Module: Sensu::Server::Filter
- Included in:
- Process
- Defined in:
- lib/sensu/server/filter.rb
Constant Summary collapse
- EVAL_PREFIX =
"eval:".freeze
Instance Method Summary collapse
-
#action_subdued?(condition) ⇒ TrueClass, FalseClass
Determine if an action is subdued and if there is an exception.
-
#check_request_subdued?(check) ⇒ TrueClass, FalseClass
Determine if a check request is subdued, by conditions set in the check definition.
-
#eval_attribute_value(event, raw_eval_string, raw_value) ⇒ TrueClass, FalseClass
Ruby ‘eval()` a string containing an expression, within the scope/context of a sandbox.
-
#event_filter(filter_name, event) {|filtered| ... } ⇒ Object
Determine if an event is filtered by an event filter, standard or extension.
-
#event_filtered?(handler, event) {|filtered| ... } ⇒ Boolean
Determine if an event is filtered for a handler.
-
#filter_attributes_match?(event, filter_attributes, event_attributes = nil) ⇒ TrueClass, FalseClass
Determine if all filter attribute values match those of the corresponding event attributes.
-
#filter_event(handler, event) {|event| ... } ⇒ Object
Attempt to filter an event for a handler.
-
#handle_action?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event with an action should be handled.
-
#handle_severity?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event with a check severity will be handled.
-
#handler_subdued?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event handler is subdued, by conditions set in the check and/or the handler definition.
-
#handling_disabled?(event) ⇒ TrueClass, FalseClass
Determine if handling is disabled for an event.
-
#process_eval_string(event, raw_eval_string) ⇒ String
Process a filter eval attribute, a Ruby ‘eval()` string containing an expression to be evaluated within the scope/context of a sandbox.
-
#subdue_days?(condition) ⇒ TrueClass, FalseClass
Determine if the current day is subdued.
-
#subdue_exception?(condition) ⇒ TrueClass, FalseClass
Determine if there is an exception a period of time (window) that is subdued.
-
#subdue_time?(condition) ⇒ TrueClass, FalseClass
Determine if a period of time (window) is subdued.
Instance Method Details
#action_subdued?(condition) ⇒ TrueClass, FalseClass
Determine if an action is subdued and if there is an exception. This method makes use of ‘subdue_time?()`, `subdue_days?()`, and subdue_exception?().
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# File 'lib/sensu/server/filter.rb', line 76 def action_subdued?(condition) subdued = subdue_time?(condition) || subdue_days?(condition) subdued && !subdue_exception?(condition) end |
#check_request_subdued?(check) ⇒ TrueClass, FalseClass
Determine if a check request is subdued, by conditions set in the check definition. If any of the conditions are true, without an exception, the check request is subdued.
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# File 'lib/sensu/server/filter.rb', line 108 def check_request_subdued?(check) if check[:subdue] && check[:subdue][:at] == "publisher" action_subdued?(check[:subdue]) else false end end |
#eval_attribute_value(event, raw_eval_string, raw_value) ⇒ TrueClass, FalseClass
Ruby ‘eval()` a string containing an expression, within the scope/context of a sandbox. This method is for filter attribute values starting with “eval:”, with the Ruby expression following the colon. A single variable is provided to the expression, `value`, equal to the corresponding event attribute value. Dot notation tokens in the expression, e.g. `:::mysql.user:::`, are substituted with the corresponding event data values prior to evaluation. The expression is expected to return a boolean value.
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# File 'lib/sensu/server/filter.rb', line 211 def eval_attribute_value(event, raw_eval_string, raw_value) eval_string = process_eval_string(event, raw_eval_string) unless eval_string.nil? begin value = Marshal.load(Marshal.dump(raw_value)) !!Sandbox.eval(eval_string, value) rescue => error @logger.error("filter attribute eval error", { :event => event, :raw_eval_string => raw_eval_string, :raw_value => raw_value, :error => error.to_s }) false end else false end end |
#event_filter(filter_name, event) {|filtered| ... } ⇒ Object
Determine if an event is filtered by an event filter, standard or extension. This method first checks for the existence of a standard filter, then checks for an extension if a standard filter is not defined. The provided callback is called with a single parameter, indicating if the event was filtered by a filter. If a filter does not exist for the provided name, the event is not filtered.
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# File 'lib/sensu/server/filter.rb', line 274 def event_filter(filter_name, event) case when @settings.filter_exists?(filter_name) filter = @settings[:filters][filter_name] matched = filter_attributes_match?(event, filter[:attributes]) yield(filter[:negate] ? matched : !matched) when @extensions.filter_exists?(filter_name) extension = @extensions[:filters][filter_name] extension.safe_run(event) do |output, status| yield(status == 0) end else @logger.error("unknown filter", :filter_name => filter_name) yield(false) end end |
#event_filtered?(handler, event) {|filtered| ... } ⇒ Boolean
Determine if an event is filtered for a handler. If a handler specifies one or more filters, via ‘:filters` or `:filter`, the `event_filter()` method is called for each of them. If any of the filters return `true`, the event is filtered for the handler. If no filters are defined in the handler definition, the event is not filtered.
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# File 'lib/sensu/server/filter.rb', line 304 def event_filtered?(handler, event) if handler.has_key?(:filters) || handler.has_key?(:filter) filter_list = Array(handler[:filters] || handler[:filter]).dup filter = Proc.new do |filter_list| filter_name = filter_list.shift if filter_name.nil? yield(false) else event_filter(filter_name, event) do |filtered| filtered ? yield(true) : EM.next_tick { filter.call(filter_list) } end end end filter.call(filter_list) else yield(false) end end |
#filter_attributes_match?(event, filter_attributes, event_attributes = nil) ⇒ TrueClass, FalseClass
Determine if all filter attribute values match those of the corresponding event attributes. Attributes match if the value objects are equivalent, are both hashes with matching key/value pairs (recursive), have equal string values, or evaluate to true (Ruby eval).
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# File 'lib/sensu/server/filter.rb', line 241 def filter_attributes_match?(event, filter_attributes, event_attributes=nil) event_attributes ||= event filter_attributes.all? do |key, value_one| value_two = event_attributes[key] case when value_one == value_two true when value_one.is_a?(Hash) && value_two.is_a?(Hash) filter_attributes_match?(event, value_one, value_two) when value_one.to_s == value_two.to_s true when value_one.is_a?(String) && value_one.start_with?(EVAL_PREFIX) eval_attribute_value(event, value_one, value_two) else false end end end |
#filter_event(handler, event) {|event| ... } ⇒ Object
Attempt to filter an event for a handler. This method will check to see if handling is disabled, if the event action is handled, if the event check severity is handled, if the handler is subdued, and if the event is filtered by any of the filters specified in the handler definition.
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# File 'lib/sensu/server/filter.rb', line 334 def filter_event(handler, event) details = {:handler => handler, :event => event} = case when handling_disabled?(event) "event handling disabled for event" when !handle_action?(handler, event) "handler does not handle action" when !handle_severity?(handler, event) "handler does not handle event severity" when handler_subdued?(handler, event) "handler is subdued" end if @logger.info(, details) @in_progress[:events] -= 1 if @in_progress else event_filtered?(handler, event) do |filtered| unless filtered yield(event) else @logger.info("event was filtered", details) @in_progress[:events] -= 1 if @in_progress end end end end |
#handle_action?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event with an action should be handled. An event action of ‘:flapping` indicates that the event state is flapping, and the event should not be handled unless its handler has `:handle_flapping` set to `true`.
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# File 'lib/sensu/server/filter.rb', line 134 def handle_action?(handler, event) event[:action] != :flapping || (event[:action] == :flapping && !!handler[:handle_flapping]) end |
#handle_severity?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event with a check severity will be handled. Event handlers can specify the check severities they will handle, using the definition attribute ‘:severities`. The possible severities are “ok”, “warning”, “critical”, and “unknown”. Handler severity filtering is bypassed when the event `:action` is `:resolve`, if the check history contains one of the specified severities since the last OK result.
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# File 'lib/sensu/server/filter.rb', line 150 def handle_severity?(handler, event) if handler.has_key?(:severities) case event[:action] when :resolve event[:check][:history].reverse[1..-1].any? do |status| if status.to_i == 0 break false end severity = SEVERITIES[status.to_i] || "unknown" handler[:severities].include?(severity) end else severity = SEVERITIES[event[:check][:status]] || "unknown" handler[:severities].include?(severity) end else true end end |
#handler_subdued?(handler, event) ⇒ TrueClass, FalseClass
Determine if an event handler is subdued, by conditions set in the check and/or the handler definition. If any of the conditions are true, without an exception, the handler is subdued.
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# File 'lib/sensu/server/filter.rb', line 90 def handler_subdued?(handler, event) subdued = [] if handler[:subdue] subdued << action_subdued?(handler[:subdue]) end check = event[:check] if check[:subdue] && check[:subdue][:at] != "publisher" subdued << action_subdued?(check[:subdue]) end subdued.any? end |
#handling_disabled?(event) ⇒ TrueClass, FalseClass
Determine if handling is disabled for an event. Check definitions can disable event handling with an attribute, ‘:handle`, by setting it to `false`.
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# File 'lib/sensu/server/filter.rb', line 122 def handling_disabled?(event) event[:check][:handle] == false end |
#process_eval_string(event, raw_eval_string) ⇒ String
Process a filter eval attribute, a Ruby ‘eval()` string containing an expression to be evaluated within the scope/context of a sandbox. This methods strips away the expression prefix, `eval:`, and substitues any dot notation tokens with the corresponding event data values. If there are unmatched tokens, this method will return `nil`.
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# File 'lib/sensu/server/filter.rb', line 180 def process_eval_string(event, raw_eval_string) eval_string = raw_eval_string.slice(5..-1) eval_string, unmatched_tokens = substitute_tokens(eval_string, event) if unmatched_tokens.empty? eval_string else @logger.error("filter eval unmatched tokens", { :raw_eval_string => raw_eval_string, :unmatched_tokens => unmatched_tokens, :event => event }) nil end end |
#subdue_days?(condition) ⇒ TrueClass, FalseClass
Determine if the current day is subdued. The provided condition must have a list of ‘:days`, or false will be returned.
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# File 'lib/sensu/server/filter.rb', line 40 def subdue_days?(condition) if condition.has_key?(:days) days = condition[:days].map(&:downcase) days.include?(Time.now.strftime("%A").downcase) else false end end |
#subdue_exception?(condition) ⇒ TrueClass, FalseClass
Determine if there is an exception a period of time (window) that is subdued. The provided condition must have an ‘:exception`, containing one or more `:begin` and `:end` times, eg. “11:30:00 PM”, or `false` will be returned. If there are any exceptions to a subdued period of time, `true` will be returned.
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# File 'lib/sensu/server/filter.rb', line 60 def subdue_exception?(condition) if condition.has_key?(:exceptions) condition[:exceptions].any? do |exception| Time.now >= Time.parse(exception[:begin]) && Time.now <= Time.parse(exception[:end]) end else false end end |
#subdue_time?(condition) ⇒ TrueClass, FalseClass
Determine if a period of time (window) is subdued. The provided condition must have a ‘:begin` and `:end` time, eg. “11:30:00 PM”, or `false` will be returned.
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# File 'lib/sensu/server/filter.rb', line 16 def subdue_time?(condition) if condition.has_key?(:begin) && condition.has_key?(:end) begin_time = Time.parse(condition[:begin]) end_time = Time.parse(condition[:end]) if end_time < begin_time if Time.now < end_time begin_time = Time.parse("12:00:00 AM") else end_time = Time.parse("11:59:59 PM") end end Time.now >= begin_time && Time.now <= end_time else false end end |