Sidekiq image (crontab + whenever)

docker-entrypoint.sh

#!/bin/sh

set -e

service cron start

exec "$@"

Dockerfile

FROM ruby:2.5.7

RUN apt-get update && apt-get install -y cron
RUN apt-get install -y nano

COPY Gemfile* /usr/src/app/

WORKDIR /usr/src/app

ENV BUNDLE_PATH /gems
# Adding an editor for crontab -e (visualizing crontab)
ENV EDITOR nano

RUN gem update bundler

RUN bundle install

COPY . /usr/src/app

RUN chmod +x ./docker-entrypoint.sh

# Using here because my schedule is empty. Can be ignored
RUN bundle exec wheneverize

RUN bundle exec whenever -w

ENTRYPOINT [ "./docker-entrypoint.sh" ]

# latest two configs are not necessary.
# You can just use CMD [ "bundle", "exec", "sidekiq"]. If there are any specific params
# to pass to sidekiq, you can do so like below
CMD [ "bundle", "exec", "sidekiq", "-r", "./config/boot.rb" ]