ecto_repo_init_status_info in umbrella apps

[woylie]

We're having trouble making our Ecto repos appear in the dashboard in an umbrella application.

We have these apps:

• my_app: includes MyApp.Repo
• my_app_web: includes the Phoenix application

We put the prom_ex module into my_app_web, so that we can start it after the Phoenix endpoint. However, it seems that you are also expected to start prom_ex before the repo, so that it can get my_app_prom_ex_ecto_repo_init_status_info.

Is there a workaround for umbrella applications that we can use? Or would we have to add two separate prom_ex modules, one for each app?

Related issue: #190

[elvanja]

Have similar situation:

• main_app - with MainApp.Repo
• admin web - with Admin.Endpoint and router
• user web - with User.Endpoint and router

I tried doing it like this (stuff omitted for brevity):

Main app

defmodule MainApp.Application do
  def start(_type, _args) do
    children = [
      # Telemetry supervisor
      MainApp.Telemetry,
      # Start before Ecto, to be able to capture init events
      MainApp.Observability.PromEx,
      MainApp.Repo
    ]

    OpentelemetryEcto.setup(MainApp.Repo.config()[:telemetry_prefix])
  end
end

defmodule MainApp.Observability.PromEx do
  use PromEx, otp_app: :main_app

  def plugins do
    [
      Plugins.Application,
      Plugins.Beam,
      Plugins.Ecto
    ]
  end

  def dashboards do
    [
      {:prom_ex, "application.json"},
      {:prom_ex, "beam.json"},
      {:prom_ex, "ecto.json"},
      {:prom_ex, "plug_cowboy.json"},
      {:prom_ex, "plug_router.json"},
      {:prom_ex, "phoenix.json"}
    ]
  end
end

Admin Web

defmodule AdminWeb.Application do
  def start(_type, _args) do
    children = [
      AdminWeb.Endpoint,
      # Start after the Endpoint, to avoid unnecessary error messages
      AdminWeb.Observability.PromEx
    ]

    OpentelemetryPhoenix.setup(adapter: :cowboy, endpoint_prefix: [:phoenix, :endpoint, :admin_web])
  end
end

defmodule AdminWeb.Observability.PromEx do
  use PromEx, otp_app: :admin_web

  def plugins do
    [
      {Plugins.PlugRouter, routers: [AdminWeb.Router], event_prefix: [:admin_web, :router], ignore_routes: ["/metrics"]},
      {Plugins.Phoenix, router: AdminWeb.Router, endpoint: AdminWeb.Endpoint},
      Plugins.PhoenixLiveView
    ]
  end

  def dashboards do
    [
      {:prom_ex, "application.json"},
      {:prom_ex, "beam.json"},
      {:prom_ex, "ecto.json"},
      {:prom_ex, "plug_cowboy.json"},
      {:prom_ex, "plug_router.json"},
      {:prom_ex, "phoenix.json"}
    ]
  end
end

User Web

defmodule UserWeb.Application do
  def start(_type, _args) do
    children = [
      UserWeb.Endpoint,
      # Start after the Endpoint, to avoid unnecessary error messages
      UserWeb.Observability.PromEx
    ]

    OpentelemetryPhoenix.setup(adapter: :cowboy, endpoint_prefix: [:phoenix, :endpoint, :user_web])
  end
end

defmodule UserWeb.Observability.PromEx do
  use PromEx, otp_app: :user_web

  def plugins do
    [
      {Plugins.PlugRouter, routers: [UserWeb.Router], event_prefix: [:user_web, :router], ignore_routes: ["/metrics"]},
      {Plugins.Phoenix, router: UserWeb.Router, endpoint: UserWeb.Endpoint},
      Plugins.PhoenixLiveView
    ]
  end

  def dashboards do
    [
      {:prom_ex, "application.json"},
      {:prom_ex, "beam.json"},
      {:prom_ex, "ecto.json"},
      {:prom_ex, "plug_cowboy.json"},
      {:prom_ex, "plug_router.json"},
      {:prom_ex, "phoenix.json"}
    ]
  end
end

Each PromEx is configured the same, with grafana host details and each it's own configuration block.
I see dashboard folders for each app.
However, data is empty. E.g. no repo to choose for Ecto dashboard, and no instance either.
I see only metrics for :user_web app and only phoenix and phoenix live ones.

Any ideas what may be wrong?
Is it even possible to set it up for such an umbrella setup?
Thank you 🙇🏼

[elvanja]

Update: the :user_web app indeed has option to choose e.g. the repo for Ecto dashboard, but again no data. Other Ecto dashboards totally empty, filters included.