Assert now takes into consideration the license. (elastic#7855)

- License headers for both Elastic and ASL2 are now accessible by
  code using the licenses package.
      ```
      licenses.Elastic
      licenses.ASL2
      ```
  - Added a generator to take care of syncing the files in the licenses/
  directory.
  - Added `LICENSE` as a variable for the makefile to configure the
  go-licenser this is useful if a beat as a different license.

dev-tools/cmd/asset/asset.go

@@ -29,18 +29,21 @@ import (
 	"os"
 
 	"github.com/elastic/beats/libbeat/asset"
+	"github.com/elastic/beats/licenses"
 )
 
 var (
-	pkg    string
-	input  string
-	output string
+	pkg     string
+	input   string
+	output  string
+	license = "ASL2"
 )
 
 func init() {
 	flag.StringVar(&pkg, "pkg", "", "Package name")
 	flag.StringVar(&input, "in", "-", "Source of input. \"-\" means reading from stdin")
 	flag.StringVar(&output, "out", "-", "Output path. \"-\" means writing to stdout")
+	flag.StringVar(&license, "license", "ASL2", "License header for generated file.")
 }
 
 func main() {
@@ -82,11 +85,17 @@ func main() {
 		os.Exit(1)
 	}
 
+	licenseHeader, err := licenses.Find(license)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Invalid license: %s\n", err)
+		os.Exit(1)
+	}
 	var buf bytes.Buffer
 	asset.Template.Execute(&buf, asset.Data{
 		Beat:    beatName,
 		Name:    file,
 		Data:    encData,
+		License: licenseHeader,
 		Package: pkg,
 	})
 

libbeat/scripts/Makefile

@@ -1,6 +1,7 @@
 ### VARIABLE SETUP ###
 ### Application using libbeat may override the following variables in their Makefile
 BEAT_NAME?=libbeat## @packaging Name of the binary
+LICENSE?=ASL2
 BEAT_TITLE?=${BEAT_NAME}## @packaging Title of the application
 BEAT_PATH?=github.com/elastic/beats/${BEAT_NAME}
 BEAT_PACKAGE_NAME?=${BEAT_NAME}
@@ -123,14 +124,14 @@ check: check-headers python-env prepare-tests ## @build Checks project and sourc
 check-headers:
 ifndef CHECK_HEADERS_DISABLED
 	@go get github.com/elastic/go-licenser
-	@go-licenser -d
+	@go-licenser -d -license ${LICENSE}
 endif
 
 .PHONY: add-headers
 add-headers:
 ifndef CHECK_HEADERS_DISABLED
 	@go get github.com/elastic/go-licenser
-	@go-licenser
+	@go-licenser -license ${LICENSE}
 endif
 
 .PHONY: fmt
@@ -332,7 +333,7 @@ endif
 
 ifneq ($(shell [[ $(BEAT_NAME) == libbeat || $(BEAT_NAME) == metricbeat ]] && echo true ),true)
 	mkdir -p include
-	go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -pkg include -in fields.yml -out include/fields.go $(BEAT_NAME) 
+	go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -pkg include -in fields.yml -out include/fields.go $(BEAT_NAME)
 endif
 
 ifneq ($(shell [[ $(BEAT_NAME) == libbeat ]] && echo true ),true)

licenses/APACHE-LICENSE-2.0-header.txt

@@ -0,0 +1,16 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.

licenses/ELASTIC-LICENSE-header.txt

@@ -0,0 +1,3 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.

licenses/license.go

@@ -0,0 +1,20 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package licenses
+
+//go:generate go run ../dev-tools/cmd/license/license_generate.go

metricbeat/Makefile

@@ -77,5 +77,5 @@ test-module: python-env update metricbeat.test
 assets:
 	go run ${ES_BEATS}/metricbeat/scripts/assets/assets.go ${ES_BEATS}/metricbeat/module
 	mkdir -p include/fields
-	go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -pkg include -in ${ES_BEATS}/metricbeat/_meta/fields.common.yml -out include/fields.go $(BEAT_NAME)
-	go run  ${ES_BEATS}/libbeat/scripts/cmd/global_fields/main.go -es_beats_path ${ES_BEATS} -beat_path ${PWD} | go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -out ./include/fields/fields.go -pkg include ${ES_BEATS}/libbeat/fields.yml $(BEAT_NAME)
+	go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -license ${LICENSE} -pkg include -in ${ES_BEATS}/metricbeat/_meta/fields.common.yml -out include/fields.go $(BEAT_NAME)
+	go run  ${ES_BEATS}/libbeat/scripts/cmd/global_fields/main.go -es_beats_path ${ES_BEATS} -beat_path ${PWD} | go run  ${ES_BEATS}/dev-tools/cmd/asset/asset.go -license ${LICENSE} -out ./include/fields/fields.go -pkg include ${ES_BEATS}/libbeat/fields.yml $(BEAT_NAME)

metricbeat/scripts/assets/assets.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/elastic/beats/libbeat/asset"
 	"github.com/elastic/beats/libbeat/generator/fields"
+	"github.com/elastic/beats/licenses"
 )
 
 func main() {
@@ -69,6 +70,7 @@ func main() {
 
 		var buf bytes.Buffer
 		asset.Template.Execute(&buf, asset.Data{
+			License: licenses.ASL2,
 			Beat:    "metricbeat",
 			Name:    module,
 			Data:    encData,