elixir dev in docker

https://elixirforum.com/t/elixir-phoenix-running-a-dev-setup-inside-docker/43269

Elixir+Phoenix - running a dev setup inside docker Phoenix Forum Questions / Help docker docker-compose phoenix Oct 2021 Feb/2023

tommica

1 Oct/2021 I’m a complete noob when it comes to docker and docker compose, but I wanted to share my configuration to get a phoenix project up and running - I would really appreciate if someone could go through these and tell me what I am doing wrong (or missed, or something else) - I really want to learn to work with proper CI/CD tools

Dockerfile

FROM elixir:latest

EXPOSE 4000

RUN apt-get update &&
apt-get install -y postgresql-client &&
apt-get install -y inotify-tools &&
apt-get install -y nodejs &&
curl -L https://npmjs.org/install.sh | sh &&
mix local.hex --force &&
mix archive.install hex phx_new --force &&
mix local.rebar --force

ENV APP_HOME /app RUN mkdir $APP_HOME WORKDIR $APP_HOME docker-compose.yml

version: "3"

services: phoenix: build: . volumes: - .:/app ports: - "4000:4000" environment: PGUSER: postgres PGPASSWORD: postgres PGDATABASE: myapp_dev PGHOST: db PGPORT: 5432 depends_on: - db command: - "./entrypoint.sh" db: image: postgres:13.4-alpine environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: postgres PGDATA: /var/lib/postgresql/data/pgdata restart: always volumes: - ./_pgdata:/var/lib/postgresql/data entrypoint.sh (remember to make it executable by running chmod +x entrypoint.sh )

#!/bin/bash

set -e

Ensure the app's dependencies are installed

mix deps.get

if [[ -f assets/package.json ]]; then

Install the app's dependencies with npm

cd assets npm install cd .. fi

Wait until Postgres is ready

while ! pg_isready -q -h $PGHOST -p $PGPORT -U $PGUSER do echo "$(date) - waiting for database to start" sleep 2 done

Create, migrate, and seed database if it doesn't exist.

if [[ -z psql -Atqc "\\list $PGDATABASE" ]]; then echo "Database $PGDATABASE does not exist. Creating..." createdb -E UTF8 $PGDATABASE -l en_US.UTF-8 -T template0 mix ecto.create mix ecto.migrate mix run priv/repo/seeds.exs echo "Database $PGDATABASE created." fi

mix phx.server .gitignore

...

Ignore docker related files.

/_pgdata config/dev.exs

username: System.get_env("PGUSER", "postgres"), password: System.get_env("PGPASSWORD", "postgres"), database: System.get_env("PGDATABASE", "myapp_dev"), hostname: System.get_env("PGHOST", "localhost"), port: String.to_integer(System.get_env("PGPORT", "5432")), And finally again in config/dev.exs change this too (this is what stumped me for a while, and when I realized the issue, I felt like an idiot - by default phoenix binds to localhost only, so it is only binded to the port 4000 inside the VM, so no matter how much you expose port 4000 and forward it, it will not be accessible outside of docker, so curl localhost:4000 would just return an empty response):