Getting Started

PhoenixSwagger provides a mix compiler and mix task phx.swagger.generate for the swagger-ui json file generation that contains swagger specification that describes API of the phoenix application.

You just need to add the swagger DSL to your controllers and then run this one mix task to generate the JSON files.

Installation

To use PhoenixSwagger with a phoenix application just add it to your list of dependencies in the mix.exs file:

def deps do
  [
    {:phoenix_swagger, "~> 0.8"},
    {:ex_json_schema, "~> 0.5"} # optional
  ]
end

ex_json_schema is an optional dependency of phoenix_swagger required only for schema validation plug and test helper.

Append :phoenix_swagger to the list of compilers to automatically update the swagger files each time the app is compiled:

def project do
[
  ...
  compilers: [:phoenix, :gettext] ++ Mix.compilers ++ [:phoenix_swagger],
  ...
end

Configuration

Add a config entry to your phoenix application specifying the output filename, router and endpoint modules used to generate the swagger file:

config :my_app, :phoenix_swagger,
  swagger_files: %{
    "priv/static/swagger.json" => [
      router: MyAppWeb.Router,     # phoenix routes will be converted to swagger paths
      endpoint: MyAppWeb.Endpoint  # (optional) endpoint config used to set host, port and https schemes.
    ]
  }

If multiple swagger files need to be generated, add additional entries to the project config:

config :my_app, :phoenix_swagger,
  swagger_files: %{
    "booking-api.json" => [router: MyApp.BookingRouter],
    "reports-api.json" => [router: MyApp.ReportsRouter],
    "admin-api.json" => [router: MyApp.AdminRouter]
  }

Also you can configure JSON library to use:

config :phoenix_swagger, json_library: Jason

Router

The outline of the swagger document should be returned from a swagger_info/0 function defined in your phoenix Router.ex module.

defmodule MyApp.Router do
  use MyApp.Web, :router

  pipeline :api do
    plug :accepts, ["json"]
  end

  scope "/api", MyApp do
    pipe_through :api
    resources "/users", UserController
  end

  def swagger_info do
    %{
      info: %{
        version: "1.0",
        title: "My App"
      }
    }
  end
end

The version and title are mandatory fields. By default the version will be 0.0.1 and the title will be <enter your title> if you do not provide swagger_info/0 function.

See the Swagger Object specification for details of other information that can be included. basePath is optional but may need to be specified if your API routes do not reside at the root location /. You can also set the description of tags here, for example:

%{
  basePath: "/api",
  info: %{..},
  tags: [%{name: "Users", description: "Operations about Users"}]
}

Endpoint

The swagger host value is built from your phoenix Endpoint url config.

# config.exs
config :my_app, MyApp.Web.Endpoint,
  url: [host: "localhost"], # "host": "localhost:4000" in generated swagger

If the host is configured to be set dynamically (either by {:systems, "VAR"} tuples or the :load_from_system_env flag), the swagger host will be omitted. SwaggerUI will default to sending requests to the same host that is serving the swagger file.

# prod.exs
config :my_app, MyApp.Web.Endpoint,
  load_from_system_env: true, # Expects url host and port to be configured in Endpoint.init callback
  url: [host: "example.com", port: 80],

Generate Swagger File

Once you have a minimal configuration and swagger_info function in the router, run the phx.swagger.generate mix task for the swagger JSON file generation into directory with phoenix application:

mix phx.swagger.generate