hey Dagster team, I am using Dagster Hybrid and Github Actions to deploy. the

DAGSTER_CLOUD_GIT_SHA

environment variable is perfect for my needs, except i need the temporary merge commit that is made against my base branch, rather than the commit i made and pushed. all my other deployment processes use

GITHUB_SHA

- this page talks about how

GITHUB_SHA

is this merge commit. i have tried everything i can think of, including peeking inside the deploy code called by the CLI. but the

DAGSTER_CLOUD_GIT_SHA

is always the one I pushed - the one you can see on the PR page. i don’t necessarily need to change

DAGSTER_CLOUD_GIT_SHA

- instead if you could help me pass

GITHUB_SHA

into my Dagster deployment, that’d work too! But so far I have not had luck passing build arguments into my Docker image and setting them as env variables. (side question: should i expect that env variables set in my Docker image would be accessible in my

@repository

description?) for reference, my deployment Github workflow looks very much like this one. any ideas how i can access that sha and set it as an env variable? thanks!

Have you consider just not using the github action and just using the dagster cli to deploy your code? You'd have more control over the github sha

I’ve got a big enough team of data scientists who need to test their code on branch deployments that i need to automate these deployments. I personally wouldn’t mind using the CLI, but that won’t scale well 😕

I mean using the CLI from github actions

oh gotcha. i have a command that says:

ci set-build-output --location-name=${{ matrix.location.name }} --image-tag=$IMAGE_TAG-${{ matrix.location.name }}

i don’t know this command well - is there another argument i can pass that overrides the sha?

re-read your question - it's your docker image that you're trying to insert a particular env var into?

yeah, ultimately i want this env var accessible within my

@repository

and

@job

Python scripts. i’m passing it into the Docker image and i think that should do the trick

I think that command you pointing to is just telling the dagster cloud action what image to use and what location to update - you probably have a separate step where you're actually building your docker image right? Something like

- name: Build and push fini Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          push: true
          builder: ${{ steps.buildx.outputs.name }}
          tags: "${{ env.IMAGE_REGISTRY }}:${{ github.sha }}"
          labels: |
            branch=${{ github.ref_name }}
           ...

oh yeah, i’ve got an image build step. i have been fighting the build arguments to try to get an env variable set in there

- name: Build and upload Docker image for ${{ matrix.location.name }}
  if: steps.prerun.outputs.result != 'skip'
  uses: docker/build-push-action@v4
  with:
    context: ./process
    push: true
    tags: ${{ env.IMAGE_REGISTRY }}:${{ env.IMAGE_TAG }}-${{ matrix.location.name }}
    build-args: |
      DYNAMO_TABLE_MAPPING={{ env.DYNAMO_TABLE_MAPPING }}

(Dynamo table mapping is an unrelated thing, but same concept - it requires passing an env var in) my question on that note is, am i going down the right road? if i keep fighting the build arguments and get them to work, would my jobs be able to access it?

I see but you're trying to rely on what's injected by Dagster as environment variables

perfect, thanks! i am just fighting some github workflow/Docker syntax cause it seems my argument is not being passed in correcctly. but once i get it working, i can use that as a template to also pass in the git sha. thanks @Zach!

I suspect GITHUB_SHA is reserved by Github in some fashion which is why you're having trouble overriding it - setting some other env var on the Docker image as per Zach's suggestion seems reasonable to me

I just got the env var working, so that's the way I'll go. Thanks guys!