Added docker files to build znc for arm arch

[rubemlrm]

Added dockerfile for arm architure on slim and full directorys
Added run command to make docker-entrypoint.sh as executable so we dont get a permissions denied error

[DarthGandalf]

It's already executable...

[rubemlrm]

When i've tried build the image for arm , i've got some errors relative to this, saying that i dont have permissions to run the script. After i've added this line , the error was fixed .

[DarthGandalf]

Maybe you accidentally cleared the executable bit from the file in your git checkout before building the image? Or some strange filesystem you use did that for you?

[rubemlrm]

I will try build the image again on my rpi and my laptop to see if this occurs again.

[DarthGandalf]

I'd prefer to avoid the exact copy of amd64 Dockerfile. Do you know that in case of such copypaste the copies will always diverge, and various changes will accidentally go to only one copy?

[DarthGandalf]

I don't see any arm in https://github.com/docker-library/official-images/tree/master/library
How is this going to work?

[rubemlrm]

@DarthGandalf relative to the last point , i dont really understand your question :/ can you explain better ?

[DarthGandalf]

This image is published on docker as "official" at https://hub.docker.com/_/znc/
Check https://docs.docker.com/docker-hub/official_repos/ for details.

I see ARM mentioned in https://github.com/docker-library/official-images#architectures-other-than-amd64 but I don't see where it refers to Dockerfile.armhf. How this is going to be published on docker hub?

Related: why only arm6, but no arm7 or arm8?

[rubemlrm]

so @DarthGandalf in your opinion wich is the best approach i can take to try port znc to a arm arch and became a official build ?

[DarthGandalf]

@rubemlrm start with investigating how to make it acceptable as an official build :)

My wishlist:

• Don't forget various variants of ARM architecture
• Find some way to not have duplication of the same code in different files (if it doesn't contradict requirements imposed by making it official)

@yosifkit @tianon can you give any advice about official non-amd64 images?

Thanks!

[tianon]

My advice would be to stay away from multiple Dockerfiles as much as possible -- in our experience converting many of the docker-library official images over to support multiple architectures, a single Dockerfile is much easier to maintain and review, and our tooling is able to adjust the FROM for now while we get manifest lists in place to ease that requirement too (docker-library/official-images#2289).

See docker-library/python#198 (and some of the cross-linked PRs) for our suggested method for adding an appropriate --build value on ./configure, and docker-library/buildpack-deps#59 (and cross-linked PRs) for a way to add an appropriate value for Architectures in the library/znc file.

An easy way to do a rough sanity test for the multiarch Dockerfile is to adjust the FROM to start with i386/ so that you can build the 32bit version (which should build just fine on any modern amd64 CPU) -- that should help catch the types of issues you're likely to run into on other arches like ARM (32 and 64), POWER 8, or System Z. 👍

[DarthGandalf]

This is fixed, via 7f4f142 and docker-library/official-images#3874