152 lines
4.2 KiB
Ruby
152 lines
4.2 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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# Helper methods to interact with Prometheus network services & resources
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class PrometheusClient
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include Gitlab::Utils::StrongMemoize
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Error = Class.new(StandardError)
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QueryError = Class.new(Gitlab::PrometheusClient::Error)
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# Target number of data points for `query_range`.
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# Please don't exceed the limit of 11000 data points
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# See https://github.com/prometheus/prometheus/blob/91306bdf24f5395e2601773316945a478b4b263d/web/api/v1/api.go#L347
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QUERY_RANGE_DATA_POINTS = 600
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# Minimal value of the `step` parameter for `query_range` in seconds.
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QUERY_RANGE_MIN_STEP = 60
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# Key translation between RestClient and Gitlab::HTTP (HTTParty)
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RESTCLIENT_GITLAB_HTTP_KEYMAP = {
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ssl_cert_store: :cert_store
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}.freeze
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attr_reader :api_url, :options
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private :api_url, :options
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def initialize(api_url, options = {})
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@api_url = api_url.chomp('/')
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@options = options
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end
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def ping
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json_api_get('query', query: '1')
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end
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def proxy(type, args)
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path = api_path(type)
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get(path, args)
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rescue Gitlab::HTTP::ResponseError => ex
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raise PrometheusClient::Error, "Network connection error" unless ex.response && ex.response.try(:code)
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handle_response(ex.response)
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end
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def query(query, time: Time.now)
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get_result('vector') do
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json_api_get('query', query: query, time: time.to_f)
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end
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end
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def query_range(query, start: 8.hours.ago, stop: Time.now)
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start = start.to_f
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stop = stop.to_f
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step = self.class.compute_step(start, stop)
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get_result('matrix') do
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json_api_get(
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'query_range',
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query: query,
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start: start,
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end: stop,
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step: step
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)
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end
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end
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def label_values(name = '__name__')
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json_api_get("label/#{name}/values")
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end
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def series(*matches, start: 8.hours.ago, stop: Time.now)
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json_api_get('series', 'match': matches, start: start.to_f, end: stop.to_f)
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end
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def self.compute_step(start, stop)
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diff = stop - start
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step = (diff / QUERY_RANGE_DATA_POINTS).ceil
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[QUERY_RANGE_MIN_STEP, step].max
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end
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private
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def api_path(type)
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[api_url, 'api', 'v1', type].join('/')
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end
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def json_api_get(type, args = {})
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path = api_path(type)
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response = get(path, args)
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handle_response(response)
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rescue Gitlab::HTTP::ResponseError => ex
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raise PrometheusClient::Error, "Network connection error" unless ex.response && ex.response.try(:code)
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handle_response(ex.response)
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end
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def gitlab_http_key(key)
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RESTCLIENT_GITLAB_HTTP_KEYMAP[key] || key
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end
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def mapped_options
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options.keys.map { |k| [gitlab_http_key(k), options[k]] }.to_h
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end
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def http_options
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strong_memoize(:http_options) do
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{ follow_redirects: false }.merge(mapped_options)
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end
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end
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def get(path, args)
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Gitlab::HTTP.get(path, { query: args }.merge(http_options) )
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rescue SocketError
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raise PrometheusClient::Error, "Can't connect to #{api_url}"
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rescue OpenSSL::SSL::SSLError
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raise PrometheusClient::Error, "#{api_url} contains invalid SSL data"
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rescue Errno::ECONNREFUSED
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raise PrometheusClient::Error, 'Connection refused'
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end
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def handle_response(response)
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response_code = response.try(:code)
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response_body = response.try(:body)
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raise PrometheusClient::Error, "#{response_code} - #{response_body}" unless response_code
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json_data = parse_json(response_body) if [200, 400].include?(response_code)
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case response_code
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when 200
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json_data['data'] if response['status'] == 'success'
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when 400
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raise PrometheusClient::QueryError, json_data['error'] || 'Bad data received'
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else
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raise PrometheusClient::Error, "#{response_code} - #{response_body}"
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end
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end
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def get_result(expected_type)
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data = yield
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data['result'] if data['resultType'] == expected_type
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end
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def parse_json(response_body)
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JSON.parse(response_body)
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rescue JSON::ParserError
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raise PrometheusClient::Error, 'Parsing response failed'
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end
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end
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end
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