Dockerfile update

[joschrew]

This PR is part of series to offer single ocrd modules as Docker Containers (ocrd slim containers) to be used with ocr-d network.

[stweil]

If similar changes are made for more processors, new releases of OCR-D would require a lot of additional work.

[bertsky]

In principle – yes. But practically, the opposite is true – without pinning to a specific version, the module maintainers are always forced to react timely to things broken by upstream OCR-D. By pinning, we the maintainer can make a conscious decision on whether and when to update.

Of course, we should at some point do the same thing with pure Python requirements. But for native installation (or ocrd_all via Docker) we currently cannot, because as long as our packages will live in a large unisolated venv, pinning would immediately shrink the intersection of compatible versions to zero. On the other hand, Docker modules are the way to go for greater isolation, and pinning here will now on offer some protection against breaking changes.

[kba]

Yeah, I think the added effort of hardcoding a specific version is worth the reproducibility and since it does not concern the deployment with ocrd_all (yet), I see no reason not to.

[bertsky]

you also might want to make the same modification (labels) to the build-olena.dockerfile (which is Olena-only, without OCR-D wrapper).

Also, perhaps it's time to make this a single proper multi-stage Dockerfile...

[joschrew]

Just to confirm, do you think this is ready to be merged? I realized I probably could merge it myself which I would try to do if so. I agree that a multi stage build would be nice. I looked into it but I think I cannot do it and I think this could be regarded as another separate issue. And to me it is not clear what the advantage of the olena-only image is except from size.
Its really nice with the other images like ocrd_tesserocr up to date in docker-hub and the possibility to use that instead of self building ...

[kba]

this could be regarded as another separate issue

#97

Just to confirm, do you think this is ready to be merged? I realized I probably could merge it myself which I would try to do if so.

Yes, I think it's ready for merge and will do so later, thank you!

[bertsky]

@kba do you have any idea what might be the problem with the Dockerhub deployment?

On CircleCI build-docker, I see

unauthorized: incorrect username or password

But the credentials have not been touched in 9 months, nor has the CI config changed in 2 years...