Dockerfile

# Sets the Docker image that will be used as a base.
FROM trenpixster/elixir:1.3.0

# Compiles app
RUN mkdir /app
WORKDIR /app

ENV MIX_ENV prod

# Injects AWS env variables explained below
ENV HOST_VARS inject_here

# Installs all the Elixir Dependencies
ADD mix.* ./
RUN mix local.rebar
RUN mix local.hex --force
RUN mix deps.get

# Installs the app
ADD . .
RUN prod mix compile

# Exposes this port from the docker container to the host machine
EXPOSE 4000

# Migrate the database 
CMD mix ecto.migrate

# Starts the phoenix server
CMD mix phoenix.server