https://github.com/scoutapp/elixir_plug_server_timing
Bring Elixir/Phoenix server-side performance metrics 📈 to Chrome's Developer Tools via the Server Timing API. Production Safe™.
https://github.com/scoutapp/elixir_plug_server_timing
elixir monitoring performance plug tracing
Last synced: 5 months ago
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Bring Elixir/Phoenix server-side performance metrics 📈 to Chrome's Developer Tools via the Server Timing API. Production Safe™.
- Host: GitHub
- URL: https://github.com/scoutapp/elixir_plug_server_timing
- Owner: scoutapp
- License: mit
- Created: 2018-03-05T16:55:57.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2018-12-15T21:16:53.000Z (about 7 years ago)
- Last Synced: 2024-05-16T17:03:16.294Z (over 1 year ago)
- Topics: elixir, monitoring, performance, plug, tracing
- Language: Elixir
- Homepage:
- Size: 39.1 KB
- Stars: 47
- Watchers: 6
- Forks: 2
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Server Timing Response Headers for Elixir / Phoenix
Bring Phoenix server-side performance metrics 📈 to Chrome's Developer Tools (and other browsers that support the [Server Timing API](https://w3c.github.io/server-timing/)) via the `plug_server_timing` package. Production Safe™.
Metrics are collected from the [scout_apm](https://github.com/scoutapp/scout_apm_elixir) package. A [Scout](https://scoutapp.com) account is not required.
## Browser Support
- Chrome 65+ (Chrome 64 uses an [old format](https://github.com/scoutapp/ruby_server_timing/issues/5#issuecomment-370504687) of the server timing headers. This isn't supported by the gem).
- Firefox 59+
- Opera 52+
## Installation
To install and use `PlugServerTiming`, add it as a dependency in your Mixfile:
```diff
# mix.exs
def deps do
[
# ...
+ {:plug_server_timing, "~> 0.0.2"}
]
end
```
Add `PlugServerTiming.Plug` to your Plug pipeline:
```diff
# lib/my_app_web/router.ex
defmodule MyAppWeb.Router do
pipeline :browser do
# ...
+ plug PlugServerTiming.Plug
end
end
```
✋Whoa! __We're not done yet__ ... we need to instrument our app's function calls.
## Instrumentation
Performance metrics are collected via the `scout_apm` gem. There's just a couple of steps to instrument your app.
__Instrument controllers:__
```diff
# lib/my_app_web.ex
defmodule MyAppWeb do
# ...
def controller do
quote do
use Phoenix.Controller, namespace: MyAppWeb
+ use ScoutApm.Instrumentation
# ...
end
end
end
```
__Instrument Ecto queries:__
```diff
# config/dev.exs
+config :my_app, MyApp.Repo,
+ loggers: [{Ecto.LogEntry, :log, []}, {ScoutApm.Instruments.EctoLogger, :log, []}]
```
__Instrument templates:__
```diff
# config/dev.exs
+config :phoenix, :template_engines,
+ eex: ScoutApm.Instruments.EExEngine,
+ exs: ScoutApm.Instruments.ExsEngine
```
### Additional instrumentation
To instrument HTTPoison, MongoDB Ecto, and more see the [Scout docs](http://help.apm.scoutapp.com/#instrumenting-common-libraries).
### Custom instrumentation
Collect performance data on additional function calls by adding custom instrumentation via `scout_apm`. [See the docs for instructions](http://help.apm.scoutapp.com/#elixir-custom-instrumentation).
## Security
If you'd like to conditionally include Server-Timing headers depending on authorization, the Plug can be included in a `Plug.Builder` pipeline or you can directly use `PlugServerTiming.Plug.register_before_send_headers/1` in an existing `Plug`.
```elixir
defmodule MyExistingAuthPlug do
@behaviour Plug
import Plug.Conn
def init(opts), do: opts
def call(conn, _opts) do
case AuthModule.verify_auth(conn) do
{:ok, :admin} ->
PlugServerTiming.Plug.register_before_send_headers(conn)
{:ok, :user} ->
conn
{:error, _} ->
conn
|> put_status(:unauthorized)
|> halt()
end
end
end
```
## Overhead
The `scout_apm` package, a dependency of `plug_server_timing`, applies low overhead instrumentation designed for production use.
## Thanks!
Special thank you goes to [@OleMchls](https://github.com/OleMchls) for writing up https://blog.dnsimple.com/2018/02/server-timing-with-phoenix/ and inspiring this package 💖
[Documentation on HexDocs](https://hexdocs.pm/plug_server_timing).