instruction: Create a Dockerfile for Nginx with production best practices
output: ```dockerfile
  from
  the recipient container back to the source (for example, MYSQL_PORT_3306_TCP).For more information about EXPOSE, see
  Dockerfile reference for the EXPOSE instruction.ENVTo make new software easier to run, you can use ENV to update the
  PATH environment variable for the software your container installs. For
  example, ENV PATH=/usr/local/nginx/bin:$PATH ensures that CMD ["nginx"]
  just works.The ENV instruction is also useful for providing the required environment
  variables specific to services you want to containerize, such as Postgresâs
  PGDATA.Lastly, ENV can also be used to set commonly used version numbers so that
  version bumps are easier to maintain, as seen in the following example:
  
  ENV PG_MAJOR=9.3
  ENV PG_VERSION=9.3.4
  RUN curl -SL https://example.com/postgres-$PG_VERSION.tar.xz | tar -xJC /usr/src/postgres && â¦
  ENV PATH=/usr/local/postgres-$PG_MAJOR/bin:$PATHSimilar to having constant variables in a program, as opposed to hard-coding
  values, this approach lets you change a single ENV instruction to
  automatically bump the version of the software in your container.Each ENV line creates a new intermediate layer, just like RUN commands. This
  means that even if you unset the environment variable in a future layer, it
  still persists in this layer and its value can be dumped. You can test this by
  creating a Dockerfile like the following, and then building it.
  
  # syntax=docker/dockerfile:1
  ```