diff options
author | Reuben Pereira <rpereira@gitlab.com> | 2019-04-05 11:05:54 +0300 |
---|---|---|
committer | Sean McGivern <sean@gitlab.com> | 2019-04-05 11:05:54 +0300 |
commit | 7f529353e75852e62203eee3b8106b21dca068d9 (patch) | |
tree | d009d7fbd7c8cb6740cf6cdae30407f8b8582aa7 | |
parent | 88bf73a719933c136cc2bd9b791b6d5ca85cd330 (diff) |
Add a proxy method to PrometheusClient
- Also refactor the get and json_api_get methods so that the get method
can be reused by the new proxy method.
- The new proxy method makes no changes to the request to the prometheus
server and response from the prometheus server. This allows it to be
used as a proxy to the Prometheus server, hence the name.
-rw-r--r-- | app/services/prometheus/proxy_service.rb | 116 | ||||
-rw-r--r-- | lib/gitlab/prometheus_client.rb | 51 | ||||
-rw-r--r-- | spec/lib/gitlab/prometheus_client_spec.rb | 79 | ||||
-rw-r--r-- | spec/services/prometheus/proxy_service_spec.rb | 195 |
4 files changed, 419 insertions, 22 deletions
diff --git a/app/services/prometheus/proxy_service.rb b/app/services/prometheus/proxy_service.rb new file mode 100644 index 00000000000..c5d2b84878b --- /dev/null +++ b/app/services/prometheus/proxy_service.rb @@ -0,0 +1,116 @@ +# frozen_string_literal: true + +module Prometheus + class ProxyService < BaseService + include ReactiveCaching + include Gitlab::Utils::StrongMemoize + + self.reactive_cache_key = ->(service) { service.cache_key } + self.reactive_cache_lease_timeout = 30.seconds + self.reactive_cache_refresh_interval = 30.seconds + self.reactive_cache_lifetime = 1.minute + self.reactive_cache_worker_finder = ->(_id, *args) { from_cache(*args) } + + attr_accessor :proxyable, :method, :path, :params + + PROXY_SUPPORT = { + 'query' => { + method: ['GET'], + params: %w(query time timeout) + }, + 'query_range' => { + method: ['GET'], + params: %w(query start end step timeout) + } + }.freeze + + def self.from_cache(proxyable_class_name, proxyable_id, method, path, params) + proxyable_class = begin + proxyable_class_name.constantize + rescue NameError + nil + end + return unless proxyable_class + + proxyable = proxyable_class.find(proxyable_id) + + new(proxyable, method, path, params) + end + + # proxyable can be any model which responds to .prometheus_adapter + # like Environment. + def initialize(proxyable, method, path, params) + @proxyable = proxyable + @path = path + + # Convert ActionController::Parameters to hash because reactive_cache_worker + # does not play nice with ActionController::Parameters. + @params = filter_params(params, path).to_hash + + @method = method + end + + def id + nil + end + + def execute + return cannot_proxy_response unless can_proxy? + return no_prometheus_response unless can_query? + + with_reactive_cache(*cache_key) do |result| + result + end + end + + def calculate_reactive_cache(proxyable_class_name, proxyable_id, method, path, params) + return no_prometheus_response unless can_query? + + response = prometheus_client_wrapper.proxy(path, params) + + success(http_status: response.code, body: response.body) + rescue Gitlab::PrometheusClient::Error => err + service_unavailable_response(err) + end + + def cache_key + [@proxyable.class.name, @proxyable.id, @method, @path, @params] + end + + private + + def service_unavailable_response(exception) + error(exception.message, :service_unavailable) + end + + def no_prometheus_response + error('No prometheus server found', :service_unavailable) + end + + def cannot_proxy_response + error('Proxy support for this API is not available currently') + end + + def prometheus_adapter + strong_memoize(:prometheus_adapter) do + @proxyable.prometheus_adapter + end + end + + def prometheus_client_wrapper + prometheus_adapter&.prometheus_client_wrapper + end + + def can_query? + prometheus_adapter&.can_query? + end + + def filter_params(params, path) + params.slice(*PROXY_SUPPORT.dig(path, :params)) + end + + def can_proxy? + PROXY_SUPPORT.dig(@path, :method)&.include?(@method) + end + end +end diff --git a/lib/gitlab/prometheus_client.rb b/lib/gitlab/prometheus_client.rb index b4de7cd2bce..f13156f898e 100644 --- a/lib/gitlab/prometheus_client.rb +++ b/lib/gitlab/prometheus_client.rb @@ -24,6 +24,19 @@ module Gitlab json_api_get('query', query: '1') end + def proxy(type, args) + path = api_path(type) + get(path, args) + rescue RestClient::ExceptionWithResponse => ex + if ex.response + ex.response + else + raise PrometheusClient::Error, "Network connection error" + end + rescue RestClient::Exception + raise PrometheusClient::Error, "Network connection error" + end + def query(query, time: Time.now) get_result('vector') do json_api_get('query', query: query, time: time.to_f) @@ -64,22 +77,14 @@ module Gitlab private - def json_api_get(type, args = {}) - path = ['api', 'v1', type].join('/') - get(path, args) - rescue JSON::ParserError - raise PrometheusClient::Error, 'Parsing response failed' - rescue Errno::ECONNREFUSED - raise PrometheusClient::Error, 'Connection refused' + def api_path(type) + ['api', 'v1', type].join('/') end - def get(path, args) - response = rest_client[path].get(params: args) + def json_api_get(type, args = {}) + path = api_path(type) + response = get(path, args) handle_response(response) - rescue SocketError - raise PrometheusClient::Error, "Can't connect to #{rest_client.url}" - rescue OpenSSL::SSL::SSLError - raise PrometheusClient::Error, "#{rest_client.url} contains invalid SSL data" rescue RestClient::ExceptionWithResponse => ex if ex.response handle_exception_response(ex.response) @@ -90,8 +95,18 @@ module Gitlab raise PrometheusClient::Error, "Network connection error" end + def get(path, args) + rest_client[path].get(params: args) + rescue SocketError + raise PrometheusClient::Error, "Can't connect to #{rest_client.url}" + rescue OpenSSL::SSL::SSLError + raise PrometheusClient::Error, "#{rest_client.url} contains invalid SSL data" + rescue Errno::ECONNREFUSED + raise PrometheusClient::Error, 'Connection refused' + end + def handle_response(response) - json_data = JSON.parse(response.body) + json_data = parse_json(response.body) if response.code == 200 && json_data['status'] == 'success' json_data['data'] || {} else @@ -103,7 +118,7 @@ module Gitlab if response.code == 200 && response['status'] == 'success' response['data'] || {} elsif response.code == 400 - json_data = JSON.parse(response.body) + json_data = parse_json(response.body) raise PrometheusClient::QueryError, json_data['error'] || 'Bad data received' else raise PrometheusClient::Error, "#{response.code} - #{response.body}" @@ -114,5 +129,11 @@ module Gitlab data = yield data['result'] if data['resultType'] == expected_type end + + def parse_json(response_body) + JSON.parse(response_body) + rescue JSON::ParserError + raise PrometheusClient::Error, 'Parsing response failed' + end end end diff --git a/spec/lib/gitlab/prometheus_client_spec.rb b/spec/lib/gitlab/prometheus_client_spec.rb index 2517ee71f24..f15ae83a02c 100644 --- a/spec/lib/gitlab/prometheus_client_spec.rb +++ b/spec/lib/gitlab/prometheus_client_spec.rb @@ -60,15 +60,13 @@ describe Gitlab::PrometheusClient do end describe 'failure to reach a provided prometheus url' do - let(:prometheus_url) {"https://prometheus.invalid.example.com"} + let(:prometheus_url) {"https://prometheus.invalid.example.com/api/v1/query?query=1"} - subject { described_class.new(RestClient::Resource.new(prometheus_url)) } - - context 'exceptions are raised' do + shared_examples 'exceptions are raised' do it 'raises a Gitlab::PrometheusClient::Error error when a SocketError is rescued' do req_stub = stub_prometheus_request_with_exception(prometheus_url, SocketError) - expect { subject.send(:get, '/', {}) } + expect { subject } .to raise_error(Gitlab::PrometheusClient::Error, "Can't connect to #{prometheus_url}") expect(req_stub).to have_been_requested end @@ -76,7 +74,7 @@ describe Gitlab::PrometheusClient do it 'raises a Gitlab::PrometheusClient::Error error when a SSLError is rescued' do req_stub = stub_prometheus_request_with_exception(prometheus_url, OpenSSL::SSL::SSLError) - expect { subject.send(:get, '/', {}) } + expect { subject } .to raise_error(Gitlab::PrometheusClient::Error, "#{prometheus_url} contains invalid SSL data") expect(req_stub).to have_been_requested end @@ -84,11 +82,23 @@ describe Gitlab::PrometheusClient do it 'raises a Gitlab::PrometheusClient::Error error when a RestClient::Exception is rescued' do req_stub = stub_prometheus_request_with_exception(prometheus_url, RestClient::Exception) - expect { subject.send(:get, '/', {}) } + expect { subject } .to raise_error(Gitlab::PrometheusClient::Error, "Network connection error") expect(req_stub).to have_been_requested end end + + context 'ping' do + subject { described_class.new(RestClient::Resource.new(prometheus_url)).ping } + + it_behaves_like 'exceptions are raised' + end + + context 'proxy' do + subject { described_class.new(RestClient::Resource.new(prometheus_url)).proxy('query', { query: '1' }) } + + it_behaves_like 'exceptions are raised' + end end describe '#query' do @@ -258,4 +268,59 @@ describe Gitlab::PrometheusClient do it { is_expected.to eq(step) } end end + + describe 'proxy' do + context 'get API' do + let(:prometheus_query) { prometheus_cpu_query('env-slug') } + let(:query_url) { prometheus_query_url(prometheus_query) } + + around do |example| + Timecop.freeze { example.run } + end + + context 'when response status code is 200' do + it 'returns response object' do + req_stub = stub_prometheus_request(query_url, body: prometheus_value_body('vector')) + + response = subject.proxy('query', { query: prometheus_query }) + json_response = JSON.parse(response.body) + + expect(response.code).to eq(200) + expect(json_response).to eq({ + 'status' => 'success', + 'data' => { + 'resultType' => 'vector', + 'result' => [{ "metric" => {}, "value" => [1488772511.004, "0.000041021495238095323"] }] + } + }) + expect(req_stub).to have_been_requested + end + end + + context 'when response status code is not 200' do + it 'returns response object' do + req_stub = stub_prometheus_request(query_url, status: 400, body: { error: 'error' }) + + response = subject.proxy('query', { query: prometheus_query }) + json_response = JSON.parse(response.body) + + expect(req_stub).to have_been_requested + expect(response.code).to eq(400) + expect(json_response).to eq('error' => 'error') + end + end + + context 'when RestClient::Exception is raised' do + before do + stub_prometheus_request_with_exception(query_url, RestClient::Exception) + end + + it 'raises PrometheusClient::Error' do + expect { subject.proxy('query', { query: prometheus_query }) }.to( + raise_error(Gitlab::PrometheusClient::Error, 'Network connection error') + ) + end + end + end + end end diff --git a/spec/services/prometheus/proxy_service_spec.rb b/spec/services/prometheus/proxy_service_spec.rb new file mode 100644 index 00000000000..4bdb20de4c9 --- /dev/null +++ b/spec/services/prometheus/proxy_service_spec.rb @@ -0,0 +1,195 @@ +# frozen_string_literal: true + +require 'spec_helper' + +describe Prometheus::ProxyService do + include ReactiveCachingHelpers + + set(:project) { create(:project) } + set(:environment) { create(:environment, project: project) } + + describe '#initialize' do + let(:params) { ActionController::Parameters.new(query: '1').permit! } + + it 'initializes attributes' do + result = described_class.new(environment, 'GET', 'query', params) + + expect(result.proxyable).to eq(environment) + expect(result.method).to eq('GET') + expect(result.path).to eq('query') + expect(result.params).to eq('query' => '1') + end + + it 'converts ActionController::Parameters into hash' do + result = described_class.new(environment, 'GET', 'query', params) + + expect(result.params).to be_an_instance_of(Hash) + end + + context 'with unknown params' do + let(:params) { ActionController::Parameters.new(query: '1', other_param: 'val').permit! } + + it 'filters unknown params' do + result = described_class.new(environment, 'GET', 'query', params) + + expect(result.params).to eq('query' => '1') + end + end + end + + describe '#execute' do + let(:prometheus_adapter) { instance_double(PrometheusService) } + let(:params) { ActionController::Parameters.new(query: '1').permit! } + + subject { described_class.new(environment, 'GET', 'query', params) } + + context 'when prometheus_adapter is nil' do + before do + allow(environment).to receive(:prometheus_adapter).and_return(nil) + end + + it 'returns error' do + expect(subject.execute).to eq( + status: :error, + message: 'No prometheus server found', + http_status: :service_unavailable + ) + end + end + + context 'when prometheus_adapter cannot query' do + before do + allow(environment).to receive(:prometheus_adapter).and_return(prometheus_adapter) + allow(prometheus_adapter).to receive(:can_query?).and_return(false) + end + + it 'returns error' do + expect(subject.execute).to eq( + status: :error, + message: 'No prometheus server found', + http_status: :service_unavailable + ) + end + end + + context 'cannot proxy' do + subject { described_class.new(environment, 'POST', 'garbage', params) } + + it 'returns error' do + expect(subject.execute).to eq( + message: 'Proxy support for this API is not available currently', + status: :error + ) + end + end + + context 'with caching', :use_clean_rails_memory_store_caching do + let(:return_value) { { 'http_status' => 200, 'body' => 'body' } } + + let(:opts) do + [environment.class.name, environment.id, 'GET', 'query', { 'query' => '1' }] + end + + before do + allow(environment).to receive(:prometheus_adapter) + .and_return(prometheus_adapter) + allow(prometheus_adapter).to receive(:can_query?).and_return(true) + end + + context 'when value present in cache' do + before do + stub_reactive_cache(subject, return_value, opts) + end + + it 'returns cached value' do + result = subject.execute + + expect(result[:http_status]).to eq(return_value[:http_status]) + expect(result[:body]).to eq(return_value[:body]) + end + end + + context 'when value not present in cache' do + it 'returns nil' do + expect(ReactiveCachingWorker) + .to receive(:perform_async) + .with(subject.class, subject.id, *opts) + + result = subject.execute + + expect(result).to eq(nil) + end + end + end + + context 'call prometheus api' do + let(:prometheus_client) { instance_double(Gitlab::PrometheusClient) } + + before do + synchronous_reactive_cache(subject) + + allow(environment).to receive(:prometheus_adapter) + .and_return(prometheus_adapter) + allow(prometheus_adapter).to receive(:can_query?).and_return(true) + allow(prometheus_adapter).to receive(:prometheus_client_wrapper) + .and_return(prometheus_client) + end + + context 'connection to prometheus server succeeds' do + let(:rest_client_response) { instance_double(RestClient::Response) } + let(:prometheus_http_status_code) { 400 } + + let(:response_body) do + '{"status":"error","errorType":"bad_data","error":"parse error at char 1: no expression found in input"}' + end + + before do + allow(prometheus_client).to receive(:proxy).and_return(rest_client_response) + + allow(rest_client_response).to receive(:code) + .and_return(prometheus_http_status_code) + allow(rest_client_response).to receive(:body).and_return(response_body) + end + + it 'returns the http status code and body from prometheus' do + expect(subject.execute).to eq( + http_status: prometheus_http_status_code, + body: response_body, + status: :success + ) + end + end + + context 'connection to prometheus server fails' do + context 'prometheus client raises Gitlab::PrometheusClient::Error' do + before do + allow(prometheus_client).to receive(:proxy) + .and_raise(Gitlab::PrometheusClient::Error, 'Network connection error') + end + + it 'returns error' do + expect(subject.execute).to eq( + status: :error, + message: 'Network connection error', + http_status: :service_unavailable + ) + end + end + end + end + end + + describe '.from_cache' do + it 'initializes an instance of ProxyService class' do + result = described_class.from_cache( + environment.class.name, environment.id, 'GET', 'query', { 'query' => '1' } + ) + + expect(result).to be_an_instance_of(described_class) + expect(result.proxyable).to eq(environment) + expect(result.method).to eq('GET') + expect(result.path).to eq('query') + expect(result.params).to eq('query' => '1') + end + end +end |