Specify a target build stage for multi-stage Dockerfile

1

Is there any option for render.yaml, to specify multi-stage docker target?

2

Hi there,

Are you able to explain a little what you’re trying to achieve here and the use case as we may be able to offer some suggestions

3

Hi!
I have a Dockerfile with multi stages. Lets say one stage for base install, other for production, and another for development.

When building an image, docker can stop at a specific stage target.

In docker-compose.yaml it can be specified using target.

build:
  context: .
  target: prod

This feature is also available at heroku.

build:
  docker:
    release:
       dockerfile: Dockerfile
       target: builder
    web: Dockerfile

A workaround is to create separate Dockerfiles. And always using the last stage.

Thanks.

5

Hi, Render supports multi-stage docker builds. So this should work out of the box, here’s more info on Docker with Render in case it’s helpful. Deploy Docker — How to Use Docker | Render

6

Hi!
Thanks for your answer.
Indeed, render supports multi-stage builds.
What I’m looking for is the option target which is used to specify a target build stage. Instead of building entire Dockerfile including every stage.

7

hi @8tentaculos

That’s not something we currently support but I’ve added it as a feature request Support Docker Multistage target in render.yaml | Feature Requests | Render - please make sure to upvote it for later inclusion in the product.

2 Likes
8

@John_B Are we using the last target as the final target that we deployed to render?

9

We don’t support multistage targets just yet.

John B

10

It seems to work, at least for my use case.

FROM robsontenorio/laravel as base
COPY --chown=appuser:appuser . .

FROM base as local
RUN composer global require spatie/phpunit-watcher
CMD ["/usr/local/bin/start"]

FROM base as deploy
RUN chmod a+x .docker/deploy.sh
CMD ["/bin/sh", "-c", ".docker/deploy.sh && /usr/local/bin/start"]

When render starts deploy it runs ONLY first and last stages. Am I wrong?

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