Rails 8 I always get a bad gateway 502 when the machine starts

It is working, after removing thruster and changing the http port. For those using rails 8 who are having the same problem, check my config below

fly.toml

app = 'your-app-name-here'
primary_region = 'gru'
console_command = '/rails/bin/rails console'

[build]

[env]
  DATABASE_URL = 'sqlite3:///data/production.sqlite3'
  HTTP_PORT = '3000'

[[mounts]]
  source = 'data'
  destination = '/data'

[http_service]
  internal_port = 3000
  force_https = true
  auto_stop_machines = 'stop'
  auto_start_machines = true
  min_machines_running = 0
  processes = ['app']

[checks]
  [checks.status]
    port = 3000
    type = 'http'
    interval = '10s'
    timeout = '3s'
    grace_period = '15s'
    method = 'GET'
    path = '/up'
    protocol = 'http'
    tls_skip_verify = false

    [checks.status.headers]
      X-Forwarded-Proto = 'https'

[[vm]]
  memory = '512mb'
  cpu_kind = 'shared'
  cpus = 1

Dockerfile

ARG RUBY_VERSION=3.3.0
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 sqlite3 && \
    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 pkg-config && \
    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




# 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"]

EXPOSE 80
EXPOSE 3000

CMD ["./bin/rails", "server"]

Thanks for the help!

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