forked from
l4.pm/atvouch
dev vouch dev on at. thats about it
add http metrics
+144
-1
+2
-1
appview/config/test.exs
+2
-1
appview/config/test.exs
···
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3
config :atvouch,
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port: 4057,
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atvouch_did: "did:plc:test",
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atvouch_endpoint: "https://localhost:123"
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atvouch_endpoint: "https://localhost:123",
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metrics_token: "test-metrics-token"
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config :atvouch, Atvouch.Repo, pool: Ecto.Adapters.SQL.Sandbox
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config :atvouch, start_replicas: false
+2
appview/lib/atvouch/application.ex
+2
appview/lib/atvouch/application.ex
+50
appview/lib/atvouch/telemetry.ex
+50
appview/lib/atvouch/telemetry.ex
···
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defmodule Atvouch.Telemetry do
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@moduledoc false
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require Logger
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use Prometheus.Metric
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@handler_id "atvouch-bandit-metrics"
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def setup do
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Histogram.declare(
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name: :http_request_duration_seconds,
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help: "HTTP request duration in seconds",
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labels: [:method, :route, :status],
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buckets: [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 3, 4, 5, 6, 7, 8, 10, 15, 20],
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duration_unit: false
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)
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Counter.declare(
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name: :http_requests_total,
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help: "Total number of HTTP requests",
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labels: [:method, :route, :status]
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)
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:telemetry.attach(
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@handler_id,
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[:bandit, :request, :stop],
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&__MODULE__.handle_request_stop/4,
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nil
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)
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end
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@doc false
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def handle_request_stop(_event, measurements, metadata, _config) do
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%{duration: duration} = measurements
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%{conn: conn} = metadata
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with %{plug_route: {route, _fun}} <- conn.private,
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false <- match?("/*" <> _, route) do
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# Strip the /*glob segment from forwarded routes (e.g. "/xrpc/*glob/dev.atvouch.alive")
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route = String.replace(route, "/*glob", "")
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duration_seconds = System.convert_time_unit(duration, :native, :microsecond) / 1_000_000
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labels = [conn.method, route, conn.status]
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Histogram.observe([name: :http_request_duration_seconds, labels: labels], duration_seconds)
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Counter.inc(name: :http_requests_total, labels: labels)
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else
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_ -> :ok
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end
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end
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end
+90
appview/test/atvouch/metrics_test.exs
+90
appview/test/atvouch/metrics_test.exs
···
1
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defmodule Atvouch.MetricsTest do
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use ExUnit.Case, async: false
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@metrics_token "test-metrics-token"
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setup do
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# Start a real Bandit server on a random port
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{:ok, server} = Bandit.start_link(plug: Atvouch.Router, port: 0, ip: {127, 0, 0, 1})
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{:ok, {_ip, port}} = ThousandIsland.listener_info(server)
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%{base_url: "http://127.0.0.1:#{port}", server: server}
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end
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test "GET /metrics requires authorization", %{base_url: base_url} do
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{:ok, resp} = http_get(base_url <> "/metrics")
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assert resp.status == 401
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end
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test "GET /metrics rejects invalid token", %{base_url: base_url} do
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{:ok, resp} = http_get(base_url <> "/metrics", [{"authorization", "Bearer wrong-token"}])
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assert resp.status == 403
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end
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test "bandit telemetry flows into prometheus metrics", %{base_url: base_url} do
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# Make a real request through Bandit so telemetry fires naturally
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{:ok, resp} = http_get(base_url <> "/health")
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assert resp.status == 200
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# Now check that /metrics captured it
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{:ok, resp} =
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http_get(base_url <> "/metrics", [{"authorization", "Bearer #{@metrics_token}"}])
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assert resp.status == 200
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assert resp.body =~ "http_request_duration_seconds"
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assert resp.body =~ "http_requests_total"
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assert resp.body =~ ~r/http_requests_total\{method="GET",route="\/health",status="200"\}/
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end
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test "unmatched routes are not recorded in metrics", %{base_url: base_url} do
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{:ok, resp} = http_get(base_url <> "/nonexistent")
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assert resp.status == 404
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{:ok, resp} =
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http_get(base_url <> "/metrics", [{"authorization", "Bearer #{@metrics_token}"}])
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refute resp.body =~ "/*_path"
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end
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defp http_get(url, headers \\ []) do
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uri = URI.parse(url)
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{:ok, conn} = Mint.HTTP.connect(:http, uri.host, uri.port)
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path =
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case uri.query do
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nil -> uri.path
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q -> "#{uri.path}?#{q}"
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end
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{:ok, conn, req_ref} = Mint.HTTP.request(conn, "GET", path, headers, nil)
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receive_response(conn, req_ref, %{status: nil, headers: [], body: ""})
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end
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defp receive_response(conn, req_ref, acc) do
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receive do
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message ->
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{:ok, conn, responses} = Mint.HTTP.stream(conn, message)
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+
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acc =
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Enum.reduce(responses, acc, fn
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{:status, ^req_ref, status}, acc -> %{acc | status: status}
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{:headers, ^req_ref, headers}, acc -> %{acc | headers: acc.headers ++ headers}
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{:data, ^req_ref, data}, acc -> %{acc | body: acc.body <> data}
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{:done, ^req_ref}, acc -> acc
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end)
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+
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if Enum.any?(responses, &match?({:done, ^req_ref}, &1)) do
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Mint.HTTP.close(conn)
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{:ok, acc}
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else
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receive_response(conn, req_ref, acc)
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end
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after
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5000 ->
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Mint.HTTP.close(conn)
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{:error, :timeout}
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end
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end
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end