docker discordrb

bot.rb

require 'discordrb'

bot = Discordrb::Bot.new token: ENV["TOKEN"]
bot.message(with_text: 'Ping!') do |event|
        event.respond 'Pong!'
end

require 'thread'
Signal.trap(:TERM) do
        Thread.new { bot.stop }
end

bot.run

Dockerfile

FROM ruby AS builder
COPY Gemfile Gemfile.lock ./
RUN env DEBCONF_NOWARNINGS=yes bundle install -j "$(getconf _NPROCESSORS_ONLN)" --retry 3 \
    && rm -rf /usr/local/bundle/cache/*.gem \
    && find /usr/local/bundle/gems/ -name '*.c' -delete \
    && find /usr/local/bundle/gems/ -name '*.o' -delete
            
# app
FROM ruby:slim
RUN apt-get update \
    && apt-get upgrade -y \
    && apt-get install -y --no-install-recommends libsodium-dev \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*
COPY --from=builder /usr/local/bundle /usr/local/bundle
COPY ./app .
CMD ["ruby", "bot.rb"]