wip - e2e tests for distributed tracing

Author: solnic

.gitignore

@@ -17,3 +17,4 @@ test_integrations/phoenix_app/db
 
 test_integrations/*/_build
 test_integrations/*/deps
+test_integrations/*/test-results/

mix.exs

@@ -145,7 +145,11 @@ defmodule Sentry.Mixfile do
   defp aliases do
     [
       test: ["sentry.package_source_code", "test"],
-      "test.integrations": &run_integration_tests_if_supported/1
+      "test.integrations": &run_integration_tests_if_supported/1,
+      "test.tracing": ["sentry.tracing.test"],
+      "tracing.start": ["sentry.tracing.start"],
+      "tracing.phoenix": ["sentry.tracing.phoenix"],
+      "tracing.svelte": ["sentry.tracing.svelte"]
     ]
   end
 

test_integrations/phoenix_app/config/config.exs

@@ -65,6 +65,14 @@ config :opentelemetry, span_processor: {Sentry.OpenTelemetry.SpanProcessor, []}
 config :opentelemetry,
   sampler: {Sentry.OpenTelemetry.Sampler, [drop: ["Elixir.Oban.Stager process"]]}
 
+# Configure OpenTelemetry to use Sentry propagator for distributed tracing
+config :opentelemetry,
+  text_map_propagators: [
+    :trace_context,
+    :baggage,
+    Sentry.OpenTelemetry.Propagator
+  ]
+
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{config_env()}.exs"

test_integrations/phoenix_app/config/dev.exs

@@ -84,12 +84,19 @@ dsn =
     do: System.get_env("SENTRY_DSN_LOCAL"),
     else: System.get_env("SENTRY_DSN")
 
+# For e2e tracing tests, use the TestClient to log events to a file
+client =
+  if System.get_env("SENTRY_E2E_TEST_MODE") == "true",
+    do: PhoenixApp.TestClient,
+    else: Sentry.HackneyClient
+
 config :sentry,
   dsn: dsn,
   environment_name: :dev,
   enable_source_code_context: true,
   send_result: :sync,
-  traces_sample_rate: 1.0
+  traces_sample_rate: 1.0,
+  client: client
 
 config :phoenix_app, Oban,
   repo: PhoenixApp.Repo,

test_integrations/phoenix_app/lib/phoenix_app_web/controllers/page_controller.ex

@@ -48,4 +48,37 @@ defmodule PhoenixAppWeb.PageController do
 
     render(conn, :home, layout: false)
   end
+
+  # E2E tracing test endpoints
+  def api_error(_conn, _params) do
+    raise ArithmeticError, "bad argument in arithmetic expression"
+  end
+
+  def health(conn, _params) do
+    json(conn, %{status: "ok"})
+  end
+
+  def api_data(conn, _params) do
+    # Fetch actual data from the database
+    Tracer.with_span "fetch_data" do
+      users = Repo.all(User)
+
+      Tracer.with_span "process_data" do
+        # Do some processing
+        user_count = length(users)
+
+        # Make another query to demonstrate nested DB operations
+        first_user = Repo.get(User, 1)
+
+        json(conn, %{
+          message: "Data fetched successfully",
+          data: %{
+            user_count: user_count,
+            first_user: if(first_user, do: first_user.name, else: nil),
+            timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
+          }
+        })
+      end
+    end
+  end
 end

test_integrations/phoenix_app/lib/phoenix_app_web/endpoint.ex

@@ -44,6 +44,25 @@ defmodule PhoenixAppWeb.Endpoint do
   plug Plug.RequestId
   plug Plug.Telemetry, event_prefix: [:phoenix, :endpoint]
 
+  # Simple CORS handler for e2e tests
+  plug :cors
+
+  defp cors(conn, _opts) do
+    conn
+    |> put_resp_header("access-control-allow-origin", "*")
+    |> put_resp_header("access-control-allow-methods", "GET, POST, PUT, DELETE, OPTIONS")
+    |> put_resp_header("access-control-allow-headers", "content-type, sentry-trace, baggage")
+    |> then(fn conn ->
+      if conn.method == "OPTIONS" do
+        conn
+        |> send_resp(200, "")
+        |> halt()
+      else
+        conn
+      end
+    end)
+  end
+
   plug Plug.Parsers,
     parsers: [:urlencoded, :multipart, :json],
     pass: ["*/*"],

test_integrations/phoenix_app/lib/phoenix_app_web/router.ex

@@ -12,6 +12,14 @@ defmodule PhoenixAppWeb.Router do
 
   pipeline :api do
     plug :accepts, ["json"]
+    plug :put_cors_headers
+  end
+
+  defp put_cors_headers(conn, _opts) do
+    conn
+    |> put_resp_header("access-control-allow-origin", "*")
+    |> put_resp_header("access-control-allow-methods", "GET, POST, PUT, DELETE, OPTIONS")
+    |> put_resp_header("access-control-allow-headers", "content-type, authorization, sentry-trace, baggage")
   end
 
   scope "/", PhoenixAppWeb do
@@ -32,6 +40,15 @@ defmodule PhoenixAppWeb.Router do
     live "/users/:id/show/edit", UserLive.Show, :edit
   end
 
+  # API endpoints for e2e tracing tests
+  scope "/", PhoenixAppWeb do
+    pipe_through :api
+
+    get "/error", PageController, :api_error
+    get "/health", PageController, :health
+    get "/api/data", PageController, :api_data
+  end
+
   # Other scopes may use custom stacks.
   # scope "/api", PhoenixAppWeb do
   #   pipe_through :api

test_integrations/phoenix_app/test/phoenix_app_web/controllers/transaction_test.exs

@@ -129,4 +129,29 @@ defmodule Sentry.Integrations.Phoenix.TransactionTest do
 
     refute mount_transaction.contexts.trace.trace_id == handle_params_transaction.contexts.trace.trace_id
   end
+
+  test "GET /users with distributed tracing headers includes child spans with details", %{conn: conn} do
+    trace_id = "1234567890abcdef1234567890abcdef"
+    span_id = "1234567890abcdef"
+    sentry_trace = "#{trace_id}-#{span_id}-1"
+
+    conn = put_req_header(conn, "sentry-trace", sentry_trace)
+    get(conn, ~p"/users")
+
+    transactions = Sentry.Test.pop_sentry_transactions()
+
+    assert length(transactions) == 2
+
+    assert [mount_transaction, _handle_params_transaction] = transactions
+
+    assert mount_transaction.contexts.trace.trace_id == trace_id
+    assert mount_transaction.contexts.trace.parent_span_id != nil
+
+    assert [span_ecto] = mount_transaction.spans
+    assert span_ecto.op == "db"
+
+    assert span_ecto.description == "SELECT u0.\"id\", u0.\"name\", u0.\"age\", u0.\"inserted_at\", u0.\"updated_at\" FROM \"users\" AS u0"
+
+    assert span_ecto.data["db.system"] != nil
+  end
 end