[7.14] [Security Solutions][Detection Engine] Adds ability to ignore fields during alert indexing and a workaround for an EQL bug (#110927) #111174
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…during alert indexing and a workaround for an EQL bug (elastic#110927) ## Summary Adds a workaround for EQL bug: elastic/elasticsearch#77152 Adds the safety feature mentioned here: elastic#110802 Adds the ability to ignore particular [fields](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-fields.html#search-fields-param) when the field is merged with [_source](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-fields.html#source-filtering). Also fixes an EQL bug where EQL is introducing the meta field of `_ignored` within the fields and causing documents to not be indexable when we merge with the fields from EQL. Alerting document creation uses the fields API to get [runtime field](https://www.elastic.co/guide/en/elasticsearch/reference/current/runtime.html), [constant keyword](https://www.elastic.co/guide/en/elasticsearch/reference/master/keyword.html#constant-keyword-field-type), etc... that are only available within the [fields API](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-fields.html#search-fields-param) and then merges the field values not found within the `_source` document with the `_source` document and then finally indexes this merged document as an alert document. This fix/ability is a "safety feature" in that if a problematic [runtime field](https://www.elastic.co/guide/en/elasticsearch/reference/current/runtime.html), [constant keyword](https://www.elastic.co/guide/en/elasticsearch/reference/master/keyword.html#constant-keyword-field-type) is discovered or another bug along the stack we can set a `kibana.yml` key/value pair to ignore the problematic field. This _WILL NOT_ remove problematic fields from the `_source` document. This will only ignore problematic constant keyword, runtime fields, aliases, or anything else found in the fields API that is causing merge issues. This PR: * Adds a `alertIgnoreFields` `kibana.yml` array key with a default of an empty array if not specified. * Plumbs the `alertIgnoreFields` through the stack and into the fields/_source merge strategies of `missingFields` and `allFields` * Adds a temporary `isEqlBug77152` where it hard codes an ignore of `_ignored` until the EQL problem is fixed and then we will remove the workaround * Adds unit tests * Adds e2e tests which covers the described use cases above. The `alertIgnoreFields` key/value within `kibana.yml` if set should be an array of strings of each field you want to ignore. This can also contain regular expressions as long as they are of the form, `"/regex/"` in the array. Example if you want to ignore fields that are problematic called "host.name" and then one in which you want to ignore all fields that start with "user." using a regular expression: ```yml xpack.securitySolution.alertIgnoreFields: ['host.name', '/user\..*/'] ``` Although there are e2e tests which exercise the use cases... If you want to manual test the EQL bug fix you would add these documents in dev tools: ```json # Delete and add a mapping with a small ignore_above. DELETE eql-issue-ignore-fields-delme PUT eql-issue-ignore-fields-delme { "mappings" : { "dynamic": "strict", "properties" : { "@timestamp": { "type": "date" }, "some_keyword" : { "ignore_above": 5, "type" : "keyword" }, "other_keyword" : { "ignore_above": 10, "type" : "keyword" } } } } # Add a single document with one field that will be truncated and a second that will not. PUT eql-issue-ignore-fields-delme/_doc/1 { "@timestamp": "2021-09-02T04:13:05.626Z", "some_keyword": "longer than normal", "other_keyword": "normal" } ``` Then create an alert which queries everything from it: <img width="1155" alt="Screen Shot 2021-09-01 at 10 15 06 PM" src="https://user-images.githubusercontent.com/1151048/131781042-faa424cf-65a5-4ebb-b801-3f188940c81d.png"> and ensure signals are created: <img width="2214" alt="Screen Shot 2021-09-01 at 10 30 18 PM" src="https://user-images.githubusercontent.com/1151048/131782069-b9ab959c-f22d-44d5-baf0-561fe349c037.png"> To test the manual exclusions of any other problematic fields, create any index which has runtime fields or `constant keywords` but does not have anything within the `_source` document using dev tools. For example you can use `constant keyword` like so ```json PUT constant-keywords-deleme { "mappings": { "dynamic": "strict", "properties": { "@timestamp": { "type": "date" }, "testing_ignored": { "properties": { "constant": { "type": "constant_keyword", "value": "constant_value" } } }, "testing_regex": { "type": "constant_keyword", "value": "constant_value" }, "normal_constant": { "type": "constant_keyword", "value": "constant_value" }, "small_field": { "type": "keyword", "ignore_above": 10 } } } } PUT constant-keywords-deleme/_doc/1 { "@timestamp": "2021-09-02T04:20:01.760Z" } ``` Set in your `kibana.yml` the key/value of: ```yml xpack.securitySolution.alertIgnoreFields: ['testing_ignored.constant', '/.*_regex/'] ``` Setup a rule to run: <img width="1083" alt="Screen Shot 2021-09-01 at 10 23 23 PM" src="https://user-images.githubusercontent.com/1151048/131781696-fea0d421-836f-465c-9be6-5289fbb622a4.png"> Once it runs you should notice that the constant values for testing are not on the signals table since it only typically exists in the fields API: <img width="1166" alt="Screen Shot 2021-09-01 at 10 26 16 PM" src="https://user-images.githubusercontent.com/1151048/131781782-1684fb1d-bed9-4cf0-be9a-0abe1f0f34d1.png"> But the normal one still exists: <img width="1136" alt="Screen Shot 2021-09-01 at 10 26 31 PM" src="https://user-images.githubusercontent.com/1151048/131781827-5450c693-de9e-4285-b082-9f7a2cbd5d07.png"> If you change the `xpack.securitySolution.alertIgnoreFields` by removing it and re-generate the signals you will see these values added back. ### Checklist Delete any items that are not applicable to this PR. - [x] [Unit or functional tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html) were updated or added to match the most common scenarios - [x] If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the [docker list](https://github.com/elastic/kibana/blob/master/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker) # Conflicts: # src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/create_security_rule_type_factory.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/factories/utils/build_bulk_body.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/factories/wrap_hits_factory.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/indicator_match/create_indicator_match_alert_type.test.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/indicator_match/create_indicator_match_alert_type.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/ml/create_ml_alert_type.test.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/ml/create_ml_alert_type.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/query/create_query_alert_type.test.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/query/create_query_alert_type.ts # x-pack/plugins/security_solution/server/lib/detection_engine/rule_types/types.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/build_bulk_body.test.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/build_bulk_body.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/signal_rule_alert_type.test.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/signal_rule_alert_type.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/wrap_hits_factory.ts # x-pack/plugins/security_solution/server/lib/detection_engine/signals/wrap_sequences_factory.ts # x-pack/plugins/security_solution/server/plugin.ts # x-pack/test/detection_engine_api_integration/security_and_spaces/tests/index.ts
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Backports the following commits to 7.14: