# Instalando Oban A instação do Oban é bem simples, basta seguir o guia. Primeiro, vamos adicionar a dependência. 
defmodule CoffeeShop.MixProject do
  use Mix.Project

  # ...

  defp deps do
    [
      {:tesla, "~> 1.4"},
      {:bypass, "~> 2.1"},
      {:ecto_sql, "~> 3.0"},
      {:postgrex, ">= 0.0.0"},
      {:oban, "~> 2.17"}
    ]
  end
end
``` mix deps.get ``` ``` > mix deps.get Resolving Hex dependencies... Resolution completed in 0.06s New: jason 1.4.1 oban 2.17.8 Unchanged: bypass 2.1.0 cowboy 2.12.0 cowboy_telemetry 0.4.0 cowlib 2.13.0 db_connection 2.6.0 decimal 2.1.1 ecto 3.11.2 ecto_sql 3.11.1 mime 2.0.5 plug 1.15.3 plug_cowboy 2.7.1 plug_crypto 2.0.0 postgrex 0.17.5 ranch 1.8.0 telemetry 1.2.1 tesla 1.8.0 * Getting oban (Hex package) * Getting jason (Hex package) You have added/upgraded packages you could sponsor, run `mix hex.sponsor` to learn more ``` Oban utiliza a estratégia de migrações utilizando *Ecto*. Para isso, precisamos criar um nova migração utilizando [Ecto](https://hexdocs.pm/ecto_sql/Ecto.Migration.html). ``` mix ecto.gen.migration add_oban_jobs_table ``` ``` * creating priv/repo/migrations * creating priv/repo/migrations/20240415200026_add_oban_jobs_table.exs ``` Ele criará uma nova pasta chamada `priv/repo/migrations` que será onde nossas migrações irão viver. Também criará o arquivo de nosso migração. Vamos abrir ela. No meu caso é o arquivo `priv/repo/migrations/20240415200026_add_oban_jobs_table.exs`, mas para você terá um prefixo diferente, dependendo da data de criação. {% code title="priv/repo/migrations/20240415200026\_add\_oban\_jobs\_table.exs" lineNumbers="true" %} ```elixir defmodule CoffeeShop.Repo.Migrations.AddObanJobsTable do use Ecto.Migration def change do end end ``` {% endcode %} Primeiro vamos mudar de `change/0` para `up/0`, fazemos isso porque queremos que tenha o `up/0` e o `down/0`. `up/0` para rodar a migração e `down/0` para fazer o *rollback* caso necessário. Na função `up/0` iremos adicionar a configuração por meio de uma função e no `down/0`, fazermos o *downgrade* para a versão 1 zerando as dependência. 
defmodule CoffeeShop.Repo.Migrations.AddObanJobsTable do
  use Ecto.Migration

  def up do
    Oban.Migration.up(version: 12)
  end

  def down do
    Oban.Migration.down(version: 1)
  end
end
Precisamos agora rodar as migrações pendentes usando o comando do Ecto ```elixir mix ecto.migrate ``` ``` > mix ecto.migrate 17:07:47.213 [info] == Running 20240415200026 CoffeeShop.Repo.Migrations.AddObanJobsTable.up/0 forward 17:07:47.243 [info] execute "DO $$\nBEGIN\nIF NOT EXISTS (SELECT 1 FROM pg_type\n WHERE typname = 'oban_job_state'\n AND typnamespace = 'public'::regnamespace::oid) THEN\n CREATE TYPE \"public\".oban_job_state AS ENUM (\n 'available',\n 'scheduled',\n 'executing',\n 'retryable',\n 'completed',\n 'discarded'\n );\n END IF;\nEND$$;\n" 17:07:47.249 [info] create table if not exists public.oban_jobs 17:07:47.259 [info] create index if not exists public.oban_jobs_queue_index 17:07:47.263 [info] create index if not exists public.oban_jobs_state_index 17:07:47.267 [info] create index if not exists public.oban_jobs_scheduled_at_index 17:07:47.272 [info] execute "CREATE OR REPLACE FUNCTION \"public\".oban_jobs_notify() RETURNS trigger AS $$\nDECLARE\n channel text;\n notice json;\nBEGIN\n IF (TG_OP = 'INSERT') THEN\n channel = 'public.oban_insert';\n notice = json_build_object('queue', NEW.queue, 'state', NEW.state);\n\n -- No point triggering for a job that isn't scheduled to run now\n IF NEW.scheduled_at IS NOT NULL AND NEW.scheduled_at > now() AT TIME ZONE 'utc' THEN\n RETURN null;\n END IF;\n ELSE\n channel = 'public.oban_update';\n notice = json_build_object('queue', NEW.queue, 'new_state', NEW.state, 'old_state', OLD.state);\n END IF;\n\n PERFORM pg_notify(channel, notice::text);\n\n RETURN NULL;\nEND;\n$$ LANGUAGE plpgsql;\n" 17:07:47.274 [info] execute "DROP TRIGGER IF EXISTS oban_notify ON \"public\".oban_jobs" 17:07:47.276 [info] trigger "oban_notify" for relation "public.oban_jobs" does not exist, skipping 17:07:47.276 [info] execute "CREATE TRIGGER oban_notify\nAFTER INSERT OR UPDATE OF state ON \"public\".oban_jobs\nFOR EACH ROW EXECUTE PROCEDURE \"public\".oban_jobs_notify();\n" 17:07:47.279 [info] drop index if exists public.oban_jobs_scheduled_at_index 17:07:47.281 [info] create index public.oban_jobs_scheduled_at_index 17:07:47.285 [info] create check constraint worker_length on table public.oban_jobs 17:07:47.287 [info] create check constraint queue_length on table public.oban_jobs 17:07:47.289 [info] execute "CREATE OR REPLACE FUNCTION \"public\".oban_wrap_id(value bigint) RETURNS int AS $$\nBEGIN\n RETURN (CASE WHEN value > 2147483647 THEN mod(value, 2147483647) ELSE value END)::int;\nEND;\n$$ LANGUAGE plpgsql IMMUTABLE;\n" 17:07:47.291 [info] alter table public.oban_jobs 17:07:47.293 [info] execute "DROP FUNCTION IF EXISTS \"public\".oban_wrap_id(value bigint)" 17:07:47.294 [info] drop index if exists public.oban_jobs_scheduled_at_index 17:07:47.296 [info] drop index if exists public.oban_jobs_queue_index 17:07:47.297 [info] drop index if exists public.oban_jobs_state_index 17:07:47.299 [info] create index if not exists public.oban_jobs_queue_state_scheduled_at_id_index 17:07:47.303 [info] create index if not exists public.oban_jobs_attempted_at_id_index 17:07:47.307 [info] alter table public.oban_jobs 17:07:47.309 [info] alter table public.oban_jobs 17:07:47.312 [info] drop index if exists public.oban_jobs_queue_state_scheduled_at_id_index 17:07:47.314 [info] create index if not exists public.oban_jobs_state_queue_priority_scheduled_at_id_index 17:07:47.318 [info] execute "CREATE OR REPLACE FUNCTION \"public\".oban_jobs_notify() RETURNS trigger AS $$\nDECLARE\n channel text;\n notice json;\nBEGIN\n IF NEW.state = 'available' THEN\n channel = 'public.oban_insert';\n notice = json_build_object('queue', NEW.queue);\n\n PERFORM pg_notify(channel, notice::text);\n END IF;\n\n RETURN NULL;\nEND;\n$$ LANGUAGE plpgsql;\n" 17:07:47.320 [info] execute "DROP TRIGGER IF EXISTS oban_notify ON \"public\".oban_jobs" 17:07:47.322 [info] execute "CREATE TRIGGER oban_notify\nAFTER INSERT ON \"public\".oban_jobs\nFOR EACH ROW EXECUTE PROCEDURE \"public\".oban_jobs_notify();\n" 17:07:47.323 [info] alter table public.oban_jobs 17:07:47.331 [info] execute "DO $$\nDECLARE\n version int;\n already bool;\nBEGIN\n SELECT current_setting('server_version_num')::int INTO version;\n SELECT '{cancelled}' <@ enum_range(NULL::\"public\".oban_job_state)::text[] INTO already;\n\n IF already THEN\n RETURN;\n ELSIF version >= 120000 THEN\n ALTER TYPE \"public\".oban_job_state ADD VALUE IF NOT EXISTS 'cancelled';\n ELSE\n ALTER TYPE \"public\".oban_job_state RENAME TO old_oban_job_state;\n\n CREATE TYPE \"public\".oban_job_state AS ENUM (\n 'available',\n 'scheduled',\n 'executing',\n 'retryable',\n 'completed',\n 'discarded',\n 'cancelled'\n );\n\n ALTER TABLE \"public\".oban_jobs RENAME column state TO _state;\n ALTER TABLE \"public\".oban_jobs ADD state \"public\".oban_job_state NOT NULL default 'available';\n\n UPDATE \"public\".oban_jobs SET state = _state::text::\"public\".oban_job_state;\n\n ALTER TABLE \"public\".oban_jobs DROP column _state;\n DROP TYPE \"public\".old_oban_job_state;\n END IF;\nEND$$;\n" 17:07:47.333 [info] create index if not exists public.oban_jobs_state_queue_priority_scheduled_at_id_index 17:07:47.335 [info] relation "oban_jobs_state_queue_priority_scheduled_at_id_index" already exists, skipping 17:07:47.335 [info] alter table public.oban_jobs 17:07:47.340 [info] create check constraint priority_range on table public.oban_jobs 17:07:47.341 [info] create check constraint positive_max_attempts on table public.oban_jobs 17:07:47.343 [info] create check constraint attempt_range on table public.oban_jobs 17:07:47.345 [info] drop index if exists public.oban_jobs_args_vector 17:07:47.346 [info] index "oban_jobs_args_vector" does not exist, skipping 17:07:47.346 [info] drop index if exists public.oban_jobs_worker_gist 17:07:47.348 [info] index "oban_jobs_worker_gist" does not exist, skipping 17:07:47.348 [info] drop index if exists public.oban_jobs_attempted_at_id_index 17:07:47.349 [info] create index if not exists public.oban_jobs_args_index 17:07:47.351 [info] create index if not exists public.oban_jobs_meta_index 17:07:47.353 [info] create table if not exists public.oban_peers 17:07:47.360 [info] execute "ALTER TABLE \"public\".oban_peers SET UNLOGGED" 17:07:47.371 [info] drop constraint priority_range from table public.oban_jobs 17:07:47.373 [info] create check constraint non_negative_priority on table public.oban_jobs 17:07:47.374 [info] execute "DROP TRIGGER IF EXISTS oban_notify ON \"public\".oban_jobs" 17:07:47.376 [info] execute "DROP FUNCTION IF EXISTS \"public\".oban_jobs_notify()" 17:07:47.377 [info] execute "COMMENT ON TABLE \"public\".oban_jobs IS '12'" 17:07:47.381 [info] == Migrated 20240415200026 in 0.1s ``` Com isso criamos todas as tabelas necessárias para rodar o Oban. Agora iremos configurar sua utilização no projeto. Abra o arquivo `config/config.exs` 
import Config

config :coffee_shop,
  ecto_repos: [CoffeeShop.Repo]

config :coffee_shop, CoffeeShop.Repo,
  database: "coffee_shop_repo",
  username: "postgres",
  password: "postgres",
  hostname: "localhost"
  
config :coffee_shop, Oban,
  engine: Oban.Engines.Basic,
  queues: [default: 10],
  repo: CoffeeShop.Repo
Temos algumas configurações básicas da engine. Nela temos a quantidade por fila e o repositório que armazenaremos nossos *jobs*. Feito isso, pronto para produção, mas não para testes. Imagine rodar o Oban normalmente e o test ficar preso por horas por causa de um job que tem duração longa. Precisamos criar um tipo de *mock* para isso. O próprio Oban nos da esse super poder, precisando apenas so configurar ele no ambiente de teste. Para isso, vamos criar um arquivo em `config/test.exs` {% code title="config/test.exs" lineNumbers="true" %} ```elixir config :coffee_shop, Oban, testing: :inline ``` {% endcode %} A hierarquia de configurações ficará 1. Obtem as configuraçĩoes de config/config.ex 2. Estamos em ambietne de test, pegue as configurações de test e o que tiver de igual o de test mantem, sobrepondo o de config/config.exs. Finalmente precisamos adicionar o *Oban* a nossa arvore de supervisão, da mesma forma que adicionamos nosso `CoffeeShope.Repo`. Vamos em `lib/coffee_shop/application.ex` e colocar um novo filho a supervisão. 
defmodule CoffeeShop.Application do
  use Application

  def start(_type, _args) do
    children = [
      CoffeeShop.Repo,
      {Oban, Application.fetch_env!(:coffee_shop, Oban)}
    ]

    opts = [strategy: :one_for_one, name: CoffeeShop.Supervisor]

    Supervisor.start_link(children, opts)
  end
end
Utilizamos `Application.fetch_env!/2` para obter a configuração dos arquivos de configuração. Pronto. Para conseguir ver se tudo deu certo basta acessar o terminal iterativo e rodar `Oban.config:` ``` iex -S mix ``` ```elixir Oban.config() ``` ```elixir iex(1)> Oban.config() %Oban.Config{ dispatch_cooldown: 5, engine: Oban.Engines.Basic, get_dynamic_repo: nil, insert_trigger: true, log: false, name: Oban, node: "iago-effting", notifier: {Oban.Notifiers.Postgres, []}, peer: {Oban.Peers.Postgres, []}, plugins: [], prefix: "public", queues: [default: [limit: 10]], repo: CoffeeShop.Repo, shutdown_grace_period: 15000, stage_interval: 1000, testing: :disabled } ``` * [~~Configurar *Ecto* para se comunicar com *Postgres*~~](/problemas-de-api-externa/rate-limit-de-longa-duracao/adicionando-ecto-ao-projeto.md) * [~~Configurar *Oban*~~](/problemas-de-api-externa/rate-limit-de-longa-duracao/instalando-oban.md) Ótimo, Oban a postos. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://consumindo-apis-com-elixir.cafecomelixir.com.br/problemas-de-api-externa/rate-limit-de-longa-duracao/instalando-oban.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.