Prior to this MR there were two GitHub related importers:
* Github::Import: the main importer used for GitHub projects
* Gitlab::GithubImport: importer that's somewhat confusingly used for
importing Gitea projects (apparently they have a compatible API)
This MR renames the Gitea importer to Gitlab::LegacyGithubImport and
introduces a new GitHub importer in the Gitlab::GithubImport namespace.
This new GitHub importer uses Sidekiq for importing multiple resources
in parallel, though it also has the ability to import data sequentially
should this be necessary.
The new code is spread across the following directories:
* lib/gitlab/github_import: this directory contains most of the importer
code such as the classes used for importing resources.
* app/workers/gitlab/github_import: this directory contains the Sidekiq
workers, most of which simply use the code from the directory above.
* app/workers/concerns/gitlab/github_import: this directory provides a
few modules that are included in every GitHub importer worker.
== Stages
The import work is divided into separate stages, with each stage
importing a specific set of data. Stages will schedule the work that
needs to be performed, followed by scheduling a job for the
"AdvanceStageWorker" worker. This worker will periodically check if all
work is completed and schedule the next stage if this is the case. If
work is not yet completed this worker will reschedule itself.
Using this approach we don't have to block threads by calling `sleep()`,
as doing so for large projects could block the thread from doing any
work for many hours.
== Retrying Work
Workers will reschedule themselves whenever necessary. For example,
hitting the GitHub API's rate limit will result in jobs rescheduling
themselves. These jobs are not processed until the rate limit has been
reset.
== User Lookups
Part of the importing process involves looking up user details in the
GitHub API so we can map them to GitLab users. The old importer used
an in-memory cache, but this obviously doesn't work when the work is
spread across different threads.
The new importer uses a Redis cache and makes sure we only perform
API/database calls if absolutely necessary. Frequently used keys are
refreshed, and lookup misses are also cached; removing the need for
performing API/database calls if we know we don't have the data we're
looking for.
== Performance & Models
The new importer in various places uses raw INSERT statements (as
generated by `Gitlab::Database.bulk_insert`) instead of using Rails
models. This allows us to bypass any validations and callbacks,
drastically reducing the number of SQL queries and Gitaly RPC calls
necessary to import projects.
To ensure the code produces valid data the corresponding tests check if
the produced rows are valid according to the model validation rules.
In GitLab EE, a GitLab instance can be read-only (e.g. when it's a Geo
secondary node). But in GitLab CE it also might be useful to have the
"read-only" idea around. So port it back to GitLab CE.
Also having the principle of read-only in GitLab CE would hopefully
lead to less errors introduced, doing write operations when there
aren't allowed for read-only calls.
Closesgitlab-org/gitlab-ce#37534.
Because of a change in GitLab 9.5.4 to prevent users from assuming control of
a repository already on disk, the import task broke. Imports would fail with
the message, "There is already a repository with that name on disk".
This change skips the validation when the import is done from the
command-line.
Closes#37682
This adds Project#latest_successful_pipeline_for and
Project#latest_successful_pipeline_for_default_branch. The 2nd method
memoizes the result (taking nil values into account) to ensure the
underlying query isn't executed multiple times when viewing a project's
homepage.
See https://gitlab.com/gitlab-org/gitlab-ce/issues/36878#note_40073607
for more information.
The following optimizations were performed:
- Add new association to GroupMember and ProjectMember
This new association will allow us to check if a user is a member of a
Project or Group through a single query instead of two.
- Optimize retrieving of Members when adding multiple Users
There are some redundancies in the validation steps, and that is to
preserve current error messages behavior
Also few specs have to be changed in order to fix madness in validation
logic.
Douwe Maan
Yorick Peterse
Rémy Coutable
Douwe Maan
Markus Koller
Bob Van Landuyt
Kamil Trzciński
Gabriel Mazetto
Matt Coleman
Tim Zallmann
Toon Claes
Shinya Maeda
Alessio Caiazza
Zeger-Jan van de Weg
Sean McGivern
Stan Hu
Valery Sizov
Jacob Vosmaer
Eric Eastwood
Rubén Dávila
Marin Jankovski
Grzegorz Bizon
Lin Jen-Shin