PlugStatsd
==========
## Description
A plug for automatically sending
timing and count metrics to [statsd](https://github.com/etsy/statsd).
This plug can currently can use either of two statsd backends:
* [ex_statsd](https://github.com/CargoSense/ex_statsd)
* [statsderl](https://github.com/lpgauth/statsderl)
If you have additional statsd clients you'd like added, please open an [issue](https://github.com/jeffweiss/plug_statsd/issues/new)
and let me know.
## Usage
Add the plug and your chosen statsd backend as a dependencies for your application.
```elixir
defp deps do
[
{:plug_statsd, "~> 0.3"},
{:ex_statsd, "~> 0.5"},
]
end
```
You should also update your applications list to include the statsd plug and the backend:
```elixir
def application do
[applications: [:plug_statsd, :ex_statsd]]
end
```
Add the plug to your endpoints, here's an example from a Phoenix chat application (`lib/chat/endpoint.ex`)
```elixir
defmodule Chat.Endpoint do
...
plug Plug.Logger
#send connection request timing and counts to statsd
plug Plug.Statsd
...
end
```
Configure your statsd backend ([ex_statsd](https://github.com/CargoSense/ex_statsd) or [statderl](https://github.com/lpgauth/statsderl)) using `Mix.Config` as usual (probably in your
`config/`):
```elixir
use Mix.Config
config :ex_statsd,
host: "your.statsd.host.com", # This is optional and will default to 127.0.0.1
port: 1234, # This is optional and will default to 8125
namespace: "your-app" # This is optional and will default to nil
config :plug_statsd,
metrics: [
# custom_text.4xx.more_custom_text
{:timer, ["custom_text", :generalized_http_status, "more_custom_text"]},
# request.GET.api-v1-users-jeff=weiss
{:counter, ["request", &Plug.Statsd.http_method/2, :uri], sample_rate: 0.1},
# or this is equivalent as request.GET.api-v1-users-jeff=weiss
{:counter, ["request", {Plug.Statsd, :http_method}, :uri], sample_rate: 0.1},
],
slash_replacement: "-", # defaults to "."
dot_replacement: "=" # defaults to "_"
```
You can also add custom dynamic segments to your metric name by creating a 2-arity function that takes a `Plug.Conn` and a `Keyword` list.
## Seeing it in action
If you don't immediately have a statsd server available, you can run socat in a terminal.
```shell
$ socat UDP-RECV:8125 STDOUT
```
Depending on your sample rates, you should see a series of output that looks something like
```
custom_text.2xx.more_custom_text:27|ms
request.GET.[root]:1|c
custom_text.2xx.more_custom_text:18|ms
request.GET.[root]:1|c
custom_text.2xx.more_custom_text:32|ms
request.GET.[root]:1|c
custom_text.4xx.more_custom_text:1|ms
request.GET.api-v1-users-jeff=weiss:1|c
custom_text.4xx.more_custom_text:0|ms
request.GET.api-v1-users-jeff=weiss:1|c
```