Allow host.* fields to be disabled in Suricata module (elastic#19107)

If `forwarded` as configured as a tag (e.g. `var.tags: [forwarded]`) for the Suricata module then Filebeat will not add `host` fields to events. This is for use cases where Suricata is analyzing forwarded data (like from a network tap or mirror port).

Relates: elastic#13920

CHANGELOG.next.asciidoc

@@ -42,6 +42,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 * iptables {pull}18756[18756]
 * Checkpoint {pull}18754[18754]
 * Netflow {pull}19087[19087]
+* Suricata {pull}19107[19107] (`forwarded` tag is not included by default)
 - Preserve case of http.request.method.  ECS prior to 1.6 specified normalizing to lowercase, which lost information. Affects filesets: apache/access, elasticsearch/audit, iis/access, iis/error, nginx/access, nginx/ingress_controller, aws/elb, suricata/eve, zeek/http. {issue}18154[18154] {pull}18359[18359]
 - Adds check on `<no value>` config option value for the azure input `resource_manager_endpoint`. {pull}18890[18890]
 - Okta module now requires objects instead of JSON strings for the `http_headers`, `http_request_body`, `pagination`, `rate_limit`, and `ssl` variables. {pull}18953[18953]

filebeat/docs/modules/suricata.asciidoc

@@ -45,6 +45,12 @@ include::../include/config-option-intro.asciidoc[]
 
 include::../include/var-paths.asciidoc[]
 
+*`var.tags`*::
+
+A list of tags to include in events. Including `forwarded` indicates that the
+events did not originate on this host and causes `host.name` to not be added to
+events. Defaults to `[suricata]`.
+
 [float]
 === Example dashboard
 

x-pack/filebeat/module/suricata/_meta/docs.asciidoc

@@ -40,6 +40,12 @@ include::../include/config-option-intro.asciidoc[]
 
 include::../include/var-paths.asciidoc[]
 
+*`var.tags`*::
+
+A list of tags to include in events. Including `forwarded` indicates that the
+events did not originate on this host and causes `host.name` to not be added to
+events. Defaults to `[suricata]`.
+
 [float]
 === Example dashboard
 

x-pack/filebeat/module/suricata/eve/config/eve.yml

@@ -4,7 +4,8 @@ paths:
  - {{$path}}
 {{ end }}
 exclude_files: [".gz$"]
-tags: {{.tags}}
+tags: {{.tags | tojson}}
+publisher_pipeline.disable_host: {{ inList .tags "forwarded" }}
 
 processors:
   - rename:

x-pack/filebeat/module/suricata/eve/manifest.yml

@@ -13,8 +13,6 @@ var:
   - name: community_id
     default: true
 
-  # - name: nested_ecs
-  #   default: false
 ingest_pipeline: ingest/pipeline.yml
 input: config/eve.yml