Remove Beat generators (#28816)

From 8.0.0, we no longer support building custom Beats. This removes the documentation and the code as well.

If someone wants to build their custom Beats, they still can based on 7.16.

CHANGELOG-developer.next.asciidoc

@@ -56,6 +56,7 @@ The list below covers the major changes between 7.0.0-rc2 and master only.
 - Remove Metricbeat EventFetcher and EventsFetcher interface. Use the reporter interface instead. {pull}25093[25093]
 - Update Darwin build image to a debian 10 base that increases the MacOS SDK and minimum supported version used in build to 10.14. {issue}24193[24193]
 - Removed the `common.Float` type. {issue}28279[28279] {pull}28280[28280] {pull}28376[28376]
+- Removed Beat generators. {pull}28816[28816]
 - libbeat.logp package forces ECS compliant logs. Logs are JSON formatted. Options to enable ECS/JSON have been removed. {issue}15544[15544] {pull}28573[28573]
 
 ==== Bugfixes

Jenkinsfile.yml

@@ -2,8 +2,6 @@ projects:
     - "auditbeat"
     - "deploy/kubernetes"
     - "filebeat"
-    # Skipping because they are failing, see https://github.com/elastic/beats/pull/28723
-    #- "generator"
     - "heartbeat"
     - "libbeat"
     - "metricbeat"

dev-tools/mage/fmt.go

@@ -50,13 +50,10 @@ func Format() {
 	mg.Deps(GoImports, PythonAutopep8)
 }
 
-// GoImports executes goimports against all .go files in and below the CWD. It
-// ignores vendor/ and generator/_templates/ directories.
+// GoImports executes goimports against all .go files in and below the CWD.
 func GoImports() error {
 	goFiles, err := FindFilesRecursive(func(path string, _ os.FileInfo) bool {
-		return filepath.Ext(path) == ".go" &&
-			!strings.Contains(path, "vendor/") &&
-			!strings.Contains(path, "generator/_templates/")
+		return filepath.Ext(path) == ".go"
 	})
 	if err != nil {
 		return err
@@ -84,9 +81,7 @@ func GoImports() error {
 // ignores build/ directories.
 func PythonAutopep8() error {
 	pyFiles, err := FindFilesRecursive(func(path string, _ os.FileInfo) bool {
-		return filepath.Ext(path) == ".py" &&
-			!strings.Contains(path, "build/") &&
-			!strings.Contains(path, "vendor/")
+		return filepath.Ext(path) == ".py" && !strings.Contains(path, "build/")
 	})
 	if err != nil {
 		return err

docs/devguide/contributing.asciidoc

@@ -35,17 +35,6 @@ In the pull request, describe what your changes do and mention
 any bugs/issues related to the pull request. Please also add a changelog entry to
 https://github.com/elastic/beats/blob/master/CHANGELOG.next.asciidoc[CHANGELOG.next.asciidoc].
 
-[float]
-[[adding-new-beat]]
-=== Adding a New Beat
-
-If you want to create a new Beat, please read <<new-beat>>. You don't need to
-submit the code to this repository. Most new Beats start in their own repository
-and just make use of the libbeat packages. After you have a working Beat that
-you'd like to share with others, open a PR to add it to our list of
-https://github.com/elastic/beats/blob/master/libbeat/docs/communitybeats.asciidoc[community
-Beats].
-
 [float]
 [[setting-up-dev-environment]]
 === Setting Up Your Dev Environment

docs/devguide/create-metricset.asciidoc

@@ -2,8 +2,7 @@
 === Creating a Metricset
 
 A metricset is the part of a Metricbeat module that fetches and structures the
-data from the remote service. Each module can have multiple metricsets. In this guide, you learn how to create your own metricset. If you want to create
-your own Beat that uses Metricbeat as a library, see <<creating-beat-from-metricbeat>>.
+data from the remote service. Each module can have multiple metricsets. In this guide, you learn how to create your own metricset.
 
 When creating a metricset for the first time, it generally helps to look at the
 implementation of existing metricsets for inspiration.

docs/devguide/index.asciidoc

@@ -21,8 +21,6 @@ include::./contributing.asciidoc[]
 
 include::{libbeat-dir}/communitybeats.asciidoc[]
 
-include::./newbeat.asciidoc[]
-
 include::./fields-yml.asciidoc[]
 
 include::./event-conventions.asciidoc[]

docs/devguide/metricbeat-devguide.asciidoc

@@ -18,7 +18,6 @@ This following topics describe how to contribute to Metricbeat by adding metrics
 * <<creating-metricsets>>
 * <<metricset-details>>
 * <<creating-metricbeat-module>>
-* <<creating-beat-from-metricbeat>>
 * <<dev-faq>>
 
 If you would like to contribute to Metricbeat or the Beats project, also see
@@ -59,6 +58,4 @@ include::./metricset-details.asciidoc[]
 
 include::./create-module.asciidoc[]
 
-include::./creating-beat-from-metricbeat.asciidoc[]
-
 include::./faq.asciidoc[]