# Prometheus API Ruby Client

[![Gem Version][1]](http://badge.fury.io/rb/prometheus-api-client)
[![Build Status][2]](http://travis-ci.org/yaacov/prometheus_api_client_ruby)
[![Build Status][3]](https://codeclimate.com/github/yaacov/prometheus_api_client_ruby)
[![Coverage Status][4]](https://coveralls.io/github/yaacov/prometheus_api_client_ruby?branch=master)

A Ruby library for reading Prometheus metrics API.

## Install

```
gem install prometheus-api-client
```

## Usage

### Overview

```ruby
require 'prometheus/api_client'

# return a client for host http://localhost:9090/api/v1/
prometheus = Prometheus::ApiClient.client

prometheus.get(
  "query_range",
  :query => "sum(container_cpu_usage_seconds_total{container_name=\"prometheus-hgv4s\",job=\"kubernetes-nodes\"})",
  :start => "2015-07-01T20:10:30.781Z",
  :end   => "2015-07-02T20:10:30.781Z",
  :step  => "120s"
)
```

#### Changing server hostname

```ruby
# return a client for host http://example.com:9090/api/v1/
prometheus = Prometheus::ApiClient.client('http://example.com:9090')
```

#### Authentication proxy

If an authentication proxy ( e.g. oauth2 ) is used in a layer above the prometheus REST server, this client can use ssl and authentication headears.

```ruby
# return a client for host https://example.com/api/v1/ using a Bearer token "TopSecret"
prometheus = Prometheus::ApiClient.client('https://example.com:443', credentials: {token: 'TopSecret'})
```

#### High level calls

```ruby

# send a query request to server
prometheus.query(
  :query => "sum(container_cpu_usage_seconds_total{container_name=\"prometheus-hgv4s\",job=\"kubernetes-nodes\"})",
  :start => "2015-07-01T20:10:30.781Z",
  :end   => "2015-07-02T20:10:30.781Z"
)

# send a query_range request to server
prometheus.query_range(
  :query => "sum(container_cpu_usage_seconds_total{container_name=\"prometheus-hgv4s\",job=\"kubernetes-nodes\"})",
  :start => "2015-07-01T20:10:30.781Z",
  :end   => "2015-07-02T20:10:30.781Z",
  :step  => "120s"
)

# send a label request to server
prometheus.label('__name__')
```
## Tests

Install necessary development gems with `bundle install` and run tests with
rspec:

```bash
rake
```

[1]: https://badge.fury.io/rb/prometheus-api-client.svg
[2]: https://secure.travis-ci.org/yaacov/prometheus_api_client_ruby.svg
[3]: https://codeclimate.com/github/yaacov/prometheus_api_client_ruby.svg
[4]: https://coveralls.io/repos/github/yaacov/prometheus_api_client_ruby/badge.svg