Add most (all?) the promex setup

config/dev.exs

@@ -58,6 +58,13 @@
 # https://dashbit.co/blog/speeding-up-re-compilation-of-elixir-projects
 config :phoenix, :plug_init_mode, :runtime
 
+config :pleroma, Pleroma.PromEx,
+  disabled: false,
+  manual_metrics_start_delay: :no_delay,
+  drop_metrics_groups: [],
+  grafana: :disabled,
+  metrics_server: :disabled
+
 if File.exists?("./config/dev.secret.exs") do
   import_config "dev.secret.exs"
 else

config/prod.exs

@@ -23,6 +23,20 @@
 config :logger, :console, level: :info
 config :logger, :ex_syslogger, level: :info
 
+# PromEx set up
+config :pleroma, Pleroma.Web.Plugs.MetricsPredicate,
+  auth_token: System.fetch_env!("PROMETHEUS_AUTH_TOKEN")
+
+config :pleroma, Pleroma.PromEx,
+  prometheus_data_source_id: System.fetch_env!("PROMETHEUS_DATASOURCE_ID"),
+  grafana: [
+    host: System.fetch_env!("GRAFANA_HOST"),
+    auth_token: System.fetch_env!("GRAFANA_AUTH_TOKEN"),
+    upload_dashboards_on_start: true,
+    folder_name: "Pleroma - PromEx",
+    annotate_app_lifecycle: true
+  ]
+
 # ## SSL Support
 #
 # To get SSL working, you will need to add the `https` key

lib/pleroma/application.ex

@@ -94,6 +94,7 @@ def start(_type, _args) do
     # Define workers and child supervisors to be supervised
     children =
       [
+        Pleroma.PromEx,
         Pleroma.Repo,
         Config.TransferTask,
         Pleroma.Emoji,

lib/pleroma/prom_ex.ex

@@ -0,0 +1,90 @@
+defmodule Pleroma.PromEx do
+  @moduledoc """
+  Be sure to add the following to finish setting up PromEx:
+
+  1. Update your configuration (config.exs, dev.exs, prod.exs, releases.exs, etc) to
+     configure the necessary bit of PromEx. Be sure to check out `PromEx.Config` for
+     more details regarding configuring PromEx:
+     ```
+     config :pleroma, Pleroma.PromEx,
+       disabled: false,
+       manual_metrics_start_delay: :no_delay,
+       drop_metrics_groups: [],
+       grafana: :disabled,
+       metrics_server: :disabled
+     ```
+
+  2. Add this module to your application supervision tree. It should be one of the first
+     things that is started so that no Telemetry events are missed. For example, if PromEx
+     is started after your Repo module, you will miss Ecto's init events and the dashboards
+     will be missing some data points:
+     ```
+     def start(_type, _args) do
+       children = [
+         Pleroma.PromEx,
+
+         ...
+       ]
+
+       ...
+     end
+     ```
+
+  3. Update your `endpoint.ex` file to expose your metrics (or configure a standalone
+     server using the `:metrics_server` config options). Be sure to put this plug before
+     your `Plug.Telemetry` entry so that you can avoid having calls to your `/metrics`
+     endpoint create their own metrics and logs which can pollute your logs/metrics given
+     that Prometheus will scrape at a regular interval and that can get noisy:
+     ```
+     defmodule PleromaWeb.Endpoint do
+       use Phoenix.Endpoint, otp_app: :pleroma
+
+       ...
+
+       plug PromEx.Plug, prom_ex_module: Pleroma.PromEx
+
+       ...
+     end
+     ```
+
+  4. Update the list of plugins in the `plugins/0` function return list to reflect your
+     application's dependencies. Also update the list of dashboards that are to be uploaded
+     to Grafana in the `dashboards/0` function.
+  """
+
+  use PromEx, otp_app: :pleroma
+
+  alias PromEx.Plugins
+
+  @impl true
+  def plugins do
+    [
+      # PromEx built in plugins
+      Plugins.Application,
+      Plugins.Beam,
+      {Plugins.Phoenix, router: Pleroma.Web.Router, endpoint: Pleroma.Web.Endpoint},
+      Plugins.Ecto,
+      Plugins.Oban
+    ]
+  end
+
+  @impl true
+  def dashboard_assigns do
+    [
+      datasource_id: "Prometheus",
+      default_selected_interval: "1m"
+    ]
+  end
+
+  @impl true
+  def dashboards do
+    [
+      # PromEx built in Grafana dashboards
+      {:prom_ex, "application.json"},
+      {:prom_ex, "beam.json"},
+      {:prom_ex, "phoenix.json"},
+      {:prom_ex, "ecto.json"},
+      {:prom_ex, "oban.json"}
+    ]
+  end
+end

lib/pleroma/web/endpoint.ex

@@ -12,6 +12,12 @@ defmodule Pleroma.Web.Endpoint do
   socket("/socket", Pleroma.Web.UserSocket)
   socket("/live", Phoenix.LiveView.Socket)
 
+  plug(Unplug,
+    if: Pleroma.Web.Plugs.MetricsPredicate,
+    do: {PromEx.Plug, path: "/api/metrics", prom_ex_module: Pleroma.PromEx}
+  )
+
+
   plug(Plug.Telemetry, event_prefix: [:phoenix, :endpoint])
 
   plug(Pleroma.Web.Plugs.SetLocalePlug)

lib/pleroma/web/plugs/metrics_predicate.ex

@@ -0,0 +1,29 @@
+defmodule Pleroma.Web.Plugs.MetricsPredicate do
+  @moduledoc """
+  This Unplug predicate is used to authorize requests to the PromEx metrics
+  """
+
+  @behaviour Unplug.Predicate
+
+  @impl true
+  def call(conn, _) do
+    conn
+    |> Plug.Conn.get_req_header("authorization")
+    |> case do
+      ["Bearer " <> token] ->
+        token == get_configured_auth_token()
+
+      [] ->
+        get_configured_auth_token() == :disabled
+
+      _ ->
+        false
+    end
+  end
+
+  defp get_configured_auth_token do
+    :pleroma
+    |> Application.get_env(__MODULE__, auth_token: "super_secret")
+    |> Keyword.get(:auth_token)
+  end
+end

mix.exs

@@ -205,6 +205,7 @@ defp deps do
       {:phoenix_live_dashboard, "~> 0.6.2"},
       {:ecto_psql_extras, "~> 0.6"},
       {:prom_ex, "~> 1.7.1"},
+      {:unplug, "~> 1.0"},
 
       # indirect dependency version override
       {:plug, "~> 1.10.4", override: true},

mix.lock

@@ -151,6 +151,7 @@
   "ueberauth_slack": {:hex, :ueberauth_slack, "0.3.0", "ec8f6c96e1d41a458a00b5d8cd918c1f387998884fe4636e67dd88b1bd06f928", [:mix], [{:oauth2, "~> 0.5", [hex: :oauth2, repo: "hexpm", optional: false]}, {:ueberauth, "~> 0.2", [hex: :ueberauth, repo: "hexpm", optional: false]}], "hexpm", "b4012b2cf1664dc80eda5762c5d3a495a819456186ab789da8ce4e7b9c0fa22f"},
   "ueberauth_twitter": {:hex, :ueberauth_twitter, "0.4.0", "4b98620341bc91bac90459093bba093c650823b6e2df35b70255c493c17e9227", [:mix], [{:httpoison, "~> 1.0", [hex: :httpoison, repo: "hexpm", optional: false]}, {:oauther, "~> 1.1", [hex: :oauther, repo: "hexpm", optional: false]}, {:ueberauth, "~> 0.6", [hex: :ueberauth, repo: "hexpm", optional: false]}], "hexpm", "fb29c9047ca263038c0c61f5a0ec8597e8564aba3f2b4cb02704b60205fd4468"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
+  "unplug": {:hex, :unplug, "1.0.0", "8ec2479de0baa9a6283c04a1cc616c5ca6c5b80b8ff1d857481bb2943368dbbc", [:mix], [{:plug, "~> 1.8", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm", "d171a85758aa412d4e85b809c203e1b1c4c76a4d6ab58e68dc9a8a8acd9b7c3a"},
   "unsafe": {:hex, :unsafe, "1.0.1", "a27e1874f72ee49312e0a9ec2e0b27924214a05e3ddac90e91727bc76f8613d8", [:mix], [], "hexpm", "6c7729a2d214806450d29766abc2afaa7a2cbecf415be64f36a6691afebb50e5"},
   "web_push_encryption": {:hex, :web_push_encryption, "0.3.1", "76d0e7375142dfee67391e7690e89f92578889cbcf2879377900b5620ee4708d", [:mix], [{:httpoison, "~> 1.0", [hex: :httpoison, repo: "hexpm", optional: false]}, {:jose, "~> 1.11.1", [hex: :jose, repo: "hexpm", optional: false]}], "hexpm", "4f82b2e57622fb9337559058e8797cb0df7e7c9790793bdc4e40bc895f70e2a2"},
   "websocket_client": {:git, "https://github.com/jeremyong/websocket_client.git", "9a6f65d05ebf2725d62fb19262b21f1805a59fbf", []},