WIP

lib/customer_service_web/api_spec.ex

@@ -0,0 +1,24 @@
+defmodule CustomerServiceWeb.ApiSpec do
+  alias OpenApiSpex.{OpenApi, Info, Server}
+  alias OpenApiSpex.{Info, OpenApi, Paths, Server}
+  alias CustomerServiceWeb.{Endpoint, Router}
+  @behaviour OpenApi
+
+  @impl OpenApi
+  def spec do
+    %OpenApi{
+      servers: [
+        # Populate the Server info from a phoenix endpoint
+        Server.from_endpoint(Endpoint)
+      ],
+      info: %Info{
+        title: "Customer Service",
+        version: "1.0"
+      },
+      # Populate the paths from a phoenix router
+      paths: Paths.from_router(Router)
+    }
+    # Discover request/response schemas from path specs
+    |> OpenApiSpex.resolve_schema_modules()
+  end
+end

lib/customer_service_web/controllers/customer.ex

@@ -0,0 +1,84 @@
+defmodule CustomerServiceWeb.Customer do
+  use CustomerServiceWeb, :controller
+
+  alias CustomerServiceWeb.Schemas.CreateCustomerRequest
+  alias CustomerServiceWeb.Schemas.CustomerResponse
+  alias CustomerService.Commands.CreateCustomer
+  alias CustomerService.CommandedApp
+  use OpenApiSpex.ControllerSpecs
+
+  tags ["Customers"]
+
+  operation :create,
+    summary: "Create customer",
+    request_body: {"Customer data", "application/json", CreateCustomerRequest},
+    responses: [
+      ok: {"Customer created", "application/json", CustomerResponse}
+    ]
+
+  def create(conn, params) do
+    customer_id = Ecto.UUID.generate()
+
+    command =
+      %CreateCustomer{
+        id: customer_id,
+        first_name: params["first_name"],
+        last_name: params["last_name"],
+        birth_date: Date.from_iso8601!(params["birth_date"]),
+        gender: params["gender"],
+        email: params["email"],
+        phone: params["phone"]
+      }
+
+    case CommandedApp.dispatch(command, consistency: :strong) do
+      :ok ->
+        json(conn, %{id: customer_id})
+
+      {:error, reason} ->
+        conn
+        |> put_status(:unprocessable_entity)
+        |> json(%{error: inspect(reason)})
+    end
+  end
+
+  operation :show,
+    summary: "Get customer",
+    parameters: [
+      id: [in: :path, type: :string, description: "Customer ID"]
+    ],
+    responses: [
+      ok: {"Customer", "application/json", CustomerResponse},
+      not_found: {"Not found", "application/json", nil}
+    ]
+
+  def show(conn, %{"id" => id}) do
+    case CustomerService.Repo.get(CustomerService.Projections.Customer, id) do
+      nil ->
+        send_resp(conn, 404, "")
+
+      customer ->
+        json(conn, customer)
+    end
+  end
+
+  operation :index,
+    summary: "List customers",
+    responses: [
+      ok:
+        {"Customer list", "application/json",
+         %OpenApiSpex.Schema{
+           type: :array,
+           items: CustomerResponse
+         }}
+    ]
+
+  def index(conn, _) do
+    case CustomerService.Repo.all(CustomerService.Projections.Customer) do
+      nil ->
+        send_resp(conn, 404, "")
+
+      customer ->
+        json(conn, customer)
+    end
+  end
+end

lib/customer_service_web/controllers/error_json.ex

@@ -0,0 +1,21 @@
+defmodule CustomerServiceWeb.ErrorJSON do
+  @moduledoc """
+  This module is invoked by your endpoint in case of errors on JSON requests.
+
+  See config/config.exs.
+  """
+
+  # If you want to customize a particular status code,
+  # you may add your own clauses, such as:
+  #
+  # def render("500.json", _assigns) do
+  #   %{errors: %{detail: "Internal Server Error"}}
+  # end
+
+  # By default, Phoenix returns the status message from
+  # the template name. For example, "404.json" becomes
+  # "Not Found".
+  def render(template, _assigns) do
+    %{errors: %{detail: Phoenix.Controller.status_message_from_template(template)}}
+  end
+end

lib/customer_service_web/endpoint.ex

@@ -0,0 +1,49 @@
+defmodule CustomerServiceWeb.Endpoint do
+  use Phoenix.Endpoint, otp_app: :customer_service
+
+  # The session will be stored in the cookie and signed,
+  # this means its contents can be read but not tampered with.
+  # Set :encryption_salt if you would also like to encrypt it.
+  @session_options [
+    store: :cookie,
+    key: "_customer_service_key",
+    signing_salt: "2Ese9Ehj",
+    same_site: "Lax"
+  ]
+
+  # socket "/live", Phoenix.LiveView.Socket,
+  #   websocket: [connect_info: [session: @session_options]],
+  #   longpoll: [connect_info: [session: @session_options]]
+
+  # Serve at "/" the static files from "priv/static" directory.
+  #
+  # When code reloading is disabled (e.g., in production),
+  # the `gzip` option is enabled to serve compressed
+  # static files generated by running `phx.digest`.
+  plug Plug.Static,
+    at: "/",
+    from: :customer_service,
+    gzip: not code_reloading?,
+    only: CustomerServiceWeb.static_paths(),
+    raise_on_missing_only: code_reloading?
+
+  # Code reloading can be explicitly enabled under the
+  # :code_reloader configuration of your endpoint.
+  if code_reloading? do
+    plug Phoenix.CodeReloader
+    plug Phoenix.Ecto.CheckRepoStatus, otp_app: :customer_service
+  end
+
+  plug Plug.RequestId
+  plug Plug.Telemetry, event_prefix: [:phoenix, :endpoint]
+
+  plug Plug.Parsers,
+    parsers: [:urlencoded, :multipart, :json],
+    pass: ["*/*"],
+    json_decoder: Phoenix.json_library()
+
+  plug Plug.MethodOverride
+  plug Plug.Head
+  plug Plug.Session, @session_options
+  plug CustomerServiceWeb.Router
+end

lib/customer_service_web/router.ex

@@ -0,0 +1,15 @@
+defmodule CustomerServiceWeb.Router do
+  use CustomerServiceWeb, :router
+
+  pipeline :api do
+    plug CORSPlug, origin: "*"
+    plug OpenApiSpex.Plug.PutApiSpec, module: CustomerServiceWeb.ApiSpec
+  end
+
+  scope "/api" do
+    pipe_through :api
+
+    resources "/customers", CustomerServiceWeb.Customer, only: [:create, :index, :show]
+    get "/openapi", OpenApiSpex.Plug.RenderSpec, []
+  end
+end

lib/customer_service_web/schemas/customer.ex

@@ -0,0 +1,38 @@
+defmodule CustomerServiceWeb.Schemas do
+  defmodule CustomerResponse do
+    require OpenApiSpex
+    alias OpenApiSpex.Schema
+
+    OpenApiSpex.schema(%{
+      title: "Customer",
+      type: :object,
+      properties: %{
+        id: %Schema{type: :string, format: :uuid},
+        first_name: %Schema{type: :string},
+        last_name: %Schema{type: :string},
+        birth_date: %Schema{type: :string, format: :date},
+        gender: %Schema{type: :string},
+        email: %Schema{type: :string, format: :email},
+        phone: %Schema{type: :string}
+      }
+    })
+  end
+
+  defmodule CreateCustomerRequest do
+    require OpenApiSpex
+    alias OpenApiSpex.Schema
+
+    OpenApiSpex.schema(%{
+      title: "CreateCustomer",
+      type: :object,
+      properties: %{
+        first_name: %Schema{type: :string},
+        last_name: %Schema{type: :string},
+        birth_date: %Schema{type: :string, format: :date},
+        gender: %Schema{type: :string},
+        email: %Schema{type: :string, format: :email},
+        phone: %Schema{type: :string}
+      }
+    })
+  end
+end

lib/customer_service_web/telemetry.ex

@@ -0,0 +1,93 @@
+defmodule CustomerServiceWeb.Telemetry do
+  use Supervisor
+  import Telemetry.Metrics
+
+  def start_link(arg) do
+    Supervisor.start_link(__MODULE__, arg, name: __MODULE__)
+  end
+
+  @impl true
+  def init(_arg) do
+    children = [
+      # Telemetry poller will execute the given period measurements
+      # every 10_000ms. Learn more here: https://hexdocs.pm/telemetry_metrics
+      {:telemetry_poller, measurements: periodic_measurements(), period: 10_000}
+      # Add reporters as children of your supervision tree.
+      # {Telemetry.Metrics.ConsoleReporter, metrics: metrics()}
+    ]
+
+    Supervisor.init(children, strategy: :one_for_one)
+  end
+
+  def metrics do
+    [
+      # Phoenix Metrics
+      summary("phoenix.endpoint.start.system_time",
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.endpoint.stop.duration",
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.router_dispatch.start.system_time",
+        tags: [:route],
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.router_dispatch.exception.duration",
+        tags: [:route],
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.router_dispatch.stop.duration",
+        tags: [:route],
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.socket_connected.duration",
+        unit: {:native, :millisecond}
+      ),
+      sum("phoenix.socket_drain.count"),
+      summary("phoenix.channel_joined.duration",
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.channel_handled_in.duration",
+        tags: [:event],
+        unit: {:native, :millisecond}
+      ),
+
+      # Database Metrics
+      summary("customer_service.repo.query.total_time",
+        unit: {:native, :millisecond},
+        description: "The sum of the other measurements"
+      ),
+      summary("customer_service.repo.query.decode_time",
+        unit: {:native, :millisecond},
+        description: "The time spent decoding the data received from the database"
+      ),
+      summary("customer_service.repo.query.query_time",
+        unit: {:native, :millisecond},
+        description: "The time spent executing the query"
+      ),
+      summary("customer_service.repo.query.queue_time",
+        unit: {:native, :millisecond},
+        description: "The time spent waiting for a database connection"
+      ),
+      summary("customer_service.repo.query.idle_time",
+        unit: {:native, :millisecond},
+        description:
+          "The time the connection spent waiting before being checked out for the query"
+      ),
+
+      # VM Metrics
+      summary("vm.memory.total", unit: {:byte, :kilobyte}),
+      summary("vm.total_run_queue_lengths.total"),
+      summary("vm.total_run_queue_lengths.cpu"),
+      summary("vm.total_run_queue_lengths.io")
+    ]
+  end
+
+  defp periodic_measurements do
+    [
+      # A module, function and arguments to be invoked periodically.
+      # This function must call :telemetry.execute/3 and a metric must be added above.
+      # {CustomerServiceWeb, :count_users, []}
+    ]
+  end
+end