When I run my app in productions tailwind doenst build assets

[rodrigoazv]

#When I run my app in production, Tailwind doesn't build the assets.

Locally, when I run rails assets:precompile, I receive this output:

                                                                                                                                                         +   09:46:14
❯ SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile --trace
** Invoke assets:precompile (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke tailwindcss:build (first_time)
** Invoke environment
** Execute tailwindcss:build
≈ tailwindcss v4.0.17

Done in 55ms
** Execute assets:precompile
Warning: You are precompiling assets in development. Rails will not serve any changed assets until you delete public/assets/.manifest.json

My app creates the Tailwind build files correctly.

But when my Dockerfile runs in production mode, the Tailwind precompiled assets don't build with the rest of the app, and my output doesn't include any Tailwind files.

When I run rails server locally, works well, but in production doesnt work, don't apply any style.

I'm using rails 8, and v4 of all tailwind dependencies.

Has some config missing for production mode? I just create rails new --css=tailwind for test

[patriciomacadden]

Hi @rodrigoazv , can you share more details? I guess you're using the default Dockerfile generated by rails, but if you're not, can you share it?

I've tried with the default Dockerfile generated by rails and worked fine:

#15 [build 6/6] RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile --trace
#15 0.378 ** Invoke assets:precompile (first_time)
#15 0.378 ** Invoke environment (first_time)
#15 0.378 ** Execute environment
#15 0.451 ** Invoke tailwindcss:build (first_time)
#15 0.451 ** Invoke environment
#15 0.451 ** Execute tailwindcss:build
#15 0.582 ≈ tailwindcss v4.0.14
#15 0.582
#15 0.582 Done in 42ms
#15 0.587 ** Execute assets:precompile
#15 0.609 Writing tailwind-c2faee52.css
#15 0.609 Writing logo-1d3a52a0.svg
#15 0.609 Writing application-8b441ae0.css
#15 0.609 Writing controllers/hello_controller-708796bd.js
#15 0.609 Writing controllers/index-ee64e1f1.js
#15 0.609 Writing controllers/application-5df0f280.js
#15 0.609 Writing application-bfcdf840.js
#15 0.609 Writing stimulus-use-674d7652.js
#15 0.609 Writing @stimulus-components--dropdown-36bcc32d.js
#15 0.609 Writing stimulus.min-2395e199.js.map
#15 0.609 Writing stimulus.min-4b1e420e.js
#15 0.609 Writing stimulus-loading-1fc53fe7.js
#15 0.609 Writing stimulus-autoloader-9d447422.js
#15 0.609 Writing stimulus-importmap-autoloader-64cc03e1.js
#15 0.609 Writing stimulus-d59b3b7f.js
#15 0.609 Writing turbo.min-02fd5b81.js.map
#15 0.609 Writing turbo-765c2e69.js
#15 0.609 Writing turbo.min-1262d735.js
#15 0.609 Writing trix-4b540cb5.js
#15 0.609 Writing actiontext-a4ee937e.js
#15 0.609 Writing actiontext.esm-f1c04d34.js
#15 0.609 Writing trix-65afdb1d.css
#15 0.609 Writing actioncable.esm-e0ec9819.js
#15 0.609 Writing actioncable-ac25813f.js
#15 0.609 Writing action_cable-5212cfee.js
#15 0.609 Writing activestorage.esm-f2909226.js
#15 0.609 Writing activestorage-32201f68.js
#15 0.609 Writing rails-ujs-20eaf715.js
#15 0.609 Writing rails-ujs.esm-e925103b.js
#15 DONE 0.6s

If you look closely you can see tailwind cli being run. There's been some issues with it lately, see #509 . But!! I'm not sure if it's the same problem.

Can you run docker run -it <yourimage> bash and see if you can get tailwind cli running, or if you get any error?

[rodrigoazv]

Here is my dockerfile, should I change something? Cli really runs but doenst create any tailwind file.

# syntax=docker/dockerfile:1
# check=error=true

# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
# docker build -t zaplist .
# docker run -d -p 80:80 -e RAILS_MASTER_KEY=<value from config/master.key> --name zaplist zaplist

# For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
ARG RUBY_VERSION=3.3.6
FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

# Rails app lives here
WORKDIR /rails

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libjemalloc2 libvips postgresql-client libpq-dev sqlite3 libpq5 && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Set production environment
ENV RAILS_ENV="production" \
    BUNDLE_DEPLOYMENT="1" \
    BUNDLE_PATH="/usr/local/bundle" \
    BUNDLE_WITHOUT="development"

# Throw-away build stage to reduce size of final image
FROM base AS build

# Install packages needed to build gems
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential git libpq-dev pkg-config libpq5 && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Install application gems
COPY Gemfile Gemfile.lock ./
RUN bundle install && \
    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
    bundle exec bootsnap precompile --gemfile

# Copy application code
COPY . .

# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/

# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile --trace

# Final stage for app image
FROM base

# Copy built artifacts: gems, application
COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
COPY --from=build /rails /rails

# Run and own only the runtime files as a non-root user for security
RUN groupadd --system --gid 1000 rails && \
    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash && \
    chown -R rails:rails db log storage tmp
USER 1000:1000

# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

# Start server via Thruster by default, this can be overwritten at runtime
EXPOSE 80
CMD ["./bin/thrust", "./bin/rails", "server"]

[patriciomacadden]

Dockerfile looks fine, have you checked #509 ? Have you run rails tailwindcss:build inside the container? can you see app/assets/builds/tailwind.css inside the container?

[rodrigoazv]

I found something.

When I try to run it directly in my container on the VM, I get an error. I will close this issue and try to fix it first.

But if I have a permission error, shouldn't my build generate an error during deployment?

[rodrigoazv]

@patriciomacadden When I build the image locally, docker create correctly

But when I build and deploy with kamal 2 in my VM, doesn't work, don't create tailwind file in build.

Do you know something in deploy.yml to solve this?

[patriciomacadden]

Hi @rodrigoazv , good thing you got it working locally! That's progress.

Unfortunately I haven't used kamal yet so I'm not sure what might be going on... 😢

[rodrigoazv]

I see think we has problems between Kamal and Docker, but after downgrading to version 3.3.1, it worked fine!

I’ll look into it more in the future. My app doesn’t rely heavily on the frontend, but thanks, @patriciomacadden, for your attention!

[flavorjones]

Possibly relevant thread: #499 (comment)

[rodrigoazv]

Thanks @flavorjones , that’s probably it — I’ll try it out in upcoming projects.

As I mentioned before, this project isn’t front-end based; I only used Tailwind to define a few things.

But thank you very much!

[flavorjones]

Seems like this is due to tailwindlabs/tailwindcss#17728

[flavorjones]

Just a note that the underlying cause seems to have been discovered, and there are some workarounds you can try.

• underlying cause: Floating point values are truncated when run on M1 with Rosetta x86_64 emulation (via Docker) oven-sh/bun#19677
• explanation and workarounds: Styles aren't generated when building a Docker image for ARM64 on a 2019 Intel MacBook Pro tailwindlabs/tailwindcss#17728 (comment)