How do I run `PORT=1234 npx y-websocket` in a multiprocess?

Questions / Help
,
15

@rubys @halfer
I was able to move it safely. Thank you very much.

I will describe the code below and hope it will be helpful to others in the same situation.

  • supervisord.conf
[supervisord]
logfile=/dev/stdout 
logfile_maxbytes=0  
loglevel=info
pidfile=/tmp/supervisord.pid
nodaemon=true

[program:rails]
command=./bin/rails server

[program:ws]
command=bash -c "HOST=0.0.0.0 PORT=1234 npx y-websocket"
  • fly.toml
# fly.toml app configuration file generated for bookrin on 2025-03-15T23:24:38+09:00
#
# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
#

app = 'bookrin'
primary_region = 'nrt'
console_command = '/rails/bin/rails console'

[deploy]
  release_command = './bin/rails db:prepare'

[http_service]
  internal_port = 3000
  force_https = true
  auto_stop_machines = "off"
  auto_start_machines = true
  min_machines_running = 0

  [http_service.concurrency]
    type = "requests"
    soft_limit = 200
    hard_limit = 250

[[services]]
  internal_port = 1234
  protocol = "tcp"

  [[services.ports]]
    port = 1234
    handlers = ["tls"]

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

[[statics]]
  guest_path = '/rails/public'
  url_prefix = '/'
  • Docker
# syntax=docker/dockerfile:1
# check=error=true

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
ARG RUBY_VERSION=3.4.2
FROM ruby:$RUBY_VERSION-slim AS base

LABEL fly_launch_runtime="rails"

# Rails app lives here
WORKDIR /rails

# Update gems and bundler
RUN gem update --system --no-document && \
    gem install -N bundler

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libjemalloc2 postgresql-client supervisor nodejs npm && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

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


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

# Install packages needed to build gems and node modules
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential git libpq-dev libyaml-dev node-gyp pkg-config python-is-python3 && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Install Node.js
ARG NODE_VERSION=20.12.2
ENV PATH=/usr/local/node/bin:$PATH
RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz -C /tmp/ && \
    /tmp/node-build-master/bin/node-build "${NODE_VERSION}" /usr/local/node && \
    rm -rf /tmp/node-build-master

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

# Install node modules
COPY package.json package-lock.json ./
RUN npm install

# Copy application code
COPY . .

# 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
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf

# 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 1000:1000 db log tmp

CMD ["/usr/bin/supervisord"]
  • websocket instance(in JS)
const wsUrl = railsEnv === 'production' ? 'wss://bookrin.fly.dev:1234/' : 'ws://localhost:5678';