Add latest changes from gitlab-org/gitlab@master

1 files changed, 83 insertions, 0 deletions

diff --git a/app/services/grafana/proxy_service.rb b/app/services/grafana/proxy_service.rb
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+++ b/app/services/grafana/proxy_service.rb
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+# frozen_string_literal: true
+
+# Proxies calls to a Grafana-integrated Prometheus instance
+# through the Grafana proxy API
+
+# This allows us to fetch and render metrics in GitLab from a Prometheus
+# instance for which dashboards are configured in Grafana
+module Grafana
+  class ProxyService < BaseService
+    include ReactiveCaching
+
+    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_worker_finder = ->(_id, *args) { from_cache(*args) }
+
+    attr_accessor :project, :datasource_id, :proxy_path, :query_params
+
+    # @param project_id [Integer] Project id for which grafana is configured.
+    #
+    # See #initialize for other parameters.
+    def self.from_cache(project_id, datasource_id, proxy_path, query_params)
+      project = Project.find(project_id)
+
+      new(project, datasource_id, proxy_path, query_params)
+    end
+
+    # @param project [Project] Project for which grafana is configured.
+    # @param datasource_id [String] Grafana datasource id for Prometheus instance
+    # @param proxy_path [String] Path to Prometheus endpoint; EX) 'api/v1/query_range'
+    # @param query_params [Hash<String, String>] Supported params: [query, start, end, step]
+    def initialize(project, datasource_id, proxy_path, query_params)
+      @project = project
+      @datasource_id = datasource_id
+      @proxy_path = proxy_path
+      @query_params = query_params
+    end
+
+    def execute
+      return cannot_proxy_response unless client
+
+      with_reactive_cache(*cache_key) { |result| result }
+    end
+
+    def calculate_reactive_cache(*)
+      return cannot_proxy_response unless client
+
+      response = client.proxy_datasource(
+        datasource_id: datasource_id,
+        proxy_path: proxy_path,
+        query: query_params
+      )
+
+      success(http_status: response.code, body: response.body)
+    rescue ::Grafana::Client::Error => error
+      service_unavailable_response(error)
+    end
+
+    # Required for ReactiveCaching; Usage overridden by
+    # self.reactive_cache_worker_finder
+    def id
+      nil
+    end
+
+    def cache_key
+      [project.id, datasource_id, proxy_path, query_params]
+    end
+
+    private
+
+    def client
+      project.grafana_integration&.client
+    end
+
+    def service_unavailable_response(exception)
+      error(exception.message, :service_unavailable)
+    end
+
+    def cannot_proxy_response
+      error('Proxy support for this API is not available currently')
+    end
+  end
+end