1

In my Dockerfile, I have

RUN apk update && apk add tesseract-ocr=3.04

Which errors with:

unable to select packages: 
tesseract-ocr-4.1.3-r0:
breaks: world[tesseract-ocr=3.04]

I've also tried add tesseract-ocr=3.04.01, which is how it's listed on the releases page.

Simple add tesseract-ocr installs version 4.13, but I need 3.04 specifically.

ultraGentle
  • 5,084
  • 1
  • 19
  • 45

2 Answers2

0

Answer in progress:

From this question: Install older package version in Alpine

I see that each new version of Alpine updates its packages, tossing out the older versions to stay lean.

So we need to find the version of Alpine that corresponds to the date that Tesseract 3.04 was released, and use FROM Alpine:3.5 in Dockerfile.

Then add tesseract-ocr will add the only version available in that Alpine version.

It seems that Alpine 3.5 or 3.4 should have Tesseract 3.04.

EDIT: I've run into a problem, which is that FROM Alpine:3.5 fails. Investigating.

EDIT 2: the earliest official version of Alpine available on Docker Hub is 3.12, which is why alpine:3.5 fails. So...

If anyone knows a better way, please shout it out!

ultraGentle
  • 5,084
  • 1
  • 19
  • 45
  • Just a side note - the advertised supported Alpine version on Dockerhub is 3.12, but older tags are still available for download. Check the "tags" tab for the complete list of available tags: https://hub.docker.com/_/alpine?tab=tags. The oldest installable Alpine docker image is 2.6: `sudo docker run -it alpine:2.6 /bin/ash` – valiano Dec 24 '21 at 16:41
0

It's true that Alpine repositories only keep the latest version of each package, and that old package version may still be found in repositories of old Alpine versions. However, you don't necessarily need to revert to an older Alpine version as the base image. Instead, you could instruct apk to install a specific package version from the desired repository. This will work if the installed package doesn't have dependencies which conflict with other installed Alpine packages.

tesseract-ocr 3.04 is available up to Alpine 3.6:
https://pkgs.alpinelinux.org/package/v3.6/community/x86_64/tesseract-ocr

For installing it on a newer Alpine image, you should use apk's --repository parameter for specifying the 3.6 community repository. Also, make sure to specify the full version name for tessaract, which is 3.04.01-r1. For locating the exact package version number, use Alpine's package search. Putting it together:

FROM alpine:3.15
RUN apk update && apk add tesseract-ocr=3.04.01-r1 --repository=http://dl-cdn.alpinelinux.org/alpine/v3.6/community
valiano
  • 16,433
  • 7
  • 64
  • 79