Discourse_theme not interactive when running inside a Docker container

Bug
1

Hey - first, let’s say I would have preferred the ability to submit this bug report on the repo directly: GitHub - discourse/discourse_theme: CLI helper for developing Discourse themes - because I’m not sure I’m in the right place here?

discourse_theme is a Ruby tool and as I don’t want Ruby on my computer. And as I want homogeneous Ruby versions across my whole team, I did this Docker image:

# syntax = docker/dockerfile:1.10

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.4.2
ARG ALPINE_VERSION=3.20
FROM ruby:$RUBY_VERSION-alpine${ALPINE_VERSION}

# Install packages
RUN --mount=type=cache,id=dev-apk-cache,sharing=locked,target=/var/cache/apk \
  --mount=type=cache,id=dev-apk-lib,sharing=locked,target=/var/lib/apk \
  apk add \
  ca-certificates \
  bash \
  tzdata \
  xz-libs \
  gcompat \
  zstd-libs \
  libpq

RUN gem install discourse_theme

ENTRYPOINT ["discourse_theme"]

I can run it like this:

# BUILD first
docker build -t discourse_theme:latest .

# RUN WATCH
docker run -i -t --rm -v $(pwd):/root -w /root discourse_theme:latest watch .

The issue I want to report here is about the CLI interactivity.

There is no keyboard interactivity while in Docker.

I see this when running:

image
image1550×176 28.9 KB

If I tap an arrow key the help message goes away, but the green “selected” option never moves:

A dark terminal window displays a command being executed to run a Docker container with various parameters, alongside log messages indicating progress in setting up a Discourse theme. (Captioned by AI)
A dark terminal window displays a command being executed to run a Docker container with various parameters, alongside log messages indicating progress in setting up a Discourse theme. (Captioned by AI)1550×164 24.6 KB

So I think this is a bug in the Gem. It detected a keypress, but it did not move the selection. I tested a lot of keypress.

Another test I did was running bash in the image, and launching discourse_theme from there, but it’s the same issue.

$ docker run -it --rm -v $(pwd):/root -w /root --entrypoint /bin/bash discourse_theme:latest
9f5736f3265e:~# discourse_theme watch .

Is that normal behavior for Ruby CLI tools or is there a bug? Thanks