Next Level Week 5 - Inmana

Table of Contents

• About
• Endpoints
• Setup
• Bash Commands
• Elixir Commands
• Concepts
• Libs
• Docs
• Resources

About

An inventory management backend made with Elixir and Phoenix.

Endpoints

Built-in

• GET http://localhost:4000/dashboard/home
• GET http://localhost:4000/sent_emails

WelcomeController

• GET http://localhost:4000/api?name=john&age=21

RestaurantsController

• POST http://localhost:4000/api/restaurants

SuppliesController

• GET http://localhost:4000/api/supplies/:uuid
• POST http://localhost:4000/api/supplies

Setup

1. Install asdf, an extensible version manager for node, clojure, elixir and ruby:

# Install apt-get packages
$ sudo apt install curl git

# Clone asdf
$ git clone https://github.com/asdf-vm/asdf.git ~/.asdf --branch v0.8.0

# Add it to your path
$ echo '# asdf version manager' >> ~/.bashrc
$ echo '. $HOME/.asdf/asdf.sh' >> ~/.bashrc
$ echo '. $HOME/.asdf/completions/asdf.bash' >> ~/.bashrc

• SOURCE: https://asdf-vm.com/#/core-manage-asdf

2. Install Erlang, Elixir and Phoenix:

# Install apt-get packages
$ sudo apt-get -y install build-essential autoconf m4 libncurses5-dev \
  libwxgtk3.0-gtk3-dev libgl1-mesa-dev libglu1-mesa-dev libpng-dev libssh-dev \
  unixodbc-dev xsltproc fop libxml2-utils libncurses-dev openjdk-11-jdk

# Add plugins
$ asdf plugin-add erlang
$ asdf plugin-add elixir

# Install and set Elixir
$ asdf install elixir 1.11.3
$ asdf global elixir 1.11.3

# Install and set Erlang
$ asdf install erlang 23.2
$ asdf global erlang 23.2

# Verify installation
$ erl --version
$ elixir --version

# Install Phoenix
$ mix archive.install hex phx_new 1.5.8

Postgres

Create a postgress docker container with:

$ docker run --name postgres -e POSTGRES_PASSWORD=postgres -p 5432:5432 -d postgres

Bash Commands

Phoenix

# Create phoenix app without webpacker or html views
$ mix phx.new app_name --no-webpack --no-html

# Start Phoenix dev server on http://localhost:4000
$ mix phx.server

# List all configured routes
$ mix phx.routes

# Automagically generate schema and migration
$ mix phx.gen.schema Blog.Post blog_posts title:string views:integer

Mix

# Install all dependencies
$ mix deps.get

# Compile project
$ mix compile

# Start your project as an Interactive Elixir session
$ iex -S mix

# Start your dev server with an Interactive Elixir session
$ iex -S mix phx.server

# Format all files
$ mix format

# Run a mix alias defined in ./mix.exs
$ mix example

# Run a mix task defined in ./lib/mix/tasks/example_task.ex
$ mix example_task

Ecto

# Create and migrate database
$ mix ecto.setup

# Create a migration
$ mix ecto.gen.migration migration_name

# Run pending migrations
$ mix ecto.migrate

# Drop and migrate databases
$ mix ecto.reset

# Drop databases
$ mix ecto.drop

# Create databases
$ mix ecto.create

Tests

# Run tests
$ mix test

# Run tests w/ coverage report
$ mix test --cover

Credo

# Generate linter config file
$ mix credo.gen.config

# Run linter
$ mix credo
$ mix credo --strict

Elixir Commands

Create a restaurant:

params = %{"name" => "Joe's coffee and dinner", "email" => "cup@joes.yum"}
params |> Inmana.Restaurants.Create.call()

Send expiration email:

Inmana.Supplies.ExprationNotification.send()

Task module:

list = [%{a: 5, b: 2}, %{a: 12, b: 2}, %{a: 86, b: 2}]
Task.async_stream(list, fn element -> IO.puts(element.a) end) |> Stream.run()

Atoms vs Words

:timer.tc(fn ->
  :word == :word
  :word != :word

  :dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz ==
    :dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz

  :dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz !=
    :dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz
end)

:timer.tc(fn ->
  "word" == "word"
  "word" != "word"

  "dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz" ==
    "dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz"

  "dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz" !=
    "dasdasdadasdsadasdasdasdasdqwedqsczxcaseei0i0eijqwjcxjicjz"
end)

Concepts

Concurrency vs. Parallelism

Libs

• https://github.com/phoenixframework/phoenix
• https://github.com/rrrene/credo
• https://github.com/thoughtbot/bamboo
• https://github.com/parroty/excoveralls

Docs

• https://elixir-lang.org/crash-course.html
• https://hexdocs.pm/ecto/Ecto.Changeset.html#traverse_errors/2
• https://hexdocs.pm/elixir/master/Task.html#async_stream/3
• https://hexdocs.pm/elixir/master/GenServer.html
• https://github.com/elixir-lang/elixir/releases
• https://elixirschool.com/en/lessons/basics/mix-tasks
• https://hexdocs.pm/phoenix/Mix.Tasks.Phx.Gen.Schema.html

Resources

• https://www.electronjs.org/apps/postbird
• https://www.beekeeperstudio.io/get