97 lines
2.7 KiB
Ruby
97 lines
2.7 KiB
Ruby
# frozen_string_literal: true
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# Performs checks on whether resources from Grafana can be handled
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# We have certain restrictions on which formats we accept.
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# Some are technical requirements, others are simplifications.
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module Grafana
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class Validator
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Error = Class.new(StandardError)
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attr_reader :grafana_dashboard, :datasource, :panel, :query_params
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UNSUPPORTED_GRAFANA_GLOBAL_VARS = %w(
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$__interval_ms
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$__timeFilter
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$__name
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$timeFilter
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$interval
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).freeze
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def initialize(grafana_dashboard, datasource, panel, query_params)
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@grafana_dashboard = grafana_dashboard
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@datasource = datasource
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@panel = panel
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@query_params = query_params
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end
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def validate!
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validate_query_params!
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validate_panel_type!
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validate_variable_definitions!
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validate_global_variables!
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validate_datasource! if datasource
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end
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def valid?
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validate!
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true
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rescue ::Grafana::Validator::Error
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false
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end
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private
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# See defaults in Banzai::Filter::InlineGrafanaMetricsFilter.
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def validate_query_params!
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return if [:from, :to].all? { |param| query_params.include?(param) }
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raise_error 'Grafana query parameters must include from and to.'
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end
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# We may choose to support other panel types in future.
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def validate_panel_type!
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return if panel && panel[:type] == 'graph' && panel[:lines]
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raise_error 'Panel type must be a line graph.'
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end
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# We must require variable definitions to create valid prometheus queries.
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def validate_variable_definitions!
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return unless grafana_dashboard[:dashboard][:templating]
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return if grafana_dashboard[:dashboard][:templating][:list].all? do |variable|
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query_params[:"var-#{variable[:name]}"].present?
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end
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raise_error 'All Grafana variables must be defined in the query parameters.'
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end
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# We may choose to support further Grafana variables in future.
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def validate_global_variables!
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return unless panel_contains_unsupported_vars?
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raise_error "Prometheus must not include #{UNSUPPORTED_GRAFANA_GLOBAL_VARS}"
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end
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# We may choose to support additional datasources in future.
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def validate_datasource!
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return if datasource[:access] == 'proxy' && datasource[:type] == 'prometheus'
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raise_error 'Only Prometheus datasources with proxy access in Grafana are supported.'
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end
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def panel_contains_unsupported_vars?
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panel[:targets].any? do |target|
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UNSUPPORTED_GRAFANA_GLOBAL_VARS.any? do |variable|
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target[:expr].include?(variable)
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end
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end
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end
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def raise_error(message)
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raise Validator::Error, message
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end
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end
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end
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