Refresh preview option

[michal-bajer1]

Hello!

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Issue details

I would like to build a Github workflow, which would regularly run preview of stack refresh and create an issue in the repository, if some changes between stack and our cloud provider are found.

Affected area/feature

The options of the refresh or preview command, so that the equivalent of pulumi preview --refresh can be executed.

[dixler]

Hi. That's an interesting idea. I'm not too familiar with the actions side of things, but from https://github.com/pulumi/actions#configuration it seems like the following would accomplish what you're asking.

      - uses: pulumi/actions@v4
        with:
          command: preview
          refresh: true
        ...

If you need something more than that from the action, can you explain further what you might need?

[michal-bajer1]

Hi, there is a subtle difference there.
I tried this option, but what happens is that it runs refresh, stores the results into the stack and then it runs preview. But I don't really want the state of the stack to change unpredictably. What pulumi preview --refresh does is effectively preview of code vs cloud provider, but it doesn't change the state of the stack.

[peterstockwell-sagov]

Hello, we would also like an option to perform a preview with a refresh without updating the stack, although our use case is a little different. We run pulumi previews as part of our CI checks, however because the refresh option updates the stack, if multiple PRs are opened or updated at around the same time, one of the PR checks will fail as only one update can be performed on a stack at a time and requiring us to rerun it manually. Having the refresh run without updating the stack would solve this issue for us. We have raised this issue with @aureq privately already.

I saw @RobbieMcKinstry has commented in another issue about adding an option for raw as a command. I believe this would work for us and would be happy to implement and submit a PR with those changes if it helps.

[RobbieMcKinstry]

Hi Peter (@peterstockwell-sagov),
Sorry for the slow response; we'd be happy to accept a PR for the raw command. :-)

if multiple PRs are opened or updated at around the same time, one of the PR checks will fail as only one update can be performed on a stack at a time

When I read this, my mind lept to GitHub Action's concurrency blocks. (Forgive me if you've already considered this.) At the granularity of jobs, you can block jobs from running at the same time if they're both PRs to the same base_ref, for instance.

---

I think @michal-bajer1 identified some very confusing behavior. It's confusing (to me) that…

- uses: pulumi/actions@v4
  command: preview
  refresh: true

…runs…

$ pulumi refresh; pulumi preview

instead of...

$ pulumi preview --refresh

If I had wanted the chaining behavior, I would have thought we'd chain the operations in the YAML instead:

- uses: pulumi/actions@v4
  command: refresh
- uses: pulumi/actions@v4
  command: preview

This is made even more confusing by pulumi/pulumi#10967

Unfortunately, I don't think we have a way to repair this behavior without redefining the behavior of refresh: true.
That leads me to believe @peterstockwell-sagov 's suggestion of adding a raw command would be the way forward here.

[michal-bajer1]

@RobbieMcKinstry It definitely confused me at first :)

I guess you could try to introduce something like:

refresh-before-update: true - alias refresh: true
preview-including-refresh: true

But it isn't pretty :(

[RobbieMcKinstry]

If I weren't worried about breaking changes, I would prefer to just drop the refresh-before-update behavior entirely, and suggest users use the @pulumi/action twice: once with command: refresh and once again with their intended behavior.

But you're right, that's an approach that would clarify the behavior without a breaking change :)

[simenandre]

As there is no way to get the Automation API to run pulumi preview --refresh, we cannot do it with Automation API (which is why we did the weird pulumi refresh first).

Our intention was back then to do the --refresh argument precisely, but AFAIK, it still isn't available in Automation API.

I would love to see an idea for implementing raw command somehow smoothly. Might make sense to use the getExecOutput function that is included in @actions/exec and get the output that way. Let me know I can help!

[RobbieMcKinstry]

As there is no way to get the Automation API to run pulumi preview --refresh, we cannot do it with Automation API (which is why we did the weird pulumi refresh first).

That makes sense! However, I think we could fix that problem ;D If we add the --refresh flag to the Automation API, then it sounds like we can resolve the issue by removing the refresh chaining and replacing it with the --refresh flag.

[RobbieMcKinstry]

I opened pulumi/pulumi#12740 to address the missing flag in Automation API.

[arealmaas]

Any update to this? Would definitely like to see the same, and it seems like the pull request is merged now 🙏

[RobbieMcKinstry]

Hi @arealmaas. Thanks for reaching out and expressing your interest ❤️
I'm no longer an OSS maintainer for this repository, so I'm afraid I'm no longer the point of contact for this issue. @simenandre (also from Oslo!) and the Pulumi Core team are currently leading the charge! 💪🏻

[simenandre]

Hello 👋

I will have a look into this very soon! 🚀

[fitz-vivodyne]

Is this still on the roadmap/happening very soon?

[fitz-vivodyne]

Took an initial stab at this in #1118 without knowing what I'm doing.

In a future major release it might make sense to change the behavior of the refresh option to use the --refresh flag, but for now I'm proposing a soft-refresh option in addition to refresh.