ActionView::Template::Error (The asset "tailwind.css" is not present in the asset pipeline.

Hi all, I am trying to deploy my rails project with flyctl deploy and it deploys fine, but the logs show

ActionView::Template::Error (The asset “tailwind.css” is not present in the asset pipeline.

I can run fly ssh console and find that tailwind.css file in app/assets/builds just fine and I cannot seem to find the solution to this.

Dockerfile:
Here is my Dockerfile

# syntax = docker/dockerfile:experimental

# Dockerfile used to build a deployable image for a Rails application.
# Adjust as required.
#
# Common adjustments you may need to make over time:
#  * Modify version numbers for Ruby, Bundler, and other products.
#  * Add library packages needed at build time for your gems, node modules.
#  * Add deployment packages needed by your application
#  * Add (often fake) secrets needed to compile your assets

#######################################################################

# Learn more about the chosen Ruby stack, Fullstaq Ruby, here:
#   https://github.com/evilmartians/fullstaq-ruby-docker.
#
# We recommend using the highest patch level for better security and
# performance.

ARG RUBY_VERSION=2.7.2
ARG VARIANT=jemalloc-slim
FROM quay.io/evl.ms/fullstaq-ruby:${RUBY_VERSION}-${VARIANT} as base

LABEL fly_launch_runtime="rails"

ARG NODE_VERSION=16.15.1
ARG YARN_VERSION=1.22.17
ARG BUNDLER_VERSION=2.1.4

ARG RAILS_ENV=production
ENV RAILS_ENV=${RAILS_ENV}

ENV RAILS_SERVE_STATIC_FILES true
ENV RAILS_LOG_TO_STDOUT true

ARG BUNDLE_WITHOUT=development:test
ARG BUNDLE_PATH=vendor/bundle
ENV BUNDLE_PATH ${BUNDLE_PATH}
ENV BUNDLE_WITHOUT ${BUNDLE_WITHOUT}

RUN mkdir /app
WORKDIR /app
RUN mkdir -p tmp/pids

RUN curl https://get.volta.sh | bash
ENV VOLTA_HOME /root/.volta
ENV PATH $VOLTA_HOME/bin:/usr/local/bin:$PATH
RUN volta install node@${NODE_VERSION} yarn@${YARN_VERSION} && \
    gem update --system --no-document && \
    gem install -N bundler -v ${BUNDLER_VERSION}

#######################################################################

# install packages only needed at build time

FROM base as build_deps

ARG BUILD_PACKAGES="git build-essential libpq-dev wget vim curl gzip xz-utils libsqlite3-dev"
ENV BUILD_PACKAGES ${BUILD_PACKAGES}

RUN --mount=type=cache,id=dev-apt-cache,sharing=locked,target=/var/cache/apt \
    --mount=type=cache,id=dev-apt-lib,sharing=locked,target=/var/lib/apt \
    apt-get update -qq && \
    apt-get install --no-install-recommends -y ${BUILD_PACKAGES} \
    && rm -rf /var/lib/apt/lists /var/cache/apt/archives

#######################################################################

# install gems

FROM build_deps as gems

COPY Gemfile* ./
RUN bundle install &&  rm -rf vendor/bundle/ruby/*/cache

#######################################################################

# install node modules

FROM build_deps as node_modules

COPY package*json ./
COPY yarn.* ./
RUN yarn install

#######################################################################

# install deployment packages

FROM base

ARG DEPLOY_PACKAGES="postgresql-client file vim curl gzip libsqlite3-0"
ENV DEPLOY_PACKAGES=${DEPLOY_PACKAGES}

RUN --mount=type=cache,id=prod-apt-cache,sharing=locked,target=/var/cache/apt \
    --mount=type=cache,id=prod-apt-lib,sharing=locked,target=/var/lib/apt \
    apt-get update -qq && \
    apt-get install --no-install-recommends -y \
    ${DEPLOY_PACKAGES} \
    && rm -rf /var/lib/apt/lists /var/cache/apt/archives

# copy installed gems
COPY --from=gems /app /app
COPY --from=gems /usr/lib/fullstaq-ruby/versions /usr/lib/fullstaq-ruby/versions
COPY --from=gems /usr/local/bundle /usr/local/bundle

# copy installed node modules
COPY --from=node_modules /app/node_modules /app/node_modules

#######################################################################

# Deploy your application
COPY . .

# Adjust binstubs to run on Linux and set current working directory
RUN chmod +x /app/bin/* && \
    sed -i 's/ruby.exe/ruby/' /app/bin/* && \
    sed -i '/^#!/aDir.chdir File.expand_path("..", __dir__)' /app/bin/*

# The following enable assets to precompile on the build server.  Adjust
# as necessary.  If no combination works for you, see:
# https://fly.io/docs/rails/getting-started/existing/#access-to-environment-variables-at-build-time
ENV SECRET_KEY_BASE 1
# ENV AWS_ACCESS_KEY_ID=1
# ENV AWS_SECRET_ACCESS_KEY=1

# Run build task defined in lib/tasks/fly.rake
ARG BUILD_COMMAND="bin/rails fly:build"
RUN ${BUILD_COMMAND}

# Default server start instructions.  Generally Overridden by fly.toml.
ENV PORT 8080
ARG SERVER_COMMAND="bin/rails fly:server"
ENV SERVER_COMMAND ${SERVER_COMMAND}
CMD ${SERVER_COMMAND}

fly.toml:

# fly.toml file generated for workaholic on 2022-11-08T17:20:08-05:00

app = "workaholic"
kill_signal = "SIGINT"
kill_timeout = 5
processes = []

[build]
  [build.args]
    BUILD_COMMAND = "bin/rails fly:build"
    SERVER_COMMAND = "bin/rails fly:server"

[deploy]
  release_command = "bin/rails fly:release"

[env]
  PORT = "8080"

[experimental]
  allowed_public_ports = []
  auto_rollback = true

[[services]]
  http_checks = []
  internal_port = 8080
  processes = ["app"]
  protocol = "tcp"
  script_checks = []
  [services.concurrency]
    hard_limit = 25
    soft_limit = 20
    type = "connections"

  [[services.ports]]
    force_https = true
    handlers = ["http"]
    port = 80

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 443

  [[services.tcp_checks]]
    grace_period = "1s"
    interval = "15s"
    restart_limit = 0
    timeout = "2s"

[[statics]]
  guest_path = "/app/public"
  url_prefix = "/"

.dockerignore:

.git
tmp
!tmp/pids
log
public/assets
public/packs
.bundle

db/*.sqlite3
db/*.sqlite3-*

storage
config/master.key
config/credentials/*.key

node_modules

Gemfile:

source "https://rubygems.org"
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby "2.7.2"

# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
gem "rails", "~> 7.0.3", ">= 7.0.3.1"

# The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
gem "sprockets-rails"

# Use postgresql as the database for Active Record
gem "pg", "~> 1.1"

# Use the Puma web server [https://github.com/puma/puma]
gem "puma", "~> 5.0"

# Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails]
gem "importmap-rails"

# Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev]
gem "turbo-rails"

# Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev]
gem "stimulus-rails"

# Use Tailwind CSS [https://github.com/rails/tailwindcss-rails]
gem "tailwindcss-rails"

# Build JSON APIs with ease [https://github.com/rails/jbuilder]
gem "jbuilder"

# Use Redis adapter to run Action Cable in production
# gem "redis", "~> 4.0"

# Use Kredis to get higher-level data types in Redis [https://github.com/rails/kredis]
# gem "kredis"

# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
# gem "bcrypt", "~> 3.1.7"

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem "tzinfo-data", platforms: %i[ mingw mswin x64_mingw jruby ]

# Reduces boot times through caching; required in config/boot.rb
gem "bootsnap", require: false

# Use Sass to process CSS
# gem "sassc-rails"

# Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
# gem "image_processing", "~> 1.2"

gem 'devise'

gem "heroicon"

group :development, :test do
  # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
  gem "debug", platforms: %i[ mri mingw x64_mingw ]
end

group :development do
  # Use console on exceptions pages [https://github.com/rails/web-console]
  gem "web-console"
  gem "hotwire-livereload"

  # Add speed badges [https://github.com/MiniProfiler/rack-mini-profiler]
  # gem "rack-mini-profiler"

  # Speed up commands on slow machines / big apps [https://github.com/rails/spring]
  # gem "spring"
end

group :test do
  # Use system testing [https://guides.rubyonrails.org/testing.html#system-testing]
  gem "capybara"
  gem "selenium-webdriver"
  gem "webdrivers"
end

gem "acts_as_list", "~> 1.0"

application.rb

require_relative 'boot'

require 'rails/all'

# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)

module Workaholic
  class Application < Rails::Application
    # Initialize configuration defaults for originally generated Rails version.
    config.load_defaults 7.0

    # Configuration for the application, engines, and railties goes here.
    #
    # These settings can be overridden in specific environments using the files
    # in config/environments, which are processed later.
    #
    # config.time_zone = "Central Time (US & Canada)"
    # config.eager_load_paths << Rails.root.join("extras")
  end
end

fly.rake

# commands used to deploy a Rails application
namespace :fly do
  # BUILD step:
  #  - changes to the filesystem made here DO get deployed
  #  - NO access to secrets, volumes, databases
  #  - Failures here prevent deployment
  task :build => 'assets:precompile'

  # RELEASE step:
  #  - changes to the filesystem made here are DISCARDED
  #  - full access to secrets, databases
  #  - failures here prevent deployment
  task :release => 'db:migrate'

  # SERVER step:
  #  - changes to the filesystem made here are deployed
  #  - full access to secrets, databases
  #  - failures here result in VM being stated, shutdown, and rolled back
  #    to last successful deploy (if any).
  task :server => :swapfile do
    sh 'bin/rails server'
  end

  # optional SWAPFILE task:
  #  - adjust fallocate size as needed
  #  - performance critical applications should scale memory to the
  #    point where swap is rarely used.  'fly scale help' for details.
  #  - disable by removing dependency on the :server task, thus:
  #        task :server do
  task :swapfile do
    sh 'fallocate -l 512M /swapfile'
    sh 'chmod 0600 /swapfile'
    sh 'mkswap /swapfile'
    sh 'echo 10 > /proc/sys/vm/swappiness'
    sh 'swapon /swapfile'
  end
end

That’s the source file. Can you verify that you have a compiled version? Here’s what I see on my app:

find . -name tailw*.css
./public/assets/tailwind-5146aee928b28afaac2c45702cb895da9e08ffa516864007783ebac005938e39.css
./app/assets/builds/tailwind.css

The public:assets directory should be set up by the assets:precompile step. This looks to be set up correctly in your Dockerfile and lib/tasks/fly.rake.