First Things First

Containerize It

Now that I have a basic Idea of what I want to build, it’s time to dive in.

The very first thing that I want to do is create a Phoenix app and throw it in a Docker container. After creating the Phoenix app by following their getting started guide, I created the following Dockerfile:

FROM elixir:latest

RUN apt-get update && \
  apt-get install -y postgresql-client

RUN mkdir /app
COPY ./remote_coach /app

RUN mix local.hex --force

RUN mix do compile

CMD ["/app/"]

As you can see, it’s very straight forward. Just copy the code, compile, and then call the entrypoint script. Now, Phoenix needs a database (usually postgresql). I could either run a local instance of postgres, or I could use a container. Since this is for development for now and I’m not too worried about data loss when a container might crash, I went with a container. For now, I am just using Docker-Compose to spin up these two containers because it was the quickest thing for now. I plan on using Kubernetes later to orchestrate these containers.

Here is the simple compose file that I am using:

version: '3'

      context: .
      PGUSER: postgres
      PGPASSWORD: postgres
      PGDATABASE: remote_coach_dev
      PGPORT: 5432
      PGHOST: db
      - "4000:4000"
      - db
    image: postgres:12.1
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
      PGDATA: /var/lib/postgresql/data/pgdata
    restart: always
      - pgdata:/var/lib/postgresql/data/pgdata


From there it’s just a simple

docker-compose build
docker-compose up

and we are up and running.


The next thing that I need is an AWS environment that I can build as I go. I plan to build this application in a way that my CI/CD pipeline can deploy code from my master branch.

For my initial test VPC, I went with a very simple 2 subnet setup in the same AZ. For now, this is all I need to just get started and play around. I have one public subnet and one private.

To create this VPC, I went directly to CloudFormation. This is to keep as much infrastructure as possible defined in code and to utilize a lot of the benefits of what AWS has for IaC.

The CloudFormation stacks that I wrote to create the VPC are too long to post here, but you could see them in my test bed project on Github

Saving Dollars

This is kind of a side note, but now that my AWS account is out of the free-tier range, I am starting to see how expensive even the smallest things can be. One of these expensive things is an AWS NAT Gateway. Just to have a NAT Gateway on 24/7 with no data costs $32/month. While that is a small price to pay for a managed gateway, I figured I could save some money since I won’t be using this 24/7 at this point.

AWS suggested a small linux instance that I manage myself for a cheaper NAT, but I thought I might be able to do something more clever for now. I decided to try using CloudFormation to spin up a new NAT whenever I needed one. It ended up being pretty straight forward:

    Type: AWS::EC2::EIP
    Type: AWS::EC2::NatGateway
          - GatewayEIP
          - AllocationId
          !Sub "${VPCStackName}-Private-Subnet"
        - Key: Name
              - ""
              - - Fn::ImportValue: !Sub "${VPCStackName}-VPCID"
                - "-NAT"

The great things about using CloudFormation for this:

  • Using Managed AWS Gateway instead of managing my own
  • Deleting various resources tied to the NAT is automatic

That’s all I have for now, the next update will be setting up my Drone CI/CD server.

532 Words

2020-02-22 07:54 -0700