Allow multistage Dockerfile

[FlorianIkarus]

As much as I understand the reason for verifying the Docker image name in the Dockerfile, the current approach makes multistage Dockerfiles impossible.

Example:

FROM cloudblueconnect/connect-extension-runner:28.7 AS build
...
FROM build AS deploy
...

Please modify the validation in connect/eaas/core/validation/validators/base.py/validate_docker_compose_yml, so that it removes the AS <stage name> part (if existing) of the FROM line and then compares it to the pre-calculated image name.

[FlorianIkarus]

For further information about multi-staging, please refer to the Docker manual:
https://docs.docker.com/build/building/multi-stage/

[Sainomori]

Hi @FlorianIkarus ,

Thanks for sharing your concern. We're aware of the issue you've highlighted and its impact on multistage Dockerfiles. Our team is actively investigating a solution that provides better support for these scenarios.

Stay tuned for updates as we work to address this. Your feedback is greatly appreciated.