Class: Etcd::Client

Inherits:
Object
  • Object
show all
Includes:
Keys, Mod::Leader, Mod::Lock, Stats
Defined in:
lib/etcd/client.rb

Overview

This is the central ruby class for Etcd. It provides methods for all etcd api calls. It also provides few additional methods beyond the core etcd api, like Etcd::Client#lock and Etcd::Client#eternal_watch, they are defined in separate modules and included in this class

Constant Summary collapse

HTTP_REDIRECT = 
->(r) { r.is_a? Net::HTTPRedirection }
HTTP_SUCCESS = 
->(r) { r.is_a? Net::HTTPSuccess }
HTTP_CLIENT_ERROR = 
->(r) { r.is_a? Net::HTTPClientError }

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Mod::Leader

#delete_leader, #get_leader, #mod_leader_endpoint, #set_leader

Methods included from Mod::Lock

#acquire_lock, #delete_lock, #get_lock, #lock, #mod_lock_endpoint, #renew_lock

Methods included from Keys

#compare_and_swap, #create, #create_in_order, #delete, #eternal_watch, #exists?, #get, #key_endpoint, #set, #update, #watch

Methods included from Stats

#stats, #stats_endpoint

Constructor Details

#initialize(opts = {}) ⇒ Client

Creates an Etcd::Client object. It accepts a hash opts as argument

rubocop:disable CyclomaticComplexity

Parameters:

  • opts (Hash) (defaults to: {}) —

    The options for new Etcd::Client object



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# File 'lib/etcd/client.rb', line 41

def initialize(opts = {})
  @host = opts[:host] || '127.0.0.1'
  @port = opts[:port] || 4001
  @read_timeout = opts[:read_timeout] || 60
  @allow_redirect = opts.key?(:allow_redirect) ? opts[:allow_redirect] : true
  @use_ssl = opts[:use_ssl] || false
  @verify_mode = opts.key?(:verify_mode) ? opts[:verify_mode] : OpenSSL::SSL::VERIFY_PEER
  @user_name = opts[:user_name] || nil
  @password = opts[:password] || nil
end

Instance Attribute Details

#allow_redirect ⇒ Object (readonly)

Returns the value of attribute allow_redirect.



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# File 'lib/etcd/client.rb', line 29

def allow_redirect
  @allow_redirect
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/etcd/client.rb', line 29

def host
  @host
end

#http ⇒ Object (readonly)

Returns the value of attribute http.



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# File 'lib/etcd/client.rb', line 29

def http
  @http
end

#password ⇒ Object (readonly)

Returns the value of attribute password.



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# File 'lib/etcd/client.rb', line 31

def password
  @password
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/etcd/client.rb', line 29

def port
  @port
end

#read_timeout ⇒ Object (readonly)

Returns the value of attribute read_timeout.



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# File 'lib/etcd/client.rb', line 30

def read_timeout
  @read_timeout
end

#use_ssl ⇒ Object (readonly)

Returns the value of attribute use_ssl.



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# File 'lib/etcd/client.rb', line 30

def use_ssl
  @use_ssl
end

#user_name ⇒ Object (readonly)

Returns the value of attribute user_name.



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# File 'lib/etcd/client.rb', line 31

def user_name
  @user_name
end

#verify_mode ⇒ Object (readonly)

Returns the value of attribute verify_mode.



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# File 'lib/etcd/client.rb', line 30

def verify_mode
  @verify_mode
end

Instance Method Details

#api_execute(path, method, options = {}) ⇒ Object

This method sends api request to etcd server.

This method has following parameters as argument

  • path - etcd server path (etcd server end point)

  • method - the request method used

  • options - any additional parameters used by request method (optional)

rubocop:disable MethodLength, CyclomaticComplexity



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# File 'lib/etcd/client.rb', line 80

def api_execute(path, method, options = {})
  params = options[:params]
  case  method
  when :get
    req = build_http_request(Net::HTTP::Get, path, params)
  when :post
    req = build_http_request(Net::HTTP::Post, path, nil, params)
  when :put
    req = build_http_request(Net::HTTP::Put, path, nil, params)
  when :delete
    req = build_http_request(Net::HTTP::Delete, path, params)
  else
    fail "Unknown http action: #{method}"
  end
  timeout = options[:timeout] || @read_timeout
  http = Net::HTTP.new(host, port)
  http.read_timeout = timeout
  http.use_ssl = use_ssl
  http.verify_mode = verify_mode
  req.basic_auth(user_name, password) if [user_name, password].all?
  Log.debug("Invoking: '#{req.class}' against '#{path}")
  res = http.request(req)
  Log.debug("Response code: #{res.code}")
  process_http_request(res, req, params)
end

#build_http_request(klass, path, params = nil, body = nil) ⇒ Object

rubocop:enable MethodLength



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# File 'lib/etcd/client.rb', line 133

def build_http_request(klass, path, params = nil, body = nil)
  path += '?' + URI.encode_www_form(params) unless params.nil?
  req = klass.new(path)
  req.body = URI.encode_www_form(body) unless body.nil?
  Etcd::Log.debug("Built #{klass} path:'#{path}'  body:'#{req.body}'")
  req
end

#leader ⇒ Object

Get the current leader



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# File 'lib/etcd/client.rb', line 69

def leader
  api_execute(version_prefix + '/leader', :get).body.strip
end

#machines ⇒ Object

Returns array of all machines in the cluster



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# File 'lib/etcd/client.rb', line 64

def machines
  api_execute(version_prefix + '/machines', :get).body.split(',').map(&:strip)
end

#process_http_request(res, req = nil, params = nil) ⇒ Object

need to ahve original request to process the response when it redirects



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# File 'lib/etcd/client.rb', line 107

def process_http_request(res, req = nil, params = nil)
  case res
  when HTTP_SUCCESS
    Log.debug('Http success')
    res
  when HTTP_REDIRECT
    if allow_redirect
      uri = URI(res['location'])
      @host = uri.host
      @port = uri.port
      Log.debug("Http redirect, setting new host to: #{@host}:#{@port}, and retrying")
      api_execute(uri.path, req.method.downcase.to_sym, params: params)
    else
      Log.debug('Http redirect not allowed')
      res.error!
    end
  when HTTP_CLIENT_ERROR
    fail Error.from_http_response(res)
  else
    Log.debug('Http error')
    Log.debug(res.body)
    res.error!
  end
end

#version ⇒ Object

Returns the etcd daemon version



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# File 'lib/etcd/client.rb', line 59

def version
  api_execute('/version', :get).body
end

#version_prefix ⇒ Object

Returns the etcd api version that will be used for across API methods



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# File 'lib/etcd/client.rb', line 54

def version_prefix
  '/v2'
end