Class: Prometheus::ApiClient::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/prometheus/api_client/client.rb

Overview

Client contains the implementation for a Prometheus compatible api_client.

Defined Under Namespace

Classes: RequestError

Constant Summary collapse

DEFAULT_ARGS =

Default paramters for creating default client

{
  url: 'http://localhost:9090',
  path: '/api/v1/',
  credentials: {},
  options: {
    open_timeout: 2,
    timeout: 5,
  },
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Client

Create a Prometheus API client:

A default client is created if options is omitted.

Parameters:

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :url (String) —

    Server base URL.

  • :credentials (Hash) —

    Authentication credentials.

  • :options (Hash) —

    Options used to define connection.

  • :headers (Hash) —

    Unencoded HTTP header key/value pairs.

  • :request (Hash) —

    Request options.

  • :ssl (Hash) —

    SSL options.

  • :proxy (String) —

    Proxy url.



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# File 'lib/prometheus/api_client/client.rb', line 37

def initialize(options = {})
  options = DEFAULT_ARGS.merge(options)

  @client = Faraday.new(
    faraday_options(options),
  ) do |f|
    f.adapter :net_http
  end
end

Instance Method Details

#faraday_headers(options) ⇒ Object

Helper function to evalueate the low level headers option



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# File 'lib/prometheus/api_client/client.rb', line 134

def faraday_headers(options)
  return options[:headers] if options[:headers]

  headers = options[:credentials]
  return unless headers && headers[:token]

  {
    Authorization: 'Bearer ' + headers[:token].to_s,
  }
end

#faraday_options(options) ⇒ Object

Helper function to create the args for the low level client



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# File 'lib/prometheus/api_client/client.rb', line 159

def faraday_options(options)
  {
    url: options[:url] + options[:path],
    proxy: faraday_proxy(options),
    ssl: faraday_ssl(options),
    headers: faraday_headers(options),
    request: faraday_request(options),
  }
end

#faraday_proxy(options) ⇒ Object

Helper function to evalueate the low level proxy option



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# File 'lib/prometheus/api_client/client.rb', line 113

def faraday_proxy(options)
  return options[:proxy] if options[:proxy]

  proxy = options[:options]
  proxy[:http_proxy_uri] if proxy[:http_proxy_uri]
end

#faraday_request(options) ⇒ Object

Helper function to evalueate the low level headers option



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# File 'lib/prometheus/api_client/client.rb', line 146

def faraday_request(options)
  return options[:request] if options[:request]

  request = options[:options]
  return unless request[:open_timeout] || request[:timeout]

  {
    open_timeout: request[:open_timeout],
    timeout: request[:timeout],
  }
end

#faraday_ssl(options) ⇒ Object

Helper function to evalueate the low level ssl option



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# File 'lib/prometheus/api_client/client.rb', line 121

def faraday_ssl(options)
  return options[:ssl] if options[:ssl]

  ssl = options[:options]
  return unless ssl[:verify_ssl] || ssl[:ssl_cert_store]

  {
    verify: ssl[:verify_ssl] != OpenSSL::SSL::VERIFY_NONE,
    cert_store: ssl[:ssl_cert_store],
  }
end

#get(command, options) ⇒ Object

Issues a get request to the low level client.



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# File 'lib/prometheus/api_client/client.rb', line 98

def get(command, options)
  @client.get(command, options)
end

#label(label, options = {}) ⇒ Object

Returns a list of label values for a provided label name:

No options used.

Parameters:

  • label (String) —

    Label name

  • options (Hash) (defaults to: {}) 


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# File 'lib/prometheus/api_client/client.rb', line 93

def label(label, options = {})
  run_command("label/#{label}/values", options)
end

#query(options) ⇒ Object

Evaluates an instant query at a single point in time:

The current server time is used if the time parameter is omitted.

Parameters:

  • options (Hash)

Options Hash (options):

  • :query (String) —

    Prometheus expression query string.

  • :time (String) —

    <rfc3339 | unix_timestamp> Evaluation timestamp. Optional.

  • :timeout (String) —

    Evaluation timeout. Optional. Defaults to and is capped by the value of the -query.timeout flag.



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# File 'lib/prometheus/api_client/client.rb', line 57

def query(options)
  run_command('query', options)
end

#query_range(options) ⇒ Object

Evaluates an expression query over a range of time:

The current server time is used if the time parameter is omitted.

Parameters:

  • options (Hash)

Options Hash (options):

  • :query (String) —

    Prometheus expression query string.

  • :start (String) —

    <rfc3339 | unix_timestamp> Start timestamp.

  • :end (String) —

    <rfc3339 | unix_timestamp> End timestamp.

  • :step (String) —

    <duration> Query resolution step width.

  • :timeout (String) —

    Evaluation timeout. Optional. Defaults to and is capped by the value of the -query.timeout flag.



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# File 'lib/prometheus/api_client/client.rb', line 73

def query_range(options)
  run_command('query_range', options)
end

#run_command(command, options) ⇒ Object

Issues a get request to the low level client, and evalueate the response JSON.



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# File 'lib/prometheus/api_client/client.rb', line 104

def run_command(command, options)
  response = get(command, options)

  JSON.parse(response.body)['data']
rescue StandardError => err
  raise RequestError, err.message
end

#targets(options = {}) ⇒ Object

Returns an overview of the current state of the Prometheus target discovery:

No options used.

Parameters:

  • options (Hash) (defaults to: {}) 


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# File 'lib/prometheus/api_client/client.rb', line 83

def targets(options = {})
  run_command('targets', options)
end