docker build scripts assume user id to be 1000 (uid)

[SomberNight]

I recently realised that most of our build scripts only work when run with uid==1000.
I guess this just happens to be the case for everyone who cares to run them. :P

The issue is that we mount the local git clone with docker run -v and work on that directly:

electrum/contrib/build-wine/build.sh

Lines 47 to 49 in d8abab3

	docker run -it \
	--name electrum-wine-builder-cont \
	-v "$PROJECT_ROOT_OR_FRESHCLONE_ROOT":/opt/wine64/drive_c/electrum \

Inside the container, the local git clone will have numerically the same uid/gid owner.
The unix user inside the container is created via useradd, and this starts numbering uids from 1000.

electrum/contrib/build-wine/Dockerfile

Line 66 in d8abab3

RUN useradd --create-home --shell /bin/bash ${USER}

So due to the -v mount, the unix user inside the container needs matching user id with the host unix user, and due to the useradd, the container's unix user will have uid==1000, hence the host unix user also needs to have uid==1000.

I guess this is likely a regression from #7697.
Not clear how to fix cleanly.

related:
moby/moby#7198
https://stackoverflow.com/q/39397548
https://stackoverflow.com/a/45640469
coder/code-server#439

[accumulator]

alternative solution: use uid from user building the containers as the build container's uid

https://github.com/accumulator/electrum/tree/build_uid_from

[accumulator]

Note: Might be problematic w.r.t reproducibility

[SomberNight]

use uid from user building the containers as the build container's uid

Great idea!

Might be problematic w.r.t reproducibility

Indeed. I was also thinking about that...

We can differentiate local dev builds and reproducible builds, and only use your idea in the former case though.
I cherry-picked your change and added some more changes, see #8267

[SomberNight]

Btw, just as context, I bumped into this bug and want to fix it now as I have set up a server I would like to build on but am already using userid=1000 for other things.

[assorted-casuals]

not sure if related, but attempting a fresh build on (lubuntu 22.04) results in error.

current ID 1000,

$ ./build.sh                                                  
💬 INFO:  Found 12 CPUs, which we might use for building.
💬 INFO:  building docker image.
[+] Building 400.5s (10/14)                                   docker:default
 => [internal] load build definition from Dockerfile                    0.3s
 => => transferring dockerfile: 2.49kB                                  0.0s
 => [internal] load metadata for docker.io/library/debian:buster@sha25  6.1s
 => [internal] load .dockerignore                                       0.1s
 => => transferring context: 103B                                       0.0s 
 => [internal] load build context                                       0.1s 
 => => transferring context: 406B                                       0.0s 
 => [ 1/10] FROM docker.io/library/debian:buster@sha256:233c3bbc892229  0.0s 
 => CACHED [ 2/10] RUN apt update -qq > /dev/null && apt install -qq -  0.0s 
 => [ 3/10] COPY apt.sources.list /etc/apt/sources.list                 2.1s 
 => [ 4/10] COPY apt.preferences /etc/apt/preferences.d/snapshot        0.4s
 => [ 5/10] RUN apt-get update -q &&     apt-get install -qy --allow  385.1s
 => ERROR [ 6/10] RUN useradd --uid 0 --create-home --shell /bin/bash   6.0s 
------                                                                       
 > [ 6/10] RUN useradd --uid 0 --create-home --shell /bin/bash user:         
0.957 useradd: UID 0 is not unique                                           
------                                                                       
Dockerfile:81                                                                
--------------------
  79 |     ENV WORK_DIR="${HOME_DIR}/wspace" \
  80 |         PATH="${HOME_DIR}/.local/bin:${PATH}"
  81 | >>> RUN useradd --uid $UID --create-home --shell /bin/bash ${USER}
  82 |     RUN usermod -append --groups sudo ${USER}
  83 |     RUN echo "%sudo ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
--------------------
ERROR: failed to solve: process "/bin/sh -c useradd --uid $UID --create-home --shell /bin/bash ${USER}" did not complete successfully: exit code: 4

[assorted-casuals]

attempting again on fresh install of ubuntu 24, tag 4.5.8
seems to be fixed by adding

sudo chown -R 1000:1000 "$PROJECT_ROOT"

at line #59
https://github.com/spesmilo/electrum/blob/master/contrib/build-wine/build.sh

raised a new issue
#9323