docs: add dco / rerere doc (#784)

part of #423

docs/README.md

@@ -15,7 +15,7 @@
 以下展示的是 TiDB 社区当中较为常用的一些组件或插件，其中名称以 `ti-community-` 开头的外部插件是 TiDB 社区 [Community Infra SIG](https://developer.tidb.io/SIG/community-infra) 开发并正在维护的插件。如果你在使用过程中遇到任何问题，你都可以在 [Slack](https://slack.tidb.io/invite?team=tidb-community&channel=sig-community-infra&ref=github) 当中与我们取得联系。
 
 | 插件名称                        | 插件类型 | 功能简介                                                                                      |
-| ------------------------------- | -------- | --------------------------------------------------------------------------------------------- |
+|---------------------------------|----------|-----------------------------------------------------------------------------------------------|
 | tide                            | 基础组件 | 通过一些给定条件来管理 GitHub PR 池，自动合并符合条件的 PR。                                  |
 | rerere                          | 基础组件 | 将代码 push 到专门用来重新测试的分支上进行重新测试。                                          |
 | ti-community-owners             | 外部插件 | 根据 SIG 或 Github 权限等信息来确定 PR 的 reviewer 和 committer。                             |
@@ -28,7 +28,7 @@
 | ti-community-label-blocker      | 外部插件 | 主要负责阻止用户对某些敏感标签的进行非法操作。                                                |
 | ti-community-label-contribution | 外部插件 | 主要负责为外部贡献者的 PR 添加 `contribution` 或 `first-time-contributor` 标签。              |
 | ti-community-cherrypicker       | 外部插件 | 主要负责将 PR cherry-pick 到其他目标分支。                                                    |
-| ti-community-format-checker     | 外部插件 | 主要负责将 PR 或 Issue 的标题、内容以及提交信息的格式进行检查。                                    |
+| ti-community-format-checker     | 外部插件 | 主要负责将 PR 或 Issue 的标题、内容以及提交信息的格式进行检查。                               |
 | needs-rebase                    | 外部插件 | 当 PR 需要进行 rebase 时，通过添加标签或添加评论提醒 PR 作者进行 rebase。                     |
 | require-matching-label          | 内置插件 | 当 PR 或 Issue 缺失相关标签时，通过添加标签或评论提醒贡献者进行补充。                         |
 | hold                            | 内置插件 | 通过 `/[un]hold` 命令，添加或取消 PR 的不可合并状态。                                         |
@@ -38,6 +38,7 @@
 | wip                             | 内置插件 | 为正在开发的 PR 添加 `do-not-merge/work-in-progress` 标签，阻止自动分配 reviewer 和 PR 合并。 |
 | welcome                         | 内置插件 | 通过机器人向首次贡献的贡献者发送欢迎语。                                                      |
 | release-note                    | 内置插件 | 主要负责检测 PR 是否添加了发布说明。                                                          |
+| dco                             | 内置插件 | 检查 PR 的所有 commit 是否都签署邮箱地址。                                                    |
 | label_sync                      | 工具     | 能够将 yaml 文件当中配置的标签同步到一个或多个仓库。                                          |
 | autobump                        | 工具     | 通过自动提交 Pull Request 的方式更新上游 Prow 及其相关组件和插件的版本。                      |
 

docs/_sidebar.md

@@ -22,6 +22,7 @@
     - [assign](plugins/assign.md)
     - [milestone](plugins/milestone.md)
     - [release-note](plugins/release-note.md)
+    - [dco](plugins/dco.md)
 - [工具](tools.md)
   - [label_sync](tools/label_sync.md)
   - [autobump](tools/autobump.md)

docs/components/rerere.md

@@ -13,12 +13,12 @@
 
 为了解决上述问题我们开发了 [tars](plugins/tars.md) 来自动的合并最新 的 Base 分支到 PR，这样能解决问题，但是对于大型仓库来说这不是一个高效的解决方案。**例如有 n 个同时可以 merge 的 PR，那就要跑 O(n^2) 次测试，大大浪费了 CI 资源。**
 
-为了高效的合并 PR，并且节省测试资源，我们提出了[多个解决方案](https://github.com/ti-community-infra/rfcs/discussions/13)。最终决定利用 Prow Job 结合 Tide 来解决该问题。
+为了高效的合并 PR，并且节省测试资源，我们提出了[多个解决方案](https://github.com/ti-community-infra/rfcs/discussions/13) 。最终决定利用 Prow Job 结合 Tide 来解决该问题。
 
 ## 设计思路
 
 1. Prow Job 会利用 [clonerefs](https://github.com/kubernetes/test-infra/tree/master/prow/clonerefs) 工具将 PR 和最新的 Base 分支合并之后克隆到运行测试的 Pod，所以我们总是能够获取到已经合并了最新 Base 的代码库，rerere 可以将该代码 push 到重新测试分支进行合并之前的测试。
-2. Porw Job 可以设置 max_concurrency 来控制该 CI 任务最多的执行个数，这是一个天然的 FIFO 队列，我们可以利用该功能对重新测试任务排队。
+2. Porw Job 可以设置 `max_concurrency` 来控制该 CI 任务最多的执行个数，这是一个天然的 FIFO 队列，我们可以利用该功能对重新测试任务排队。
 3. Tide 在代码合并之前，会检测所有的 Prow Job 是否都使用了最新的 Base 进行了测试。如果当前 CI Pod 使用的不是最新的 Base，Tide 会自动重新触发该测试，这样就确保了所有的 PR 在合并之前都会用最新的 Base 重新测试。
 4. 在 rerere 中我们会将代码 push 到指定的测试分支，然后定期检查要求的 CI 是否都已经通过，当所有要求的 CI 都通过时，我们 rerere 的 Prow Job 就会通过测试。Tide 则会自动合并当前 PR。
 

docs/en/README.md

@@ -16,31 +16,33 @@ The TiDB community has customized a number of its own plugins based on this feat
 
 The following shows some commonly used components or plugins in the TiDB community. The external plugins whose name begin with `ti-community-` are developed and maintained by the [Community Infra SIG](https://developer.tidb.io/SIG/community-infra) of TiDB community. If you encounter any problems during use, you can contact us in [Slack](https://slack.tidb.io/invite?team=tidb-community&channel=sig-community-infra&ref=github).
 
-| plugin name                 | plugin type     | introduction                                                                                                                              |
-|-----------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------|
-| tide                        | basic component | Manage the GitHub PR pool through some given conditions and automatically merge PR that meets the conditions.                             |
-| ti-community-owners         | external plugin | Determine the reviewer and committer of the PR based on information such as SIG or Github permissions.                                    |
-| ti-community-lgtm           | external plugin | Add, update or delete the `status/LGT*` label by submitting Approve or Request Changes review.                                            |
-| ti-community-merge          | external plugin | Add or delete the `status/can-merge` label for PR by command.                                                                             |
-| ti-community-blunderbuss    | external plugin | Mainly responsible for automatically assigning reviewers based on SIG or Github permissions.                                              |
-| ti-community-autoresponder  | external plugin | Automatically reply based on the content of the comment.                                                                                  |
-| ti-community-tars           | external plugin | Mainly responsible for automatically merging the main branch into the current PR to ensure that the current PR's Base is kept up to date. |
-| ti-community-label          | external plugin | Add labels to PR or Issue via commands.                                                                                                   |
-| ti-community-label-blocker  | external plugin | Mainly responsible for preventing users from illegal operations on certain sensitive labels.                                              |
-| ti-community-contribution   | external plugin | Mainly responsible for adding `contribution` or `first-time-contributor` labels to the PRs of external contributors.                      |
-| ti-community-cherrypicker   | external plugin | Mainly responsible for cherry-pick PR to other target branches.                                                                           |
-| ti-community-format-checker | external plugin | Mainly responsible for checking the title, content and format of the commit message of the PR or issue.                                   |
-| needs-rebase                | external plugin | When the PR needs to rebase, add labels or add comments to remind the PR author to rebase.                                                |
-| require-matching-label      | internal plugin | When a PR or Issue lacks a relevant label, add a label or comment to remind contributors to supplement.                                   |
-| hold                        | internal plugin | Add or cancel the non-combinable status of PR through the `/[un]hold` command.                                                            |
-| assign                      | internal plugin | Add or cancel the assignee of PR or Issue through the `/[un]assign` command.                                                              |
-| size                        | internal plugin | Evaluate the size of the PR based on the number of lines of code modification, and label the PR with `size/*`.                            |
-| lifecycle                   | internal plugin | Use labels to mark the life cycle of Issue or PR.                                                                                         |
-| wip                         | internal plugin | Add the `do-not-merge/work-in-progress` label to the PR under development to prevent the automatic assignment of reviewer and PR merge.   |
-| welcome                     | internal plugin | Send a welcome message to contributors who have contributed for the first time through a robot.                                           |
-| release-note                | internal plugin | It is mainly responsible for detecting whether a PR has added a release note.                                                             |
-| label_sync                  | tool            | Able to synchronize the labels configured in the yaml file to one or more repositories.                                                   |
-| autobump                    | tool            | Update the version of upstream Prow and its related components and plugins by automatically submitting Pull Requests.                     |
+| plugin name                 | plugin type     | introduction                                                                                                                                                |
+|-----------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| tide                        | basic component | Manage the GitHub PR pool through some given conditions and automatically merge PR that meets the conditions.                                               |
+| rerere                      | basic component | Push the code to a branch dedicated to re-testing for re-testing.                                                                                           |
+| ti-community-owners         | external plugin | Determine the reviewer and committer of the PR based on information such as SIG or Github permissions.                                                      |
+| ti-community-lgtm           | external plugin | Add, update or delete the `status/LGT*` label by submitting Approve or Request Changes review.                                                              |
+| ti-community-merge          | external plugin | Add or delete the `status/can-merge` label for PR by command.                                                                                               |
+| ti-community-blunderbuss    | external plugin | Mainly responsible for automatically assigning reviewers based on SIG or Github permissions.                                                                |
+| ti-community-autoresponder  | external plugin | Automatically reply based on the content of the comment.                                                                                                    |
+| ti-community-tars           | external plugin | Mainly responsible for automatically merging the main branch into the current PR to ensure that the current PR's Base is kept up to date.                   |
+| ti-community-label          | external plugin | Add labels to PR or Issue via commands.                                                                                                                     |
+| ti-community-label-blocker  | external plugin | Mainly responsible for preventing users from illegal operations on certain sensitive labels.                                                                |
+| ti-community-contribution   | external plugin | Mainly responsible for adding `contribution` or `first-time-contributor` labels to the PRs of external contributors.                                        |
+| ti-community-cherrypicker   | external plugin | Mainly responsible for cherry-pick PR to other target branches.                                                                                             |
+| ti-community-format-checker | external plugin | Mainly responsible for checking the title, content and format of the commit message of the PR or issue.                                                     |
+| needs-rebase                | external plugin | When the PR needs to rebase, add labels or add comments to remind the PR author to rebase.                                                                  |
+| require-matching-label      | internal plugin | When a PR or Issue lacks a relevant label, add a label or comment to remind contributors to supplement.                                                     |
+| hold                        | internal plugin | Add or cancel the non-combinable status of PR through the `/[un]hold` command.                                                                              |
+| assign                      | internal plugin | Add or cancel the assignee of PR or Issue through the `/[un]assign` command.                                                                                |
+| size                        | internal plugin | Evaluate the size of the PR based on the number of lines of code modification, and label the PR with `size/*`.                                              |
+| lifecycle                   | internal plugin | Use labels to mark the life cycle of Issue or PR.                                                                                                           |
+| wip                         | internal plugin | Add the `do-not-merge/work-in-progress` label to the PR under development to prevent the automatic assignment of reviewer and PR merge.                     |
+| welcome                     | internal plugin | Send a welcome message to contributors who have contributed for the first time through a robot.                                                             |
+| release-note                | internal plugin | It is mainly responsible for detecting whether a PR has added a release note.                                                                               |
+| dco                         | internal plugin | Check whether all commits of the PR have signed off by email addresses.                                                                                     |
+| label_sync                  | tool            | Able to synchronize the labels configured in the yaml file to one or more repositories.                                                                     |
+| autobump                    | tool            | Update the version of upstream Prow and its related components and plugins by automatically submitting Pull Requests.                                       |
 
 At the same time, you can find all currently available components or plugins in [Plugins](https://prow.tidb.io/plugins) page, or in [Command](https://prow.tidb.io/command-help) to view the commands available in the specified repository.
 

docs/en/_sidebar.md

@@ -1,5 +1,6 @@
 - [Components](en/components.md)
   - [Tide](en/components/tide.md)
+  - [rerere](en/components/rerere.md)
 - [Plugins](en/plugins.md)
   - External
     - [ti-community-owners](en/plugins/owners.md)
@@ -21,6 +22,7 @@
     - [assign](en/plugins/assign.md)
     - [milestone](en/plugins/milestone.md)
     - [release-note](en/plugins/release-note.md)
+    - [dco](en/plugins/dco.md)
 - [tools](tools.md)
   - [label_sync](en/tools/label_sync.md)
   - [autobump](en/tools/autobump.md)