Today we study new way to extend CloudForms API. Using this method,
we will create new model, which will collect information from other
models and transform it as we need. There is not easy way, but it's worth to try.
For example, we will create two models - MonthBilling and AllBilling.
Firstly, we look at model MonthBilling. This model will collect of information for the last month. MonthBilling
includes: name of services, number of vms, and cpu usage, memory usage,
net usage, disk usage and total cost.
This model is based on model MetricRollup and it contains information about accounts for cpu, memory, usage internet, usage disk space. Also, MetricRollup stores information about resources, for which the accounts are and time, during which the accounts are calculated.
In interface of MonthBilling we will use
ActsAsArModel which is provide dynamic AR-like model, where columns defined by hashes.
---
# Model MonthBilling
class MonthBilling < ActsAsArModel
@us = nil
set_columns_hash(
:id => :integer,
:name => :string,
:vms => :integer,
:cpu => :float,
:mem => :float,
:disk => :float,
:net => :float,
:tco => :float
)
def self.sortable?
true
end
def self.find(*args)
res = []
arg = *args
method = *args
first_arg = args.first.to_s
if (first_arg.eql?("all"))
if (args[1].nil?)
id_user = User.find_by_userid(@us)
services = Service.where(evm_owner_id: id_user.id)
res = ApiController.helpers.add_metrics(services,"month")
else
size_conditions = args[1][:conditions].size
res_string = ""
for i in 9 .. size_conditions
if ((args[1][:conditions][i].to_i)== 0 && !(args[1][:conditions][i].eql?("0")))
break
end
res_string+=args[1][:conditions][i]
end
if (args[1][:conditions][i].eql?(","))
res = self.find(:all)
else
res_number = res_string.to_i
res = self.find(res_number)
end
end
else
id_user = User.find_by_userid(@us)
services = Service.where(id: args.first.to_i, evm_owner_id: id_user.id)
res = ApiController.helpers.add_metrics(services,"month")
end
res
end
def self.auth_initiliaze(user)
@us = user
end
def self.count(*args)
id_user = User.find_by_userid(@us)
Service.where(evm_owner_id: id_user.id).count
end
def self.scoped(options = {})
self.find(:all)
end
end
You have to implement following methods:
-
self.count(*args): this method is needed for quick
information about count of billing. Billings are counted for each
service, and count of billing is equal to the count of services.
-
self.auth_initiliaze(user): this method is necessary for searching services, which are belong to this user.
@us is initialized before, in renderer.rb
-
self.find(*args): in this function search is based on arguments. If first argument -
id, then then result is based on this id (service is searched by id). If first argument -
:all, and second argument is null, then result is based on all services and all information about. If first argument -
:all, and second argument is not null, then second argument is parsed, and then result is based on results of parsing(if it is id in second arguments, then result is based on this id. In another case, result is based on all services). Required by
ActsAsArModel.
-
self.scoped(options = nil): required by RBAC (
${VMDB}/app/models/rbac.rb)
- attribute
id: it's required to create correct "href"s.
In
MonthBilling we will show billings for services belonging to user. So, to know what user work with our API, we will add function
self.auth_initiliaze in
${VMDB}/app/helpers/api_helper/renderer.rb
---
# $VMDB/app/helpers/api_helper/renderer.rb
module ApiHelper
module Renderer
#
# Helper proc for rendering a collection of type specified.
#
def render_collection_type(type, id, is_subcollection = false)
klass = collection_class(type)
if (klass.respond_to?(:auth_initiliaze))
klass.auth_initiliaze(@auth_user)
end
.....
Model
MonthBilling uses important function -
add_metrics. We save this method in
${VMDB}/app/helpers/api_helper/custom_helper.rb
---
# $VMDB/app/helpers/api_helper/custom_helper.rb
def add_metrics(services,time)
$api_log.info("[DBG] start IBAHelper.add_metrics()")
res = []
required_time = nil
if (time.to_s.eql?("month"))
required_time = Time.now - 1.month
elsif (time.to_s.eql?("week"))
required_time = Time.now - 1.week
elsif (time.to_s.eql?("day"))
required_time = Time.now - 1.day
end
array_vms = []
hash_services = {}
hash_billings = {}
hash_billings = Hash.new{|h,k| h[k]=Hash.new(&h.default_proc)}
services.map{|service|
hash_billings[service][:cpu] = 0
hash_billings[service][:mem] = 0
hash_billings[service][:net] = 0
hash_billings[service][:disk] = 0
hash_billings[service][:tco] = 0
service.vms.map{|vm| array_vms.push(vm.id) }
service.vms.map{|vm| hash_services[vm.id] = service }
}
resources = MetricRollup.select("resource_id, SUM(cpu_usage_rate_average) as cpu_usage_rate_average, SUM(mem_usage_absolute_average)as mem_usage_absolute_average, SUM(disk_usage_rate_average) as disk_usage_rate_average,SUM(net_usage_rate_average) as net_usage_rate_average").where(resource_type: 'VmOrTemplate', capture_interval_name: 'hourly', timestamp: (required_time..Time.now), resource_id: array_vms).group(:resource_id)
hash_services.each_pair do |key, value|
resource = resources.where(resource_id: key.to_i)
resource.each do |element|
$api_log.info("in element - #{key} => #{value}")
hash_billings[value][:cpu] += element.cpu_usage_rate_average.to_f
hash_billings[value][:mem] += element.mem_usage_absolute_average.to_f
hash_billings[value][:net] += element.net_usage_rate_average.to_f
hash_billings[value][:disk]+= element.disk_usage_rate_average.to_f
hash_billings[value][:tco] += element.cpu_usage_rate_average.to_f + element.mem_usage_absolute_average.to_f + element.net_usage_rate_average.to_f + element.disk_usage_rate_average.to_f
end
end
hash_billings.each_pair do |key, value|
if (time.to_s.eql?("month"))
$api_log.info("if (time.to_s.eql?(month)) - billinsg")
res.push(MonthBilling.new(id: key.id, name: key.name, vms: key.vms.size, cpu: value[:cpu], mem: value[:mem], disk: value[:disk], net: value[:net], tco: value[:tco]))
elsif (time.to_s.eql?("week"))
$api_log.info("if (time.to_s.eql?(week) - billings")
res.push(WeekBilling.new(id: key.id, name: key.name, vms: key.vms.size, cpu: value[:cpu], mem: value[:mem], disk: value[:disk], net: value[:net], tco: value[:tco]))
elsif (time.to_s.eql?("day"))
$api_log.info("if (time.to_s.eql?(day)) = billings")
res.push(DayBilling.new(id: key.id, name: key.name, vms: key.vms.size, cpu: value[:cpu], mem: value[:mem], disk: value[:disk], net: value[:net], tco: value[:tco]))
end
end
$api_log.info("[DBG] end IBAHelper.add_metrics()")
res
end
1. Firstly, time is calculated, according to argument
time.
2.Then hash of billings is initilizated. Hash contains information about
id, name of services and count of vms. Other attributes are zero. Also,
information about necessary id of vms is collected.
3. Information about cpu, memory and etc. is stored from model
MetricRollup, where id = id of vm, capture_interval - hourly, and information is collected for the last month.In hash of billings information about cpu, memory and etc. is summed.
4. According to argument
time, new
MonthBilling is created.
As you can see, according to argument
time, you can create other model like this, for example
WeekBilling.
And, you should to desribe model in
${VMDB}/config/api.yml
---
# $VMDB/config/api.yml
:billings_monthly:
:description: Billings
:options:
- :collection
:methods: *70174834086080
:klass: MonthBilling
.png)
