Example Dockerfile to use as base

• Multistage, state one "FROM base as builder" builds code/libs
  • Second stage starts over "FROM base" and copies "--from=builder" files from first container.

• example Dockerfile

  FROM python:3.7-alpine as base
  FROM base as builder
  RUN mkdir /install
  WORKDIR /install
  COPY requirements.txt /requirements.txt
  RUN pip install --install-option="--prefix=/install" -r /requirements.txt
  
  
  FROM base
  COPY --from=builder /install /usr/local
  COPY src /app
  COPY README.md /
  WORKDIR /app
  #With entrypoint can pass commandline arguments
  ENTRYPOINT ["python" , "send-mail.py"]

• Dockerfile for serverless aws lambda build

  #PES 2020
  FROM debian:buster
  
  # Install Python3 with pip and devel
  # Install GCC, Make and MySQL-devel, NodeJS, Nano, findutils, and libyaml for parsing .yml (serverless) via Python
  # Clean-up after ourselves
  #RUN curl --silent --location https://rpm.nodesource.com/setup_8.x | bash - && \
  RUN apt-get update &&\ 
      apt-get upgrade -y &&\
      apt-get install -y \
          apt-utils \
          python3-pip python3-dev \
          python3-yaml \
          make \
          nodejs npm \
          vim findutils 
          git && \
       apt-get clean all && rm -rf /var/cache/apt
  
  # Install the serverless framework globally
  RUN npm install -g serverless
  
  # Install/upgrade pip, awscli, mysqlclient for both Python 2.7 and Python 3.6
  RUN ls -la /usr/local/bin
  RUN find / -iname "pip*"
  
  RUN pip-3 install --no-cache-dir --upgrade pip awscli mysqlclient pyyaml
    
  ENTRYPOINT ["/bin/bash"] 
  # "-c"]

• Last stage in dockerfile that creates nginx container with selfsigned cert

  #########################################################
  FROM docker.io/debian:bullseye-slim
  RUN apt-get update && apt-get install -y nginx openssl jo &&\
      rm -rf /var/lib/apt/lists/* &&\
      openssl req -x509 -nodes -days 3650 \
      -subj "/C=NZ/ST=Auckland/O=SelfSigned/OU=private/CN=net.nz" \
      -addext "subjectAltName=DNS:selfsigned.net.nz" \
      -newkey rsa:2048 \
      -keyout /etc/ssl/private/nginx-selfsigned.key \
      -out /etc/ssl/certs/nginx-selfsigned.crt
  
  # link nginx logs to stdout create basic nginx config
  RUN ln -sf /dev/stdout /var/log/nginx/access.log &&\
      ln -sf /dev/stderr /var/log/nginx/error.log &&\
      printf '#Generated in Dockerfile;\n\
      charset utf-8;\n\
      server {\n\
      listen 80;\n\
      server_name _;\n\
      return 301 https://$host$request_uri;\n\
      root /var/www/html;\n\
      }\n\
      server {\n\
      listen 443 ssl;\n\
      server_name _;\n\
      root /var/www/html;\n\
      index index.html index.htm;\n\
      ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;\n\
      ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;\n\
      # ssl_password_file /usr/nginx/ssl.pass;\n\
      }\n' > /etc/nginx/sites-enabled/default
  
  # add static website to final container
  WORKDIR /var/www/html
  COPY --from=builder /usr/app/build /var/www/html
  EXPOSE 80
  EXPOSE 443
  COPY Dockerentrypoint.sh /Dockerentrypoint.sh
  ENTRYPOINT [ "/Dockerentrypoint.sh" ]
  CMD [ "nginx", "-g", "daemon off;" ]

• Dockerentrypoint.sh that converts env vars into config file

  # Container startups script.
  # Allow for runtime configuration through env vars.
  # https://12factor.net/build-release-run
  set -e
  echo "# Start container with $0  PWD=${PWD}"
  echo "#"
  
  echo "# cat .version.txt"
  cat .version.txt
  echo "#"
  
  prefix="REACT_APP_"
  echo "# Add env vars ${prefix}* to ''env.js'' at webserver root"
  echo "export default () => (`jo -p \`env | grep ${prefix} | sed -e 's/[[:blank:]]/{_!!_}/g'\` end=1`)" | sed -e 's/{_!!_}/ /g' | tee env.js
  echo "#"
  
  echo "# Starting docker cmd \$@=$@ ..."
  exec "$@"