Generate fields.go for netflow input

* Generate fields.go for netflow input

Update x-pack/filebeat to generate a fields.go for each input type. And update the code that
generates the include/list.go to import each input.

* Fix netflow exporter version datatype

It was "int" which is not a valid type. Changed it to long rather than integer because we use that everywhere for numbers.

Cherry-pick parts of 01ae538 (elastic#9686)

x-pack/filebeat/filebeat.reference.yml

@@ -791,6 +791,12 @@ filebeat.inputs:
 # This option is not supported on Windows.
 #filebeat.registry_file_permissions: 0600
 
+# The timeout value that controls when registry entries are written to disk
+# (flushed). When an unwritten update exceeds this value, it triggers a write to
+# disk. When registry_flush is set to 0s, the registry is written to disk after
+# each batch of events has been published successfully. The default value is 0s.
+#filebeat.registry_flush: 0s
+
 # By default Ingest pipelines are not updated if a pipeline with the same ID
 # already exists. If this option is enabled Filebeat overwrites pipelines
 # everytime a new Elasticsearch connection is established.

x-pack/filebeat/input/netflow/_meta/fields.header.yml

@@ -39,6 +39,6 @@
                 How long the exporter process has been running, in milliseconds.
 
             - name: version
-              type: int
+              type: long
               description: >
                 NetFlow version used.

x-pack/filebeat/input/netflow/_meta/fields.yml

@@ -39,7 +39,7 @@
                 How long the exporter process has been running, in milliseconds.
 
             - name: version
-              type: int
+              type: long
               description: >
                 NetFlow version used.
 

x-pack/filebeat/magefile.go

@@ -34,7 +34,7 @@ func Build() error {
 	return mage.Build(mage.DefaultBuildArgs())
 }
 
-// GolangCrossBuild build the Beat binary inside of the golang-builder.
+// GolangCrossBuild builds the Beat binary inside of the golang-builder.
 // Do not use directly, use crossBuild instead.
 func GolangCrossBuild() error {
 	return mage.GolangCrossBuild(mage.DefaultGolangCrossBuildArgs())
@@ -45,9 +45,18 @@ func CrossBuild() error {
 	return mage.CrossBuild()
 }
 
-// Fields generates a fields.yml and fields.go for each module.
+// Fields generates the fields.yml file and a fields.go for each module and
+// input.
 func Fields() {
-	mg.Deps(fieldsYML, mage.GenerateModuleFieldsGo)
+	mg.Deps(fieldsYML, moduleFieldsGo, inputFieldsGo)
+}
+
+func inputFieldsGo() error {
+	return mage.GenerateModuleFieldsGo("input")
+}
+
+func moduleFieldsGo() error {
+	return mage.GenerateModuleFieldsGo("module")
 }
 
 // fieldsYML generates a fields.yml based on filebeat + x-pack/filebeat/modules.
@@ -65,9 +74,13 @@ func Config() {
 	mg.Deps(shortConfig, referenceConfig, createDirModulesD)
 }
 
-// Update is an alias for running fields, dashboards, config.
+// Update is an alias for executing fields, dashboards, config.
 func Update() {
-	mg.SerialDeps(Fields, Dashboards, Config)
+	mg.SerialDeps(Fields, Dashboards, Config, includeList)
+}
+
+func includeList() error {
+	return mage.GenerateIncludeListGo([]string{"input/*"}, []string{"module"})
 }
 
 // UnitTest executes the unit tests.