FROM node:16.13.1-alpine RUN apk update && apk add dnsmasq WORKDIR /usr/app ENV PATH="/usr/app/bin:${PATH}" # schedule critical checks to run every 5 minutes (any failures will disable server) RUN echo '*/5 * * * * /usr/app/bin/cli run critical > /dev/stdout' >> /etc/crontabs/root # schedule extended checks to run on every hour (optional checks, report only) RUN echo '0 * * * * /usr/app/bin/cli run extended > /dev/stdout' >> /etc/crontabs/root COPY package.json yarn.lock ./ RUN yarn --frozen-lockfile COPY src src COPY cli cli COPY bin bin EXPOSE 3100 ENV NODE_ENV production # 1. start dnsmasq in the background with: # - alias PORTAL_DOMAIN with current server ip so it overrides potential load balancer request # - default docker nameserver 127.0.0.11 for any other request # 2. replace docker nameserver with dnsmasq nameserver in /etc/resolv.conf # 3. start crond in the background to schedule periodic health checks # 4. start the health-check api service CMD [ "sh", "-c", \ "serverip=$(node src/whatismyip.js) ; \ dnsmasq --no-resolv --log-facility=/var/log/dnsmasq.log --address=/$PORTAL_DOMAIN/$serverip --server=127.0.0.11 ; \ echo \"$(sed 's/127.0.0.11/127.0.0.1/' /etc/resolv.conf)\" > /etc/resolv.conf ; \ crond ; \ node src/index.js" \ ]