Hello,
I have a sample app and I want to dockerize it.
It’s just a sample app, and I want to create the db and run migrations when the containers are created.
This is what I have:
I’m using the container in this guide:
I added this line in prod.secret.exs
database_url = “ecto://postgres:postgres@db/lists_dev”
This is a good way of setting the user, password and host for de database? Security it’s not an issue.
Created this module:
defmodule Lists.Release do
@moduledoc false
@start_apps [:postgrex, :ecto, :ecto_sql]
@myapps [:lists]
def create_and_migrate() do
createdb()
migrate()
end
def createdb do
# Start postgrex and ecto
IO.puts("Starting dependencies...")
# Start apps necessary for executing migrations
Enum.each(@start_apps, &Application.ensure_all_started/1)
Enum.each(@myapps, &create_db_for/1)
IO.puts("createdb task done!")
end
def create_db_for(app) do
for repo <- get_repos(app) do
:ok = ensure_repo_created(repo)
end
end
defp ensure_repo_created(repo) do
IO.puts("create #{inspect(repo)} database if it doesn't exist")
case repo.__adapter__.storage_up(repo.config) do
:ok -> :ok
{:error, :already_up} -> :ok
{:error, term} -> {:error, term}
end
end
def migrate() do
IO.puts("Start running migrations..")
Enum.each(@myapps, &run_migrations_for/1)
IO.puts("migrate task done!")
end
def run_migrations_for(app) do
IO.puts("Running migrations for '#{app}'")
for repo <- get_repos(app) do
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
end
IO.puts("Finished running migrations for '#{app}'")
end
defp get_repos(app) do
Application.load(app)
Application.fetch_env!(app, :ecto_repos)
end
def rollback(repo, version) do
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :down, to: version))
end
end
From a bash file that I called from the dockerfile I execute:
bin/lists eval "Lists.Release.create_and_migrate()"
bin="bin/lists"
# start the elixir application
exec "$bin" "start"
When I build the container I have this error.
** (RuntimeError) enviroment variable SECRET_KEY_BASE is missing. You can generate one by calling: mix phx.gen.secret
I tried to add to the dockerfile the line:
RUN mix phx.gen.secret
but It doesn’t work.
I know that this is a strange case, but I’m trying to end up with a dockerfile that could create the database, migrate and run by itself. Security it’s not an issue.
Thanks!
