The name of a CloudEvents attribute. Currently, only a subset of attributes are supported for filtering. You can /eventarc/docs/list-providers#describe-provider. All triggers MUST provide a filter for the 'type' attribute.
Optional. The operator used for matching the events with the value of the filter. If not specified, only events that have an exact key-value pair specified in the filter are matched. The only allowed value is match-path-pattern.