<h1 align="center">Alchemetrics Tesla</h1>
<p align="center">
<img alt="Alchemetrics Tesla" src="https://github.com/globocom/alchemetrics_tesla/blob/master/assets/alchemetrics_tesla.png?raw=true" width="128">
</p>
<p align="center">
Tesla middleware to report external call metrics.
</p>
<p align="center">
<a href="https://travis-ci.org/globocom/alchemetrics_tesla">
<img alt="Travis" src="https://travis-ci.org/globocom/alchemetrics_tesla.svg">
</a>
<a href="https://hex.pm/packages/alchemetrics_tesla">
<img alt="Hex" src="https://img.shields.io/hexpm/dt/alchemetrics_tesla.svg">
</a>
</p>
## About
Alchemetrics Tesla is a very simple middleware that report metrics like `response_time` and calls count.
## Installing
Add to your dependencies:
```elixir
def deps do
[{:alchemetrics_tesla, "~> 2.0"}]
end
```
## Usage
All you need to do is adding the middleware to your Tesla module, like this:
```elixir
defmodule PetsClient do
use Tesla
plug Tesla.Middleware.Alchemetrics
plug Tesla.Middleware.BaseUrl, "http://pets.api.com"
def dogs do
get("/v1/dogs/")
end
end
```
And when you make any request it will be automatically reported:
```elixir
### Sample call
PetsClient.dogs()
### What is reported
# Response time (avg, max, min, p99 and p95)
[
type: "external_call.response_time",
request_details: %{
service: "PetsClient",
domain: "pets.api.com",
method: :get,
port: 80,
protocol: "http",
}
]
# Calls count (last interval and total)
[
type: "external_call.count",
request_details: %{
service: "PetsClient",
domain: "pets.api.com",
method: :get,
port: 80,
protocol: "http",
},
response_details: %{
status_code: "200",
status_code_group: "2xx"
}
]
```
### Adding extra metric metadata
You can also add extra metadata:
```elixir
defmodule PetsClient do
use Tesla
plug Tesla.Middleware.Alchemetrics
plug Tesla.Middleware.BaseUrl, "http://pets.api.com"
def dogs do
get("/v1/dogs/", opts: [alchemetrics_metadata: %{route: "get.dogs"}])
end
def logged_user_pet(pet_id) do
get("/user/pets/#{pet_id}", opts: [alchemetrics_metadata: %{route: "get.user.pets.show"}])
end
end
```
This extra metadata will be added to `request_details` key:
```elixir
## Sample call (1)
PetsClient.logged_user_pet(100)
# Reported response time (avg, max, min, p99 and p95)
[
type: "external_call.response_time",
request_details: %{
service: "PetsClient",
domain: "pets.api.com",
method: :get,
port: 80,
protocol: "http",
},
extra: %{ route: "get.user.pets" }
]
## Sample call (2)
PetsClient.dogs()
# Reported response time (avg, max, min, p99 and p95)
[
type: "external_call.response_time",
request_details: %{
service: "PetsClient",
domain: "pets.api.com",
method: :get,
port: 80,
protocol: "http",
},
extra: %{ route: "get.dogs" }
]
```