Add userdef

[theAkito]

What userdef does

This tool is a more advanced adduser / useradd for your Alpine and BusyBox based Docker images.

For example, this tool may create a custom OS user with a custom ID inside pre-made Docker images, which perhaps already have a custom user defined and rebuilding the Docker image just to have your custom user in it is not an option.

https://github.com/theAkito/userdef#what

Why userdef exists

Reason 1

Now, more and more server apps try to go with the current meta of being available on Kubernetes, etc. This is a good idea, however it's often not well executed. Almost all of the popular server apps are not cloud-native. Their structure is still of some legacy kind. Examples are Mattermost, Gitea, Nextcloud. These server apps have Helm Charts available. However, applying best practices, especially the ones regarding security are not easy to achieve. Especially, when talking about the podSecurityContext. The fsGroup option is either not respected properly, which leads to broken deployments, or it's not even available and you have to add it yourself to the Helm Chart.

For example, take the Gitea Helm Chart as an example. You are allowed to set the podSecurityContext: https://gitea.com/gitea/helm-chart/src/commit/d94226765d6e1f197a3112e1b1abbcd73a8bea33/values.yaml#L19-L20

But, if you provide your custom fsGroup value, then the deployment will be broken. Why? https://github.com/go-gitea/gitea/blob/66f2210feca0b50d305a46a203c2b3d2f4d3790b/Dockerfile.rootless#L39-L48

Because the user and group ID of 1000 is hard-coded into the Docker image.

Now, imagine you have an sshfs mount, which requires you using the user of the ID 9234. The hard-coded 1000 inside the image breaks usage of this sshfs mount, just because it does not let you define a custom user with a custom ID.

To make all this work more smoothly, this tool aims to delete the existing user in that Docker image and then recreate it with your custom user, which has an ID defined by you, instead of being forced to use the randomly chosen hard-coded user ID.

Reason 2

You may just as well use this tool as a better adduser where the actual adduser or useradd (like the one in Alpine) have arbitrary and unnecessary restrictions, like for example limiting the UID/GID size to 256000.

https://github.com/theAkito/userdef#why

[theAkito]

@agebhar1

Thanks for the help. 🙂

Not sure if I understand correctly.

Do you mean something like this:

[Oracle][oracle]

So, I would need to do this:

[Akito][theAkito]

?

[agebhar1]

@theAkito

[Akito][theAkito]

exactly :+1: So, the URI exists only once. theAkito is then on the bottom of the file, like others with more than one occurence.

[theAkito]

@agebhar1

I'm still missing something, apparently...

[agebhar1]

No worries, add the line to the bottom of the the file (README.md):

[Akito]: https://github.com/theAkito

[theAkito]

@agebhar1

I've added the reference and changed both entries.

Reference

[Akito][Akito]

Target

[Akito]: https://github.com/theAkito

[agebhar1]

Thanks @theAkito :+1: