Close #13539.

Co-authored by: @lunny @appleboy @fuxiaohei and others.

Related projects:
- https://gitea.com/gitea/actions-proto-def
- https://gitea.com/gitea/actions-proto-go
- https://gitea.com/gitea/act
- https://gitea.com/gitea/act_runner

### Summary

The target of this PR is to bring a basic implementation of "Actions",
an internal CI/CD system of Gitea. That means even though it has been
merged, the state of the feature is **EXPERIMENTAL**, and please note
that:

- It is disabled by default;
- It shouldn't be used in a production environment currently;
- It shouldn't be used in a public Gitea instance currently;
- Breaking changes may be made before it's stable.

**Please comment on #13539 if you have any different product design
ideas**, all decisions reached there will be adopted here. But in this
PR, we don't talk about **naming, feature-creep or alternatives**.

### ⚠️ Breaking

`gitea-actions` will become a reserved user name. If a user with the
name already exists in the database, it is recommended to rename it.

### Some important reviews

- What is `DEFAULT_ACTIONS_URL` in `app.ini` for?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1055954954
- Why the api for runners is not under the normal `/api/v1` prefix?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1061173592
- Why DBFS?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1061301178
- Why ignore events triggered by `gitea-actions` bot?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1063254103
- Why there's no permission control for actions?
  - https://github.com/go-gitea/gitea/pull/21937#discussion_r1090229868

### What it looks like

<details>

#### Manage runners

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205870657-c72f590e-2e08-4cd4-be7f-2e0abb299bbf.png">

#### List runs

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205872794-50fde990-2b45-48c1-a178-908e4ec5b627.png">


#### View logs

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205872501-9b7b9000-9542-4991-8f55-18ccdada77c3.png">



</details>

### How to try it

<details>

#### 1. Start Gitea

Clone this branch and [install from
source](https://docs.gitea.io/en-us/install-from-source).

Add additional configurations in `app.ini` to enable Actions:

```ini
[actions]
ENABLED = true
```

Start it.

If all is well, you'll see the management page of runners:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205877365-8e30a780-9b10-4154-b3e8-ee6c3cb35a59.png">


#### 2. Start runner

Clone the [act_runner](https://gitea.com/gitea/act_runner), and follow
the
[README](https://gitea.com/gitea/act_runner/src/branch/main/README.md)
to start it.

If all is well, you'll see a new runner has been added:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205878000-216f5937-e696-470d-b66c-8473987d91c3.png">

#### 3. Enable actions for a repo

Create a new repo or open an existing one, check the `Actions` checkbox
in settings and submit.

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205879705-53e09208-73c0-4b3e-a123-2dcf9aba4b9c.png">
<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205879383-23f3d08f-1a85-41dd-a8b3-54e2ee6453e8.png">

If all is well, you'll see a new tab "Actions":

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205881648-a8072d8c-5803-4d76-b8a8-9b2fb49516c1.png">

#### 4. Upload workflow files

Upload some workflow files to `.gitea/workflows/xxx.yaml`, you can
follow the [quickstart](https://docs.github.com/en/actions/quickstart)
of GitHub Actions. Yes, Gitea Actions is compatible with GitHub Actions
in most cases, you can use the same demo:

```yaml
name: GitHub Actions Demo
run-name: ${{ github.actor }} is testing out GitHub Actions 🚀
on: [push]
jobs:
  Explore-GitHub-Actions:
    runs-on: ubuntu-latest
    steps:
      - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
      - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!"
      - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."
      - name: Check out repository code
        uses: actions/checkout@v3
      - run: echo "💡 The ${{ github.repository }} repository has been cloned to the runner."
      - run: echo "🖥️ The workflow is now ready to test your code on the runner."
      - name: List files in the repository
        run: |
          ls ${{ github.workspace }}
      - run: echo "🍏 This job's status is ${{ job.status }}."
```

If all is well, you'll see a new run in `Actions` tab:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205884473-79a874bc-171b-4aaf-acd5-0241a45c3b53.png">

#### 5. Check the logs of jobs

Click a run and you'll see the logs:

<img width="1792" alt="image"
src="https://user-images.githubusercontent.com/9418365/205884800-994b0374-67f7-48ff-be9a-4c53f3141547.png">

#### 6. Go on

You can try more examples in [the
documents](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions)
of GitHub Actions, then you might find a lot of bugs.

Come on, PRs are welcome.

</details>

See also: [Feature Preview: Gitea
Actions](https://blog.gitea.io/2022/12/feature-preview-gitea-actions/)

---------

Co-authored-by: a101211279 <1012112796@qq.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: Lauris BH <lauris@nix.lv>

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

This PR adds a context parameter to a bunch of methods. Some helper
`xxxCtx()` methods got replaced with the normal name now.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

fix #19349 , #19505

Co-authored-by: delvh <dev.lh@web.de>

Found using
`find . -type f -name '*.go' -print -exec vim {} -c
':%s/fmt\.Errorf(\(.*\)%v\(.*\)err/fmt.Errorf(\1%w\2err/g' -c ':wq' \;`

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

A lot of our code is repeatedly testing if individual errors are
specific types of Not Exist errors. This is repetitative and unnecesary.
`Unwrap() error` provides a common way of labelling an error as a
NotExist error and we can/should use this.

This PR has chosen to use the common `io/fs` errors e.g.
`fs.ErrNotExist` for our errors. This is in some ways not completely
correct as these are not filesystem errors but it seems like a
reasonable thing to do and would allow us to simplify a lot of our code
to `errors.Is(err, fs.ErrNotExist)` instead of
`package.IsErr...NotExist(err)`

I am open to suggestions to use a different base error - perhaps
`models/db.ErrNotExist` if that would be felt to be better.


Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: delvh <dev.lh@web.de>

Found via `codespell -q 3 -S
./options/locale,./options/license,./public/vendor,./web_src/fomantic -L
actived,allways,attachements,ba,befores,commiter,pullrequest,pullrequests,readby,splitted,te,unknwon`

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* Move some files into models' sub packages

* Move functions

* merge main branch

* Fix check

* fix check

* Fix some tests

* Fix lint

* Fix lint

* Revert lint changes

* Fix error comments

* Fix lint

Co-authored-by: 6543 <6543@obermui.de>

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

* Move access and repo permission to models/perm/access

* fix test

* fix git test

* Move functions sequence

* Some improvements per @KN4CK3R and @delvh

* Move issues related code to models/issues

* Move some issues related sub package

* Merge

* Fix test

* Fix test

* Fix test

* Fix test

* Rename some files

* Implement custom regular expression for external issue tracking.

Signed-off-by: Alexander Beyn <malex@fatelectrons.org>

* Fix syntax/style

* Update repo.go

* Set metas['regexp']

* gofmt

* fix some tests

* fix more tests

* refactor frontend

* use LRU cache for regexp

* Update modules/markup/html_internal_test.go

Co-authored-by: Alexander Beyn <malex@fatelectrons.org>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

* Move almost all functions' parameter db.Engine to context.Context
* remove some unnecessary wrap functions

... more context

(part of #9307)

* Added package store settings.

* Added models.

* Added generic package registry.

* Added tests.

* Added NuGet package registry.

* Moved service index to api file.

* Added NPM package registry.

* Added Maven package registry.

* Added PyPI package registry.

* Summary is deprecated.

* Changed npm name.

* Sanitize project url.

* Allow only scoped packages.

* Added user interface.

* Changed method name.

* Added missing migration file.

* Set page info.

* Added documentation.

* Added documentation links.

* Fixed wrong error message.

* Lint template files.

* Fixed merge errors.

* Fixed unit test storage path.

* Switch to json module.

* Added suggestions.

* Added package webhook.

* Add package api.

* Fixed swagger file.

* Fixed enum and comments.

* Fixed NuGet pagination.

* Print test names.

* Added api tests.

* Fixed access level.

* Fix User unmarshal.

* Added RubyGems package registry.

* Fix lint.

* Implemented io.Writer.

* Added support for sha256/sha512 checksum files.

* Improved maven-metadata.xml support.

* Added support for symbol package uploads.

* Added tests.

* Added overview docs.

* Added npm dependencies and keywords.

* Added no-packages information.

* Display file size.

* Display asset count.

* Fixed filter alignment.

* Added package icons.

* Formatted instructions.

* Allow anonymous package downloads.

* Fixed comments.

* Fixed postgres test.

* Moved file.

* Moved models to models/packages.

* Use correct error response format per client.

* Use simpler search form.

* Fixed IsProd.

* Restructured data model.

* Prevent empty filename.

* Fix swagger.

* Implemented user/org registry.

* Implemented UI.

* Use GetUserByIDCtx.

* Use table for dependencies.

* make svg

* Added support for unscoped npm packages.

* Add support for npm dist tags.

* Added tests for npm tags.

* Unlink packages if repository gets deleted.

* Prevent user/org delete if a packages exist.

* Use package unlink in repository service.

* Added support for composer packages.

* Restructured package docs.

* Added missing tests.

* Fixed generic content page.

* Fixed docs.

* Fixed swagger.

* Added missing type.

* Fixed ambiguous column.

* Organize content store by sha256 hash.

* Added admin package management.

* Added support for sorting.

* Add support for multiple identical versions/files.

* Added missing repository unlink.

* Added file properties.

* make fmt

* lint

* Added Conan package registry.

* Updated docs.

* Unify package names.

* Added swagger enum.

* Use longer TEXT column type.

* Removed version composite key.

* Merged package and container registry.

* Removed index.

* Use dedicated package router.

* Moved files to new location.

* Updated docs.

* Fixed JOIN order.

* Fixed GROUP BY statement.

* Fixed GROUP BY #2.

* Added symbol server support.

* Added more tests.

* Set NOT NULL.

* Added setting to disable package registries.

* Moved auth into service.

* refactor

* Use ctx everywhere.

* Added package cleanup task.

* Changed packages path.

* Added container registry.

* Refactoring

* Updated comparison.

* Fix swagger.

* Fixed table order.

* Use token auth for npm routes.

* Enabled ReverseProxy auth.

* Added packages link for orgs.

* Fixed anonymous org access.

* Enable copy button for setup instructions.

* Merge error

* Added suggestions.

* Fixed merge.

* Handle "generic".

* Added link for TODO.

* Added suggestions.

* Changed temporary buffer filename.

* Added suggestions.

* Apply suggestions from code review

Co-authored-by: Thomas Boerger <thomas@webhippie.de>

* Update docs/content/doc/packages/nuget.en-us.md

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Thomas Boerger <thomas@webhippie.de>

* Move organization related structs into sub package

* Fix test

* Fix lint

* Move more functions into sub packages

* Fix bug

* Fix test

* Update models/organization/team_repo.go

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

* Apply suggestions from code review

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

* Fix fmt

* Follow suggestion from @Gusted

* Fix test

* Fix test

* Fix bug

* Use ctx but db.DefaultContext on routers

* Fix bug

* Fix bug

* fix bug

* Update models/organization/team_user.go

* Fix bug

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

The last PR about clone buttons introduced an JS error when visiting an empty repo page:
* https://github.com/go-gitea/gitea/pull/19028
* `Uncaught ReferenceError: isSSH is not defined`, because the variables are scoped and doesn't share between sub templates.

This:
1. Simplify `templates/repo/clone_buttons.tmpl` and make code clear
2. Move most JS code into `initRepoCloneLink`
3. Remove unused `CloneLink.Git`
4. Remove `ctx.Data["DisableSSH"] / ctx.Data["ExposeAnonSSH"] / ctx.Data["DisableHTTP"]`, and only set them when is is needed (eg: deploy keys / ssh keys)
5. Introduce `Data["CloneButton*"]` to provide data for clone buttons and links
6. Introduce `Data["RepoCloneLink"]` for the repo clone link (not the wiki)
7. Remove most `ctx.Data["PageIsWiki"]` because it has been set in the `/wiki` middleware
8. Remove incorrect `quickstart` class in `migrating.tmpl`

* Avoid database lookups for `DescriptionHTML`

- Don't Compose meta's for DescriptionHTML, they are only needed in
order to correctly format and show issue's but it's highly unlikely that
a repository description will refer to a local issue.

Using 125 Connections for 5 seconds: on `/explore/repos`(which is the most
noticeable usage by this function's database lookups):

Before:

Statistics        Avg      Stdev        Max
  Reqs/sec       569.41     506.05    2715.00
  Latency      214.27ms    16.60ms   294.84ms
  HTTP codes:
    1xx - 0, 2xx - 2974, 3xx - 0, 4xx - 0, 5xx - 0
    others - 0
  Throughput:    27.17MB/s

After:

Statistics        Avg      Stdev        Max
  Reqs/sec      1585.04     789.84    4144.56
  Latency       78.89ms    15.89ms   206.94ms
  HTTP codes:
    1xx - 0, 2xx - 7975, 3xx - 0, 4xx - 0, 5xx - 0
    others - 0
  Throughput:    73.85MB/s

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: zeripath <art27@cantab.net>

- Fixes a issue with a trace of repo.Units whereby it would show the pointers.

Before:
![image](https://user-images.githubusercontent.com/25481501/155876811-036bf40e-db89-4e09-ac00-0c78ce3f5bef.png)

After:
![image](https://user-images.githubusercontent.com/25481501/155885102-16c9cf29-314b-4f32-bcee-80e332f63dec.png)

Co-authored-by: zeripath <art27@cantab.net>

This PR continues the work in #17125 by progressively ensuring that git
commands run within the request context.

This now means that the if there is a git repo already open in the context it will be used instead of reopening it.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Use conditions but not repo ids as query condition

* Improve the performance of pulls/issue

* Remove duplicated code

* fix lint

* Fix bug

* Fix stats

* More fixes

* Fix build

* Fix lint

* Fix test

* Fix build

* Adjust the logic

* Merge

* Fix conflicts

* improve the performance

* Add comments for the query conditions functions

* Some improvements

This PR contains multiple fixes. The most important of which is:

* Prevent hang in git cat-file if the repository is not a valid repository 
    
    Unfortunately it appears that if git cat-file is run in an invalid
    repository it will hang until stdin is closed. This will result in
    deadlocked /pulls pages and dangling git cat-file calls if a broken
    repository is tried to be reviewed or pulls exists for a broken
    repository.

    Fix #14734
    Fix #9271
    Fix #16113

Otherwise there are a few small other fixes included which this PR was initially intending to fix:

* Fix panic on partial compares due to missing PullRequestWorkInProgressPrefixes
* Fix links on pulls pages  due to regression from #17551 - by making most /issues routes match /pulls too - Fix #17983
* Fix links on feeds pages due to another regression from #17551 but also fix issue with syncing tags - Fix #17943
* Add missing locale entries for oauth group claims
* Prevent NPEs if ColorFormat is called on nil users, repos or teams.

* Fixes error 500 that appears when trying to browse code of a repository generated from template

* forgot to update comment

* Update models/repo/repo.go

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Update repo.go

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* some repository refactors

* remove unnecessary code

* Fix test

* Remove unnecessary banner

* Some refactors related repository model

* Move more methods out of repository

* Move repository into models/repo

* Fix test

* Fix test

* some improvements

* Remove unnecessary function