Trusted Publishing is the current best practice for publishing Python
packages. Rather than long-lived secret keys, it uses OpenID Connect
(OIDC) to allow our GitHub runner to directly authenticate itself to
PyPI and get a short-lived publishing token. This locks down publishing
quite a bit:
- There's no long-lived publish key to steal anymore.
- Publishing is *only* allowed via the *specifically designated* GitHub
workflow in the designated repo.
It also is operationally easier: no keys means there's nothing that
needs to be periodically rotated, nothing to worry about leaking, and
nobody can accidentally publish a release from their laptop because they
happened to have PyPI keys set up.
After this gets merged, we'll need to configure PyPI to start expecting
trusted publishing. It's only a few clicks and should only take a
minute; instructions are here:
https://docs.pypi.org/trusted-publishers/adding-a-publisher/
More info:
- https://blog.pypi.org/posts/2023-04-20-introducing-trusted-publishers/
- https://github.com/pypa/gh-action-pypi-publish
This is safer than the prior approach, since it's safe by default: the
release workflows never get triggered for non-merged PRs, so there's no
possibility of a buggy conditional accidentally letting a workflow
proceed when it shouldn't have.
The only loss is that publishing no longer requires a `release` label on
the merged PR that bumps the version. We can add a separate CI step that
enforces that part as a condition for merging into `master`, if
desirable.
I have discovered a bug located within `.github/workflows/_release.yml`
which is the primary cause of continuous integration (CI) errors. The
problem can be solved; therefore, I have constructed a PR to address the
issue.
## The Issue
Access the following link to view the exact errors: [Langhain Release
Workflow](https://github.com/langchain-ai/langchain/actions/workflows/langchain_release.yml)
The instances of these errors take place for **each PR** that updates
`pyproject.toml`, excluding those specifically associated with bumping
PRs.
See below for the specific error message:
```
Error: Error 422: Validation Failed: {"resource":"Release","code":"already_exists","field":"tag_name"}
```
An image of the error can be viewed here:
The `_release.yml` document contains the following if-condition:
```yaml
if: |
${{ github.event.pull_request.merged == true }}
&& ${{ contains(github.event.pull_request.labels.*.name, 'release') }}
```
## The Root Cause
The above job constantly runs as the `if-condition` is always identified
as `true`.
## The Logic
The `if-condition` can be defined as `if: ${{ b1 }} && ${{ b2 }}`, where
`b1` and `b2` are boolean values. However, in terms of condition
evaluation with GitHub Actions, `${{ false }}` is identified as a string
value, thereby rendering it as truthy as per the [official
documentation](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idif).
I have run some tests regarding this behavior within my forked
repository. You can consult my [debug
PR](https://github.com/zawakin/langchain/pull/1) for reference.
Here is the result of the tests:
|If-Condition|Outcome|
|:--:|:--:|
|`if: true && ${{ false }}`|Execution|
|`if: ${{ false }}` |Skipped|
|`if: true && false` |Skipped|
|`if: false`|Skipped|
|`if: ${{ true && false }}` |Skipped|
In view of the first and second results, we can infer that `${{ false
}}` can only be interpreted as `true` for conditions composed of some
expressions.
It is consistent that the condition of `if: ${{ inputs.working-directory
== 'libs/langchain' }}` works.
It is surprised to be skipped for the second case but it seems the spec
of GitHub Actions 😓
Anyway, the PR would fix these errors, I believe 👍
Could you review this? @hwchase17 or @shoelsch , who is the author of
[PR](https://github.com/langchain-ai/langchain/pull/360).
