mirror of
https://github.com/actions/checkout.git
synced 2024-11-22 15:37:14 +08:00
checkout v2 adr (#153)
This commit is contained in:
eric sciple
GitHub
parent
61fd8fd0c7
commit
06218e4404
199
adrs/0153-checkout-v2.md
Normal file
199
adrs/0153-checkout-v2.md
Normal file
@ -0,0 +1,199 @@
|
||||
# ADR 0153: Checkout v2
|
||||
|
||||
**Date**: 2019-10-21
|
||||
|
||||
**Status**: Accepted
|
||||
|
||||
## Context
|
||||
|
||||
This ADR details the behavior for `actions/checkout@v2`.
|
||||
|
||||
The new action will be written in typescript. We are moving away from runner-plugin actions.
|
||||
|
||||
We want to take this opportunity to make behavioral changes, from v1. This document is scoped to those differences.
|
||||
|
||||
## Decision
|
||||
|
||||
### Inputs
|
||||
|
||||
- `repository`
|
||||
- The qualified repository name (owner/repo)
|
||||
- Defaults to the workflow repo
|
||||
- `ref`
|
||||
- The ref to checkout
|
||||
- For the workflow repo, defaults to the branch and sha from the workflow event payload
|
||||
- Otherwise defaults to `master`
|
||||
- `token`
|
||||
- Defaults to the job token
|
||||
- `persist-credentials`
|
||||
- Indicates whether to embed the auth token into the git config. Allows users to script authenticated git commands.
|
||||
- Defaults to `true`
|
||||
- `clean`
|
||||
- Indicates whether to run `git clean -ffdx && git reset --hard`
|
||||
- Defaults to `true`
|
||||
- `lfs`
|
||||
- Indicates whether to download Git-LFS files
|
||||
- Defaults to `false`
|
||||
- `path`
|
||||
- Relative path under the `github.workspace` where the repository should be created
|
||||
- Defaults to the `github.workspace`
|
||||
|
||||
Note:
|
||||
- `persist-credentials` is new
|
||||
- `fetch-depth` was removed (refer [below](#fetch) for details)
|
||||
- `path` behavior is different (refer [below](#path) for details)
|
||||
- `submodules` was removed (error if specified; add later if needed)
|
||||
|
||||
### Fallback to GitHub API
|
||||
|
||||
When a sufficient version of git is not in the PATH, fallback to the [web API](https://developer.github.com/v3/repos/contents/#get-archive-link) to download a tarball/zipball.
|
||||
|
||||
Note:
|
||||
- LFS files are not included in the archive. Therefore fail if LFS is set to true.
|
||||
- Submodules are also not included in the archive. However submodules are not supported by checkout v2 anyway.
|
||||
|
||||
### Persist credentials
|
||||
|
||||
Persist the token in the git config (http.extraheader). This will allow users to script authenticated git commands, like `git fetch`.
|
||||
|
||||
A post script will remove the credentials from the git config (cleanup for self-hosted).
|
||||
|
||||
Users may opt-out by specifying `persist-credentials: false`
|
||||
|
||||
Note:
|
||||
- Users scripting `git commit` may need to set the username and email. The service does not provide any reasonable default value. Users can add `git config user.name <NAME>` and `git config user.email <EMAIL>`. We will document this guidance.
|
||||
- The auth header (stored in the repo's git config), is scoped to all of github `http.https://github.com/.extraheader`
|
||||
- Additional public remotes also just work.
|
||||
- If users want to authenticate to an additional private remote, they should provide the `token` input.
|
||||
- Lines up if we add submodule support in the future. Don't need to worry about calculating relative URLs. Just works, although needs to be persisted in each submodule git config.
|
||||
- Users opt out of persisted credentials (`persist-credentials: false`), or can script the removal themselves (`git config --unset-all http.https://github.com/.extraheader`).
|
||||
|
||||
### Fetch
|
||||
|
||||
Fetch only the SHA being built and set depth=1. This significantly reduces the fetch time for large repos.
|
||||
|
||||
If a SHA isn't available (e.g. multi repo), then fetch only the specified ref with depth=1.
|
||||
|
||||
Customers can run `git fetch --unshallow` to fetch all refs/commits. We will document this guidance.
|
||||
|
||||
Note:
|
||||
- The v1 input `fetch-depth` no longer exists. We can add this back in the future if needed.
|
||||
- Fetching a single commit is supported by Git wire protocol version 2. The git client uses protocol version 0 by default. The desired protocol version can be overridden in the git config or on the fetch command line invocation (`-c protocol.version=2`). We will override on the fetch command line, for transparency.
|
||||
- Git client version 2.18+ (released June 2018) is required for wire protocol version 2.
|
||||
|
||||
### Checkout
|
||||
|
||||
For CI, checkout will create a local ref with the upstream set. This allows users to script git as they normally would.
|
||||
|
||||
For PR, continue to checkout detached head. The PR branch is special - the branch and merge commit are created by the server. It doesn't match a users' local workflow.
|
||||
|
||||
Note:
|
||||
- Consider deleting all local refs during cleanup if that helps avoid collisions. More testing required.
|
||||
|
||||
### Path
|
||||
|
||||
For the mainline scenario, the disk-layout behavior remains the same.
|
||||
|
||||
Remember, given the repo `johndoe/foo`, the mainline disk layout looks like:
|
||||
|
||||
```
|
||||
GITHUB_WORKSPACE=/home/runner/work/foo/foo
|
||||
RUNNER_WORKSPACE=/home/runner/work/foo
|
||||
```
|
||||
|
||||
V2 introduces a new contraint on the checkout path. The location must now be under `github.workspace`. Whereas the checkout@v1 constraint was one level up, under `runner.workspace`.
|
||||
|
||||
V2 no longer changes `github.workspace` to follow wherever the self repo is checked-out.
|
||||
|
||||
These behavioral changes align better with container actions. The [documented filesystem contract](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/virtual-environments-for-github-hosted-runners#docker-container-filesystem) is:
|
||||
|
||||
- `/github/home`
|
||||
- `/github/workspace` - Note: GitHub Actions must be run by the default Docker user (root). Ensure your Dockerfile does not set the USER instruction, otherwise you will not be able to access `GITHUB_WORKSPACE`.
|
||||
- `/github/workflow`
|
||||
|
||||
Note:
|
||||
- The tracking config will not be updated to reflect the path of the workflow repo.
|
||||
- Any existing workflow repo will not be moved when the checkout path changes. In fact some customers want to checkout the workflow repo twice, side by side against different branches.
|
||||
- Actions that need to operate only against the root of the self repo, should expose a `path` input.
|
||||
|
||||
#### Default value for `path` input
|
||||
|
||||
The `path` input will default to `./` which is rooted against `github.workspace`.
|
||||
|
||||
This default fits the mainline scenario well: single checkout
|
||||
|
||||
For multi-checkout, users must specify the `path` input for at least one of the repositories.
|
||||
|
||||
Note:
|
||||
- An alternative is for the self repo to default to `./` and other repos default to `<REPO_NAME>`. However nested layout is an atypical git layout and therefore is not a good default. Users should supply the path info.
|
||||
|
||||
#### Example - Nested layout
|
||||
|
||||
The following example checks-out two repositories and creates a nested layout.
|
||||
|
||||
```yaml
|
||||
# Self repo - Checkout to $GITHUB_WORKSPACE
|
||||
- uses: checkout@v2
|
||||
|
||||
# Other repo - Checkout to $GITHUB_WORKSPACE/myscripts
|
||||
- uses: checkout@v2
|
||||
with:
|
||||
repository: myorg/myscripts
|
||||
path: myscripts
|
||||
```
|
||||
|
||||
#### Example - Side by side layout
|
||||
|
||||
The following example checks-out two repositories and creates a side-by-side layout.
|
||||
|
||||
```yaml
|
||||
# Self repo - Checkout to $GITHUB_WORKSPACE/foo
|
||||
- uses: checkout@v2
|
||||
with:
|
||||
path: foo
|
||||
|
||||
# Other repo - Checkout to $GITHUB_WORKSPACE/myscripts
|
||||
- uses: checkout@v2
|
||||
with:
|
||||
repository: myorg/myscripts
|
||||
path: myscripts
|
||||
```
|
||||
|
||||
#### Path impact to problem matchers
|
||||
|
||||
Problem matchers associate the source files with annotations.
|
||||
|
||||
Today the runner verifies the source file is under the `github.workspace`. Otherwise the source file property is dropped.
|
||||
|
||||
Multi-checkout complicates the matter. However even today submodules may cause this heuristic to be inaccurate.
|
||||
|
||||
A better solution is:
|
||||
|
||||
Given a source file path, walk up the directories until the first `.git/config` is found. Check if it matches the self repo (`url = https://github.com/OWNER/REPO`). If not, drop the source file path.
|
||||
|
||||
### Port to typescript
|
||||
|
||||
The checkout action should be a typescript action on the GitHub graph, for the following reasons:
|
||||
- Enables customers to fork the checkout repo and modify
|
||||
- Serves as an example for customers
|
||||
- Demystifies the checkout action manifest
|
||||
- Simplifies the runner
|
||||
- Reduce the amount of runner code to port (if we ever do)
|
||||
|
||||
Note:
|
||||
- This means job-container images will need git in the PATH, for checkout.
|
||||
|
||||
### Branching strategy and release tags
|
||||
|
||||
- Create a servicing branch for V1: `releases/v1`
|
||||
- Merge the changes into `master`
|
||||
- Release using a new tag `preview`
|
||||
- When stable, release using a new tag `v2`
|
||||
|
||||
## Consequences
|
||||
|
||||
- Update the checkout action and readme
|
||||
- Update samples to consume `actions/checkout@v2`
|
||||
- Job containers now require git in the PATH for checkout, otherwise fallback to REST API
|
||||
- Minimum git version 2.18
|
||||
- Update problem matcher logic regarding source file verification (runner)
|
||||
Loading…
Reference in New Issue
Block a user