docker, shell, ruby, signal

README

1. docker build -t f440/test .
2. docker run --rm -ti f440/test
3. docker stop $(docker ps | grep f440/test | awk '{print $1}')

Dockerfile

FROM alpine

RUN apk add --no-cache ruby
RUN wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_amd64
RUN chmod +x /usr/local/bin/dumb-init

ENV TINI_VERSION v0.18.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini-static /tini
RUN chmod +x /tini

COPY ./foo.sh /tmp/foo.sh
COPY ./foo.rb /tmp/foo.rb

ENTRYPOINT ["/tini", "--"]
CMD ["/tmp/foo.sh"]

foo.rb

#!/usr/bin/env ruby

puts "I have PID #{Process.pid}"

def shut_down
  puts "\nShutting down gracefully..."
  sleep 5
end

Signal.trap("QUIT") {
  shut_down
  exit
}

Signal.trap("INT") {
  shut_down
  exit
}

# Trap `Kill `
Signal.trap("TERM") {
  shut_down
  exit
}

10.times do |i|
  puts i
  sleep 1
end

foo.sh

#!/bin/sh

echo pid: $$

exec /tmp/foo.rb # 2>&1 | tee /log/foo.log