to work with, because they often include many changes unrelated to
-your own changes.
-
-To resolve these problems, we now merge changes using the `ours` strategy to
-automatically resolve merge conflicts. This removes the need for resolving
-conflicts in a periodic merge request, and allows us to merge changes from CE
-into EE much faster.
-
-### My CE merge request caused conflicts after it was merged. What do I do?
-
-If you notice this, you should set up an EE merge request that resolves these
-conflicts as **soon as possible**. Failing to do so can lead to your changes not
-being available in EE, which may break tests. This in turn would prevent us from
-being able to deploy.
-
-### Won't this setup be risky?
-
-No, not if there is an EE merge request for every CE merge request that causes
-conflicts _and_ that EE merge request is merged first. In the past we may have
-been a bit more relaxed when it comes to enforcing EE merge requests, but to
-enable automatic merging we have to start requiring such merge requests even for
-the smallest conflicts.
-
-### Some files I work with often conflict, how can I best deal with this?
-
-If you find you keep running into merge conflicts, consider refactoring the file
-so that the EE specific changes are not intertwined with CE code. For Ruby code
-you can do this by moving the EE code to a separate module, which can then be
-injected into the appropriate classes or modules. See [Guidelines for
-implementing Enterprise Edition features](ee_features.md) for more information.
-
----
-
-[Return to Development documentation](README.md)

doc/workflow/gitlab_flow.md

@@ -168,7 +168,6 @@ This branch is the place for any work related to this change.
 
 NOTE: **Note:**
 The name of a branch might be dictated by organizational standards.
-For example, in GitLab, any branches in GitLab EE that are equivalent to branches in GitLab CE [must end in `-ee`](../development/automatic_ce_ee_merge.md#cherry-picking-from-ce-to-ee).
 
 When you are done or want to discuss the code, open a merge request.
 A merge request is an online place to discuss the change and review the code.