- Use TXT records in order to determine the latest available version.
- This addresses a valid privacy issue, as with HTTP requests the server
can keep track(estimated) of how many instances are using Forgejo, with
DNS that's basically not possible as the server will never receive any
data, as the only ones receiving data are DNS resolvers.
(cherry picked from commit 0baefb546a)
(cherry picked from commit e8ee41880b)
(cherry picked from commit 7eca4f3bf1)
(cherry picked from commit 6dde3992dc)
(cherry picked from commit fb3a37fbfc)
(cherry picked from commit 8304af1e9d)
(cherry picked from commit 0543a7d12a)
(cherry picked from commit c3a22933b7)
(cherry picked from commit e243707694)
(cherry picked from commit 7eb6d1bcf7)
(cherry picked from commit 1d7b9535cd)
(cherry picked from commit 05920dce67)
(cherry picked from commit f173f27d7c)
(cherry picked from commit 90e1c9340e)
(cherry picked from commit de68610ea7)
(cherry picked from commit 8d5757ea04)
(cherry picked from commit c7a7fff316)
(cherry picked from commit 39ac8b8fc1)
(cherry picked from commit 9889203301)
[PRIVACY]: Adjust update checker description
- Resolves#323
- Adjust the description of the update check function on the
installation page to describe the privacy method instead of the HTTP
method by checking gitea.io
(cherry picked from commit 61eae5b105)
(cherry picked from commit 091def20a1)
(cherry picked from commit d5d11bf45a)
(cherry picked from commit 71863d4707)
(cherry picked from commit 11ece4aab1)
(cherry picked from commit afdd7e714f)
(cherry picked from commit 39170e2f1d)
(cherry picked from commit 4b3a52aab8)
(cherry picked from commit 9d763c5fc8)
(cherry picked from commit 638db15482)
(cherry picked from commit a52bfdd8e7)
(cherry picked from commit dc93d00e85)
(cherry picked from commit 0bc4b3508c)
(cherry picked from commit 3f760d85a4)
(cherry picked from commit ecc2716785)
Follow-up to d58c542579 for Forgejo.
By default, Gitea does not select any map service that can be used
to introduce a 'Show this place on a map' button in the location
field of a user profile. Before I tried upstreaming this change to
Gitea, this was the case in Forgejo. This patch essentially recovers
this functionality, which is nice for public-facing instances and
communities.
Links to original PRs:
- https://codeberg.org/forgejo/forgejo/pulls/1076
- https://github.com/go-gitea/gitea/pull/26214
(cherry picked from commit bb187d5f61)
(cherry picked from commit ce02ef9078)
(cherry picked from commit 6b75c40e25)
(cherry picked from commit 6bc8e9f573)
(cherry picked from commit 063f8afdf7)
(cherry picked from commit c5cc736b72)
(cherry picked from commit 7b1bb4bedc)
(cherry picked from commit 2a022dceb4)
(cherry picked from commit a946c142d2)
(cherry picked from commit 8a4ea0c7ab)
Part of https://github.com/go-gitea/gitea/issues/27097:
- `gitea` theme is renamed to `gitea-light`
- `arc-green` theme is renamed to `gitea-dark`
- `auto` theme is renamed to `gitea-auto`
I put both themes in separate CSS files, removing all colors from the
base CSS. Existing users will be migrated to the new theme names. The
dark theme recolor will follow in a separate PR.
## ⚠️ BREAKING ⚠️
1. If there are existing custom themes with the names `gitea-light` or
`gitea-dark`, rename them before this upgrade and update the `theme`
column in the `user` table for each affected user.
2. The theme in `<html>` has moved from `class="theme-name"` to
`data-theme="name"`, existing customizations that depend on should be
updated.
---------
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
With this PR we added the possibility to configure the Actions timeouts
values for killing tasks/jobs.
Particularly this enhancement is closely related to the `act_runner`
configuration reported below:
```
# The timeout for a job to be finished.
# Please note that the Gitea instance also has a timeout (3h by default) for the job.
# So the job could be stopped by the Gitea instance if it's timeout is shorter than this.
timeout: 3h
```
---
Setting the corresponding key in the INI configuration file, it is
possible to let jobs run for more than 3 hours.
Signed-off-by: Francesco Antognazza <francesco.antognazza@gmail.com>
If the AppURL(ROOT_URL) is an HTTPS URL, then the COOKIE_SECURE's
default value should be true.
And, if a user visits an "http" site with "https" AppURL, they won't be
able to login, and they should have been warned. The only problem is
that the "language" can't be set either in such case, while I think it
is not a serious problem, and it could be fixed easily if needed.
![image](https://github.com/go-gitea/gitea/assets/2114189/7bc9a859-dcc1-467d-bc7c-1dd6a10389e3)
This feature was removed by #22219 to avoid possible CSRF attack.
This PR takes reverseproxy auth for API back but with default disabled.
To prevent possbile CSRF attack, the responsibility will be the
reverseproxy but not Gitea itself.
For those want to enable this `ENABLE_REVERSE_PROXY_AUTHENTICATION_API`,
they should know what they are doing.
---------
Co-authored-by: Giteabot <teabot@gitea.io>
Currently, Artifact does not have an expiration and automatic cleanup
mechanism, and this feature needs to be added. It contains the following
key points:
- [x] add global artifact retention days option in config file. Default
value is 90 days.
- [x] add cron task to clean up expired artifacts. It should run once a
day.
- [x] support custom retention period from `retention-days: 5` in
`upload-artifact@v3`.
- [x] artifacts link in actions view should be non-clickable text when
expired.
This change was caused by #26271, for configuration as below:
```
[attachment]
ENABLE = true
PATH = data/attachments
MAX_SIZE = 100
MAX_FILES = 5
```
Before #26271, the resolved path is ${AppWorkPath}/${attachments.PATH}
(such as `/var/lib/gitea/data/attachments`)
After #26271, the resolved path is ${AppDataPath}/${attachments.PATH}
(such as `/var/lib/gitea/data/data/attachments`)
Fix https://github.com/go-gitea/gitea/issues/26864
Follow https://github.com/go-gitea/gitea/pull/26271
This PR is an extended implementation of #25189 and builds upon the
proposal by @hickford in #25653, utilizing some ideas proposed
internally by @wxiaoguang.
Mainly, this PR consists of a mechanism to pre-register OAuth2
applications on startup, which can be enabled or disabled by modifying
the `[oauth2].DEFAULT_APPLICATIONS` parameter in app.ini. The OAuth2
applications registered this way are being marked as "locked" and
neither be deleted nor edited over UI to prevent confusing/unexpected
behavior. Instead, they're being removed if no longer enabled in config.
![grafik](https://github.com/go-gitea/gitea/assets/47871822/81a78b1c-4b68-40a7-9e99-c272ebb8f62e)
The implemented mechanism can also be used to pre-register other OAuth2
applications in the future, if wanted.
Co-authored-by: hickford <mirth.hickford@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
---------
Co-authored-by: M Hickford <mirth.hickford@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Not too important, but I think that it'd be a pretty neat touch.
Also fixes some layout bugs introduced by a previous PR.
---------
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-authored-by: Caesar Schinas <caesar@caesarschinas.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Replace #10912
And there are many new tests to cover the CLI behavior
There were some concerns about the "option order in hook scripts"
(https://github.com/go-gitea/gitea/pull/10912#issuecomment-1137543314),
it's not a problem now. Because the hook script uses `/gitea hook
--config=/app.ini pre-receive` format. The "config" is a global option,
it can appear anywhere.
----
## ⚠️ BREAKING ⚠️
This PR does it best to avoid breaking anything. The major changes are:
* `gitea` itself won't accept web's options: `--install-port` / `--pid`
/ `--port` / `--quiet` / `--verbose` .... They are `web` sub-command's
options.
* Use `./gitea web --pid ....` instead
* `./gitea` can still run the `web` sub-command as shorthand, with
default options
* The sub-command's options must follow the sub-command
* Before: `./gitea --sub-opt subcmd` might equal to `./gitea subcmd
--sub-opt` (well, might not ...)
* After: only `./gitea subcmd --sub-opt` could be used
* The global options like `--config` are not affected
Update WorkPath/WORK_PATH related documents, remove out-dated
information.
Remove "StaticRootPath" on the admin config display page, because few
end user really need it, it only causes misconfiguration.
![image](https://github.com/go-gitea/gitea/assets/2114189/8095afa4-da76-436b-9e89-2a92c229c01d)
Co-authored-by: Giteabot <teabot@gitea.io>
Move `public/*` to `public/assets/*`
Some old PRs (like #15219) introduced inconsistent directory system.
For example: why the local directory "public" is accessed by
`http://site/assets`? How to serve the ".well-known" files properly in
the public directory?
For convention rules, the "public" directory is widely used for the
website's root directory. It shouldn't be an exception for Gitea.
So, this PR makes the things consistent:
* `http://site/assets/foo` means `{CustomPath}/public/assets/foo`.
* `{CustomPath}/public/.well-known` and `{CustomPath}/public/robots.txt`
can be used in the future.
This PR is also a prerequisite for a clear solution for:
* #21942
* #25892
* discourse.gitea.io: [.well-known path serving custom files behind
proxy?](https://discourse.gitea.io/t/well-known-path-serving-custom-files-behind-proxy/5445/1)
This PR is breaking for users who have custom "public" files (CSS/JS).
After getting approvals, I will update the documents.
----
## ⚠️ BREAKING ⚠️
If you have files in your "custom/public/" folder, please move them to
"custom/public/assets/".
---------
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Giteabot <teabot@gitea.io>
Resolve#24789
## ⚠️ BREAKING ⚠️
Before this, `DEFAULT_ACTIONS_URL` cound be set to any custom URLs like
`https://gitea.com` or `http://your-git-server,https://gitea.com`, and
the default value was `https://gitea.com`.
But now, `DEFAULT_ACTIONS_URL` supports only
`github`(`https://github.com`) or `self`(the root url of current Gitea
instance), and the default value is `github`.
If it has configured with a URL, an error log will be displayed and it
will fallback to `github`.
Actually, what we really want to do is always make it
`https://github.com`, however, this may not be acceptable for some
instances of internal use, so there's extra support for `self`, but no
more, even `https://gitea.com`.
Please note that `uses: https://xxx/yyy/zzz` always works and it does
exactly what it is supposed to do.
Although it's breaking, I belive it should be backported to `v1.20` due
to some security issues.
Follow-up on the runner side:
- https://gitea.com/gitea/act_runner/pulls/262
- https://gitea.com/gitea/act/pulls/70
Refactor `modules/indexer` to make it more maintainable. And it can be
easier to support more features. I'm trying to solve some of issue
searching, this is a precursor to making functional changes.
Current supported engines and the index versions:
| engines | issues | code |
| - | - | - |
| db | Just a wrapper for database queries, doesn't need version | - |
| bleve | The version of index is **2** | The version of index is **6**
|
| elasticsearch | The old index has no version, will be treated as
version **0** in this PR | The version of index is **1** |
| meilisearch | The old index has no version, will be treated as version
**0** in this PR | - |
## Changes
### Split
Splited it into mutiple packages
```text
indexer
├── internal
│ ├── bleve
│ ├── db
│ ├── elasticsearch
│ └── meilisearch
├── code
│ ├── bleve
│ ├── elasticsearch
│ └── internal
└── issues
├── bleve
├── db
├── elasticsearch
├── internal
└── meilisearch
```
- `indexer/interanal`: Internal shared package for indexer.
- `indexer/interanal/[engine]`: Internal shared package for each engine
(bleve/db/elasticsearch/meilisearch).
- `indexer/code`: Implementations for code indexer.
- `indexer/code/internal`: Internal shared package for code indexer.
- `indexer/code/[engine]`: Implementation via each engine for code
indexer.
- `indexer/issues`: Implementations for issues indexer.
### Deduplication
- Combine `Init/Ping/Close` for code indexer and issues indexer.
- ~Combine `issues.indexerHolder` and `code.wrappedIndexer` to
`internal.IndexHolder`.~ Remove it, use dummy indexer instead when the
indexer is not ready.
- Duplicate two copies of creating ES clients.
- Duplicate two copies of `indexerID()`.
### Enhancement
- [x] Support index version for elasticsearch issues indexer, the old
index without version will be treated as version 0.
- [x] Fix spell of `elastic_search/ElasticSearch`, it should be
`Elasticsearch`.
- [x] Improve versioning of ES index. We don't need `Aliases`:
- Gitea does't need aliases for "Zero Downtime" because it never delete
old indexes.
- The old code of issues indexer uses the orignal name to create issue
index, so it's tricky to convert it to an alias.
- [x] Support index version for meilisearch issues indexer, the old
index without version will be treated as version 0.
- [x] Do "ping" only when `Ping` has been called, don't ping
periodically and cache the status.
- [x] Support the context parameter whenever possible.
- [x] Fix outdated example config.
- [x] Give up the requeue logic of issues indexer: When indexing fails,
call Ping to check if it was caused by the engine being unavailable, and
only requeue the task if the engine is unavailable.
- It is fragile and tricky, could cause data losing (It did happen when
I was doing some tests for this PR). And it works for ES only.
- Just always requeue the failed task, if it caused by bad data, it's a
bug of Gitea which should be fixed.
---------
Co-authored-by: Giteabot <teabot@gitea.io>
In modern days, there is no reason to make users set "charset" anymore.
Close#25378
## ⚠️ BREAKING
The key `[database].CHARSET` was removed completely as every newer
(>10years) MySQL database supports `utf8mb4` already.
There is a (deliberately) undocumented new fallback option if anyone
still needs to use it, but we don't recommend using it as it simply
causes problems.
Follow up #22405Fix#20703
This PR rewrites storage configuration read sequences with some breaks
and tests. It becomes more strict than before and also fixed some
inherit problems.
- Move storage's MinioConfig struct into setting, so after the
configuration loading, the values will be stored into the struct but not
still on some section.
- All storages configurations should be stored on one section,
configuration items cannot be overrided by multiple sections. The
prioioty of configuration is `[attachment]` > `[storage.attachments]` |
`[storage.customized]` > `[storage]` > `default`
- For extra override configuration items, currently are `SERVE_DIRECT`,
`MINIO_BASE_PATH`, `MINIO_BUCKET`, which could be configured in another
section. The prioioty of the override configuration is `[attachment]` >
`[storage.attachments]` > `default`.
- Add more tests for storages configurations.
- Update the storage documentations.
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
It's been disabled by default since 1.17
(https://github.com/go-gitea/gitea/pull/18914), and it never really
delivered any benefit except being another cache layer that has its own
unsolved invalidation issues. HTTP cache works, we don't need two cache
layers at the browser for assets.
## ⚠️ BREAKING
You can remove the config `[ui].USE_SERVICE_WORKER` from your `app.ini`
now.
This addressees some things from #24406 that came up after the PR was
merged. Mostly from @delvh.
---------
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: delvh <dev.lh@web.de>
As discussed in
https://github.com/go-gitea/gitea/pull/24953#issuecomment-1565630156.
## ⚠️ BREAKING ⚠️
1. The `ui.THEME_COLOR_META_TAG` setting has been removed. If you still
need to set the `theme-color` meta tag, add it via
`$GITEA_CUSTOM/templates/custom/header.tmpl` instead.
2. The non-standard `default-theme` meta-tag added in
https://github.com/go-gitea/gitea/pull/13809 has been removed. Third
party code that needs to obtain the currently loaded theme should use
the `theme-<name>` class on the `<html>` node instead, which reflect the
currently active theme.
This adds the ability to pin important Issues and Pull Requests. You can
also move pinned Issues around to change their Position. Resolves#2175.
## Screenshots
![grafik](https://user-images.githubusercontent.com/15185051/235123207-0aa39869-bb48-45c3-abe2-ba1e836046ec.png)
![grafik](https://user-images.githubusercontent.com/15185051/235123297-152a16ea-a857-451d-9a42-61f2cd54dd75.png)
![grafik](https://user-images.githubusercontent.com/15185051/235640782-cbfe25ec-6254-479a-a3de-133e585d7a2d.png)
The Design was mostly copied from the Projects Board.
## Implementation
This uses a new `pin_order` Column in the `issue` table. If the value is
set to 0, the Issue is not pinned. If it's set to a bigger value, the
value is the Position. 1 means it's the first pinned Issue, 2 means it's
the second one etc. This is dived into Issues and Pull requests for each
Repo.
## TODO
- [x] You can currently pin as many Issues as you want. Maybe we should
add a Limit, which is configurable. GitHub uses 3, but I prefer 6, as
this is better for bigger Projects, but I'm open for suggestions.
- [x] Pin and Unpin events need to be added to the Issue history.
- [x] Tests
- [x] Migration
**The feature itself is currently fully working, so tester who may find
weird edge cases are very welcome!**
---------
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Giteabot <teabot@gitea.io>
1. non-dev mode is treated as prod mode, to protect users from
accidentally running in dev mode if there is a typo in this value.
2. in dev mode, do not need to really exit if there are template errors,
because the template errors could be fixed by developer soon and the
templates get reloaded, help:
* https://github.com/go-gitea/gitea/issues/24845#issuecomment-1557615382
3. Fine tune the mail template loading message.
Close#13454 , Close#23255, Close#14697 (and maybe more related
issues)
Many users have the requirement to customize the git config. This PR
introduces an easy way: put the options in Gitea's app.ini
`[git.config]`, then the config options will be applied to git config.
And it can support more flexible default config values, eg: now
`diff.algorithm=histogram` by default. According to:
https://stackoverflow.com/a/32367597/4754037 , `histogram diff` is
efficient and doesn't like to cause server-side problems.
---------
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: Giteabot <teabot@gitea.io>
Replace #20257 (which is stale and incomplete)
Close#20255
Major changes:
* Deprecate the "WHITELIST", use "ALLOWLIST"
* Add wildcard support for EMAIL_DOMAIN_ALLOWLIST/EMAIL_DOMAIN_BLOCKLIST
* Update example config file and document
* Improve tests
## ⚠️ Breaking
The `log.<mode>.<logger>` style config has been dropped. If you used it,
please check the new config manual & app.example.ini to make your
instance output logs as expected.
Although many legacy options still work, it's encouraged to upgrade to
the new options.
The SMTP logger is deleted because SMTP is not suitable to collect logs.
If you have manually configured Gitea log options, please confirm the
logger system works as expected after upgrading.
## Description
Close#12082 and maybe more log-related issues, resolve some related
FIXMEs in old code (which seems unfixable before)
Just like rewriting queue #24505 : make code maintainable, clear legacy
bugs, and add the ability to support more writers (eg: JSON, structured
log)
There is a new document (with examples): `logging-config.en-us.md`
This PR is safer than the queue rewriting, because it's just for
logging, it won't break other logic.
## The old problems
The logging system is quite old and difficult to maintain:
* Unclear concepts: Logger, NamedLogger, MultiChannelledLogger,
SubLogger, EventLogger, WriterLogger etc
* Some code is diffuclt to konw whether it is right:
`log.DelNamedLogger("console")` vs `log.DelNamedLogger(log.DEFAULT)` vs
`log.DelLogger("console")`
* The old system heavily depends on ini config system, it's difficult to
create new logger for different purpose, and it's very fragile.
* The "color" trick is difficult to use and read, many colors are
unnecessary, and in the future structured log could help
* It's difficult to add other log formats, eg: JSON format
* The log outputer doesn't have full control of its goroutine, it's
difficult to make outputer have advanced behaviors
* The logs could be lost in some cases: eg: no Fatal error when using
CLI.
* Config options are passed by JSON, which is quite fragile.
* INI package makes the KEY in `[log]` section visible in `[log.sub1]`
and `[log.sub1.subA]`, this behavior is quite fragile and would cause
more unclear problems, and there is no strong requirement to support
`log.<mode>.<logger>` syntax.
## The new design
See `logger.go` for documents.
## Screenshot
<details>
![image](https://github.com/go-gitea/gitea/assets/2114189/4462d713-ba39-41f5-bb08-de912e67e1ff)
![image](https://github.com/go-gitea/gitea/assets/2114189/b188035e-f691-428b-8b2d-ff7b2199b2f9)
![image](https://github.com/go-gitea/gitea/assets/2114189/132e9745-1c3b-4e00-9e0d-15eaea495dee)
</details>
## TODO
* [x] add some new tests
* [x] fix some tests
* [x] test some sub-commands (manually ....)
---------
Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Giteabot <teabot@gitea.io>
fix#12192 Support SSH for go get
---------
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>
Co-authored-by: mfk <mfk@hengwei.com.cn>
Co-authored-by: silverwind <me@silverwind.io>
According to the discussion with DanielGibson, the default "20m" seems
too short. It would make LFS fail if the file is large / network is
slow.
I think relaxing this timeout doesn't have side affect. So change the
default value to 24h, IMO that should be long enough.
## ⚠️ BREAKING
If admins want the previous timeout, they should set the setting
`[server].LFS_HTTP_AUTH_EXPIRY`.
# ⚠️ Breaking
Many deprecated queue config options are removed (actually, they should
have been removed in 1.18/1.19).
If you see the fatal message when starting Gitea: "Please update your
app.ini to remove deprecated config options", please follow the error
messages to remove these options from your app.ini.
Example:
```
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].ISSUE_INDEXER_QUEUE_TYPE`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].UPDATE_BUFFER_LEN`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [F] Please update your app.ini to remove deprecated config options
```
Many options in `[queue]` are are dropped, including:
`WRAP_IF_NECESSARY`, `MAX_ATTEMPTS`, `TIMEOUT`, `WORKERS`,
`BLOCK_TIMEOUT`, `BOOST_TIMEOUT`, `BOOST_WORKERS`, they can be removed
from app.ini.
# The problem
The old queue package has some legacy problems:
* complexity: I doubt few people could tell how it works.
* maintainability: Too many channels and mutex/cond are mixed together,
too many different structs/interfaces depends each other.
* stability: due to the complexity & maintainability, sometimes there
are strange bugs and difficult to debug, and some code doesn't have test
(indeed some code is difficult to test because a lot of things are mixed
together).
* general applicability: although it is called "queue", its behavior is
not a well-known queue.
* scalability: it doesn't seem easy to make it work with a cluster
without breaking its behaviors.
It came from some very old code to "avoid breaking", however, its
technical debt is too heavy now. It's a good time to introduce a better
"queue" package.
# The new queue package
It keeps using old config and concept as much as possible.
* It only contains two major kinds of concepts:
* The "base queue": channel, levelqueue, redis
* They have the same abstraction, the same interface, and they are
tested by the same testing code.
* The "WokerPoolQueue", it uses the "base queue" to provide "worker
pool" function, calls the "handler" to process the data in the base
queue.
* The new code doesn't do "PushBack"
* Think about a queue with many workers, the "PushBack" can't guarantee
the order for re-queued unhandled items, so in new code it just does
"normal push"
* The new code doesn't do "pause/resume"
* The "pause/resume" was designed to handle some handler's failure: eg:
document indexer (elasticsearch) is down
* If a queue is paused for long time, either the producers blocks or the
new items are dropped.
* The new code doesn't do such "pause/resume" trick, it's not a common
queue's behavior and it doesn't help much.
* If there are unhandled items, the "push" function just blocks for a
few seconds and then re-queue them and retry.
* The new code doesn't do "worker booster"
* Gitea's queue's handlers are light functions, the cost is only the
go-routine, so it doesn't make sense to "boost" them.
* The new code only use "max worker number" to limit the concurrent
workers.
* The new "Push" never blocks forever
* Instead of creating more and more blocking goroutines, return an error
is more friendly to the server and to the end user.
There are more details in code comments: eg: the "Flush" problem, the
strange "code.index" hanging problem, the "immediate" queue problem.
Almost ready for review.
TODO:
* [x] add some necessary comments during review
* [x] add some more tests if necessary
* [x] update documents and config options
* [x] test max worker / active worker
* [x] re-run the CI tasks to see whether any test is flaky
* [x] improve the `handleOldLengthConfiguration` to provide more
friendly messages
* [x] fine tune default config values (eg: length?)
## Code coverage:
![image](https://user-images.githubusercontent.com/2114189/236620635-55576955-f95d-4810-b12f-879026a3afdf.png)