View Source Migrations
tasks
Tasks
The available tasks are:
mix ash_postgres.generate_migrations
mix ash_postgres.create
mix ash_postgres.drop
mix ash_postgres.migrate
(usemix ash_postgres.migrate --tenants
to run tenant migrations)
AshPostgres is built on top of ecto, so much of its behavior is pass-through/orchestration of that tooling.
basic-workflow
Basic Workflow
- Make resource changes
- Run
mix ash_postgres.generate_migrations
to generate migrations and resource snapshots - Run
mix ash_postgres.migrate
to run those migrations - Run
mix ash_postgres.migrate --tenants
as well if you have multi-tenant resources.
For more information on generating migrations, see the module documentation here:
Mix.Tasks.AshPostgres.GenerateMigrations
, or run mix help ash_postgres.generate_migrations
For running your migrations, there is a mix task that will find all of the repos configured in your apis and run their
migrations. It is a thin wrapper around mix ecto.migrate
. Ours is called mix ash_postgres.migrate
If you want to run or rollback individual migrations, use the corresponding
For tenant migrations (see the multitenancy guides for more) generated by multitenant resources, make sure you are using
mix ash_postgres.generate_migrations
. It is not sufficient to run mix ash_postgres.migrate --migrations_path tenant_migrations_path
. You will also need to define a list_tenants/0
function in your repo module. See AshPostgres.Repo
for more.
regenerating-migrations
Regenerating Migrations
Often, you will run into a situation where you want to make a slight change to a resource after you've already generated and run migrations. If you are using git and would like to undo those changes, then regenerate the migrations, this script may prove useful:
#!/bin/bash
# Get count of untracked migrations
N_MIGRATIONS=$(git ls-files --others priv/repo/migrations | wc -l)
# Rollback untracked migrations
mix ecto.rollback -n $N_MIGRATIONS
# Delete untracked migrations and snapshots
git ls-files --others priv/repo/migrations | xargs rm
git ls-files --others priv/resource_snapshots | xargs rm
# Regenerate migrations
mix ash_postgres.generate_migrations
# Run migrations if flag
if echo $* | grep -e "-m" -q
then
mix ecto.migrate
fi
After saving this file to something like regen.sh
, make it executable with chmod +x regen.sh
. Now you can run it with ./regen.sh
. If you would like the migrations to automatically run after regeneration, add the -m
flag: ./regen.sh -m
.
multiple-repos
Multiple Repos
If you are using multiple repos, you will likely need to use mix ecto.migrate
and manage it separately for each repo, as the options would
be applied to both repo, which wouldn't make sense.
running-migrations-in-production
Running Migrations in Production
Define a module similar to the following:
defmodule MyApp.Release do
@moduledoc """
Houses tasks that need to be executed in the released application (because mix is not present in releases).
"""
@app :my_ap
def migrate do
load_app()
for repo <- repos() do
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
end
end
# only needed if you are using postgres multitenancy
def migrate_tenants do
load_app()
for repo <- repos() do
repo_name = repo |> Module.split() |> List.last() |> Macro.underscore()
path =
"priv/"
|> Path.join(repo_name)
|> Path.join("tenant_migrations")
# This may be different for you if you are not using the default tenant migrations
{:ok, _, _} =
Ecto.Migrator.with_repo(
repo,
fn repo ->
for tenant <- repo.all_tenants() do
Ecto.Migrator.run(repo, path, :up, all: true, prefix: tenant)
end
end
)
end
end
# only needed if you are using postgres multitenancy
def migrate_all do
load_app()
migrate()
migrate_tenants()
end
def rollback(repo, version) do
load_app()
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :down, to: version))
end
# only needed if you are using postgres multitenancy
def rollback_tenants(repo, version) do
load_app()
repo_name = repo |> Module.split() |> List.last() |> Macro.underscore()
path =
"priv/"
|> Path.join(repo_name)
|> Path.join("tenant_migrations")
# This may be different for you if you are not using the default tenant migrations
for tenant <- repo.all_tenants() do
{:ok, _, _} =
Ecto.Migrator.with_repo(
repo,
&Ecto.Migrator.run(&1, path, :down,
to: version,
prefix: tenant
)
)
end
end
defp repos do
apis()
|> Enum.flat_map(fn api ->
api
|> Ash.Api.Info.resources()
|> Enum.map(&AshPostgres.repo/1)
end)
|> Enum.uniq()
end
defp apis do
Application.fetch_env!(:my_app, :ash_apis)
end
defp load_app do
Application.load(@app)
end
end