Phoenix - Getting Started

27 Jul 2017

install Phoenix
create new project
set up Git repo
set up database
- with Docker
- without Docker
start app
customize app
- add useful packages
- generate schemas

install Phoenix

install or update Hex package manager:

$ mix local.hex

install latest Phoenix version:

$ mix archive.install hex phx_new 1.4.1

create new project

https://hexdocs.pm/phoenix/up_and_running.html

$ mix phx.new billing

for API-only projects (see mix help phx.new):

$ mix phx.new billing --no-webpack --no-html

set up Git repo

https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/

$ cd billing
$ git init
$ git add -A .
$ git commit -m 'initial commit'
$ get remote add origin <REMOTE_REPO_URL>
$ git push

set up database

with Docker

# docker-compose.yml

version: '2'
services:
  db:
    image: postgres:11.1
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    ports:
      - 5434:5432

https://hub.docker.com/_/postgres?tab=description

POSTGRES_USER

This variable will create the specified user with superuser power and a database with the same name.

it’s possible not to specify POSTGRES_USER and POSTGRES_PASSWORD variables in docker-compose.yml at all because they default to postgres but IMO it’s still better to make it explicit.

# config/dev.secret.exs

config :eva, Eva.Repo,
  username: "postgres",
  password: "postgres",
  database: "eva_dev",
  hostname: "localhost",
  port: 5434,
  pool_size: 10

# config/test.secret.exs

config :eva, Eva.Repo,
  username: "postgres",
  password: "postgres",
  database: "eva_test",
  hostname: "localhost",
  port: 5434,
  pool: Ecto.Adapters.SQL.Sandbox

$ docker-compose up
$ mix ecto.create && MIX_ENV=test mix ecto.create

NOTE: don’t use postgres user in production - create a separate application user (this is how it’s done in my Ansible tasks):

# config/prod.secret.exs

config :eva, Eva.Repo,
  username: "eva_prod",
  password: "password",
  database: "eva_prod",
  pool_size: 15

without Docker

https://stackoverflow.com/a/15309551/3632318

macOS PostgreSQL installation doesn’t create postgres user by default (even though postgres database is created):

$ psql -d postgres
...
postgres=# \du
                                  List of roles
Role name |                         Attributes                         | Member of
-----------+------------------------------------------------------------+-----------
tap       | Superuser, Create role, Create DB, Replication, Bypass RLS | {}

create him manually:

$ psql -d postgres
...
postgres=# CREATE USER postgres WITH SUPERUSER PASSWORD 'postgres';
CREATE ROLE

postgres user is used by default in generated config/dev.exs and config/test.exs files so just leave these defaults.

config/dev.exs (for example):

config :billing, Billing.Repo,
  adapter: Ecto.Adapters.Postgres,
  username: "postgres",
  password: "postgres",
  database: "billing_dev",
  pool_size: 10

$ mix ecto.create && MIX_ENV=test mix ecto.create

start app

$ mix phx.server

or inside IEx:

$ iex -S mix phx.server

customize app

https://hexdocs.pm/phoenix/adding_pages.html

add useful packages

for example:

  _mix.exs_

  defp deps do
    [
      # ...
+     {:appsignal, "~> 1.5"},
+     {:credo, "~> 0.9", only: [:dev, :test], runtime: false},
+     {:distillery, "~> 1.5", runtime: false},
+     {:edeliver, "~> 1.4"},
+     {:exconstructor, "~> 1.1.0"},
+     {:httpoison, "~> 1.0"},
+     {:jason, "~> 1.0"},
+     {:phoenix_slime, "~> 0.10.0"},
+     {:timex, "~> 3.1"}
    ]
  end

generate schemas

schemas only:

$ mix phx.gen.schema User users
$ mix phx.gen.schema Card cards
$ mix phx.gen.schema Transfer transfers
$ mix ecto.migrate

schemas with context and supplementary modules (including ChangesetView):

$ mix phx.gen.json Page Conversation conversations external_id:string \
  labels:array:string created_time:utc_datetime updated_time:utc_datetime
$ mix ecto.migrate

it’s not necessary to run MIX_ENV=test mix ecto.migrate since this alias is added by default in a newly generated Phoenix project:

# mix.exs

defmodule Lain.Mixfile do
  # ...
  defp aliases do
    [
      # ...
      test: ["ecto.create --quiet", "ecto.migrate", "test"]
    ]
  end
end

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