Cashier 🛒

Main module Cashier.

This is a minimal elixir application that implements a shopping kart.

Installation 🚀

So that the teams local environments can be as similar as possible and all of the same versions of each package are used, I have used asdf. If you don't have it already installed you can just run make asdf and make install.

By doing this you will be running:

git clone https://github.com/asdf-vm/asdf.git ~/.asdf --branch v0.6.2

asdf plugin-add erlang https://github.com/asdf-vm/asdf-erlang.git
asdf plugin-add elixir https://github.com/asdf-vm/asdf-elixir.git
asdf plugin-add terraform https://github.com/Banno/asdf-hashicorp.git

And then ☕️

asdf install

These bash commands have been redirected to /dev/null, so don't worry if you have previously installed any of the packages.

If you don't have asdf in your dot-files, add it like this:

echo -e '\n. $HOME/.asdf/asdf.sh' >> ~/.bashrc

If you use zsh, you should add it to your .zshrc file.

Hooks ⚓️

To ensure a fast and secure development and to avoid mistakes, using hooks is encouraged. If you want to do so, you can install them by running make hooks. This will install pre-commit, which is a python package; so you will need to have python already installed.

Documentation 🗃

Ex doc has been added as a depenency in order to generate documentation for the codebase. If you fancy reviewing the different modules and their function run make docs.

Continuous Integration 🔁

Elixir CI github action has been set up. It runs the following tasks.

- name: Check Formatting
  run: mix format --check-formatted

- name: Run Tests
  run: mix test

- name: Check Typespec
  run: mix dialyzer --halt-exit-status

- name: Run Coveralls
  run: mix coveralls.github

Here is the action yaml.

Code coverage has also been set up with coveralls.

ECR pipeline 🏎

This pipeline builds a multi stage docker image. The builder stage inherits from elixir:1.9.4 which is the latest version on 2020-01. This stage generates the docs. Then this docs are copied into an apache2 container into the default virtual host folder.

  # Builder stage
  FROM elixir:1.9.4 as builder

  RUN mix local.hex --force \\
   && mix local.rebar --force

  RUN mkdir -p /cashier
  WORKDIR /cashier

  COPY . .

  RUN mix deps.get && \\
      mix deps.compile && \\
      mix docs

  # Default stage
  FROM httpd:2.4
  COPY --from=builder /cashier/doc /usr/local/apache2/htdocs/

  CMD [ "httpd-foreground" ]

if you want to run the image locally, you need to build it first:

  docker build . -t cashier-docs
  docker run -p 8080:80 cashier-docs

One the github actio has built the image then it is pushed to a private aws docker registy. You can check the steps ecr.

Terraform (CD, ECR, ECS) 🏗

The registry has been built with terraform. After speaking with Dan I immediatelly wanted to do something with ECS. So, after all cashier requirements were satisfied, I Jumped onto terraform and AWS 🤙.

Al resources had been declared here.

There is already a working cahier-docs here

If you want play with terraform export the environment variables that I sent in the email like this:

  export AWS_ACCESS_KEY_ID=XXXXXXXXXXXXXXXXXXXX
  export AWS_SECRET_ACCESS_KEY=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Once you have this set up you can destroy the ECS service if you want. To do so you need to specify the resource target because the registry has been declared with prevent_destroy as you can see here:

  lifecycle {
    prevent_destroy = true
  }

Init 🤯

Asdf plugin for terraform should be already installed from previous make install.

  terraform init

  terraform destroy -target=aws_ecs_cluster.sense_eight
  terraform destroy -target=aws_security_group.docs_sg

This will destroy the service and wont be accessible for the time being. Whenever you run apply or destroy you need to confirm the plan by writing yes.

Once we have everything destroyed but the ECRegistry, we can run apply again. We need to do this in two stages in order to query the public ip or dns.

  terraform apply --var 'show_ip=true'
  terraform refresh --var 'show_ip=true'

The state is remotely stored in s3, so even that *.tfstate is not under version control, you should be able to access the infrastructure state 🙆🏻‍♂️.

gilacost/cashier