diff --git a/CHANGELOG-developer.asciidoc b/CHANGELOG-developer.asciidoc
index b47c53ca28a..cf844df59cf 100644
--- a/CHANGELOG-developer.asciidoc
+++ b/CHANGELOG-developer.asciidoc
@@ -25,6 +25,10 @@ The list below covers the major changes between 6.3.0 and master only.
 - Dashboards under _meta/kibana are expected to be decoded. See https://github.com/elastic/beats/pull/7224 for a conversion script. {pull}7265[7265]
 - Constructor `(github.com/elastic/beats/libbeat/output/codec/json).New` expects a new `escapeHTML` parameter. {pull}7445[7445]
 - Packaging has been refactored and updates are required. See the PR for migration details. {pull}7388[7388]
+- `make fields` has been modified to use Mage (https://magefile.org/) in an effort to make
+  the building a Beat more cross-platform friendly (e.g. Windows). This requires that your Beat
+  has a magefile.go with a fields target. The `FIELDS_FILE_PATH` make variable is no longer
+  used because the value is specified in magefile.go. {pull}7670[7670]
 
 ==== Bugfixes
 
diff --git a/auditbeat/Makefile b/auditbeat/Makefile
index 36c51fbf0e6..08c0d4be4b7 100644
--- a/auditbeat/Makefile
+++ b/auditbeat/Makefile
@@ -6,7 +6,6 @@ GOX_OS?=linux windows ## @Building List of all OS to be supported by "make cross
 DEV_OS?=linux
 TESTING_ENVIRONMENT?=snapshot-noxpack
 ES_BEATS?=..
-FIELDS_FILE_PATH=module
 
 # Path to the libbeat Makefile
 include ${ES_BEATS}/libbeat/scripts/Makefile
diff --git a/auditbeat/magefile.go b/auditbeat/magefile.go
index 234afa2449f..0b45a4e52c6 100644
--- a/auditbeat/magefile.go
+++ b/auditbeat/magefile.go
@@ -91,6 +91,11 @@ func Update() error {
 	return sh.Run("make", "update")
 }
 
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("module")
+}
+
 // -----------------------------------------------------------------------------
 // Customizations specific to Auditbeat.
 // - Config files are Go templates.
diff --git a/auditbeat/make.bat b/auditbeat/make.bat
new file mode 100644
index 00000000000..81de1ba946f
--- /dev/null
+++ b/auditbeat/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/dev-tools/jenkins_ci.ps1 b/dev-tools/jenkins_ci.ps1
index a27381a36e9..39abe9fad17 100755
--- a/dev-tools/jenkins_ci.ps1
+++ b/dev-tools/jenkins_ci.ps1
@@ -21,6 +21,14 @@ $env:PATH = "$env:GOPATH\bin;C:\tools\mingw64\bin;$env:PATH"
 # each run starts from a clean slate.
 $env:MAGEFILE_CACHE = "$env:WORKSPACE\.magefile"
 
+exec { go install github.com/elastic/beats/vendor/github.com/magefile/mage }
+exec { go get -u github.com/jstemmer/go-junit-report }
+
+echo "Building libbeat fields.yml"
+cd libbeat
+exec { mage fields }
+cd ..
+
 if (Test-Path "$env:beat") {
     cd "$env:beat"
 } else {
@@ -35,20 +43,11 @@ New-Item -ItemType directory -Path build\coverage | Out-Null
 New-Item -ItemType directory -Path build\system-tests | Out-Null
 New-Item -ItemType directory -Path build\system-tests\run | Out-Null
 
-exec { go get -u github.com/jstemmer/go-junit-report }
+echo "Building fields.yml"
+exec { mage fields }
 
 echo "Building $env:beat"
-exec { go build } "Build FAILURE"
-
-# always build the libbeat fields
-cp ..\libbeat\_meta\fields.common.yml ..\libbeat\_meta\fields.generated.yml
-cat ..\libbeat\processors\*\_meta\fields.yml | Out-File -append -encoding UTF8 -filepath ..\libbeat\_meta\fields.generated.yml
-cp ..\libbeat\_meta\fields.generated.yml ..\libbeat\fields.yml
-
-if ($env:beat -eq "metricbeat") {
-    cp .\_meta\fields.common.yml .\_meta\fields.generated.yml
-    python .\scripts\fields_collector.py | out-file -append -encoding UTF8 -filepath .\_meta\fields.generated.yml
-}
+exec { mage build } "Build FAILURE"
 
 echo "Unit testing $env:beat"
 go test -v $(go list ./... | select-string -Pattern "vendor" -NotMatch) 2>&1 | Out-File -encoding UTF8 build/TEST-go-unit.out
diff --git a/dev-tools/mage/fields.go b/dev-tools/mage/fields.go
new file mode 100644
index 00000000000..8f658483ffb
--- /dev/null
+++ b/dev-tools/mage/fields.go
@@ -0,0 +1,48 @@
+// 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 mage
+
+import (
+	"path/filepath"
+
+	"github.com/magefile/mage/sh"
+)
+
+// GenerateFieldsYAML generates a fields.yml file for a Beat. This will include
+// the common fields specified by libbeat, the common fields for the Beat,
+// and any additional fields.yml files you specify.
+//
+// fieldsFiles specifies additional directories to search recursively for files
+// named fields.yml. The contents of each fields.yml will be included in the
+// generated file.
+func GenerateFieldsYAML(fieldsFiles ...string) error {
+	const globalFieldsCmdPath = "libbeat/scripts/cmd/global_fields/main.go"
+
+	beatsDir, err := ElasticBeatsDir()
+	if err != nil {
+		return err
+	}
+
+	globalFieldsCmd := sh.RunCmd("go", "run",
+		filepath.Join(beatsDir, globalFieldsCmdPath),
+		"-es_beats_path", beatsDir,
+		"-beat_path", CWD(),
+	)
+
+	return globalFieldsCmd(fieldsFiles...)
+}
diff --git a/dev-tools/packaging/templates/common/magefile.go.tmpl b/dev-tools/packaging/templates/common/magefile.go.tmpl
index 1a9822d2491..db7f7132110 100644
--- a/dev-tools/packaging/templates/common/magefile.go.tmpl
+++ b/dev-tools/packaging/templates/common/magefile.go.tmpl
@@ -70,3 +70,8 @@ func TestPackages() error {
 func Update() error {
 	return sh.Run("make", "update")
 }
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("protos")
+}
diff --git a/filebeat/magefile.go b/filebeat/magefile.go
index 8feb27a6908..41cb9ce9014 100644
--- a/filebeat/magefile.go
+++ b/filebeat/magefile.go
@@ -91,6 +91,11 @@ func Update() error {
 	return sh.Run("make", "update")
 }
 
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("module")
+}
+
 // -----------------------------------------------------------------------------
 // Customizations specific to Filebeat.
 // - Include modules directory in packages (minus _meta and test files).
diff --git a/filebeat/make.bat b/filebeat/make.bat
index 3f92e367f42..81de1ba946f 100644
--- a/filebeat/make.bat
+++ b/filebeat/make.bat
@@ -1,7 +1,11 @@
-REM Batch script to build and test on Windows. You can use this in conjunction
-REM with the Vagrant machine.
-go build
-go test ./...
-go test -c -cover -covermode=count -coverpkg ./...
-cd tests\system
-nosetests
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/generator/beat/Makefile b/generator/beat/Makefile
index 0e5913ea44d..dd1e5be8557 100644
--- a/generator/beat/Makefile
+++ b/generator/beat/Makefile
@@ -1,4 +1 @@
-override FIELDS_FILE_PATH=
-export FIELDS_FILE_PATH
-
 include ../common/Makefile
diff --git a/generator/beat/{beat}/Makefile b/generator/beat/{beat}/Makefile
index e96c81728f1..8fdde0a7e0c 100644
--- a/generator/beat/{beat}/Makefile
+++ b/generator/beat/{beat}/Makefile
@@ -13,7 +13,7 @@ MAGE_IMPORT_PATH=${BEAT_PATH}/vendor/github.com/magefile/mage
 
 # Initial beat setup
 .PHONY: setup
-setup: copy-vendor update git-init
+setup: copy-vendor git-init update git-add
 
 # Copy beats into vendor directory
 .PHONY: copy-vendor
@@ -27,17 +27,11 @@ copy-vendor:
 .PHONY: git-init
 git-init:
 	git init
-	git add README.md CONTRIBUTING.md
-	git commit -m "Initial commit"
-	git add LICENSE.txt
-	git commit -m "Add the LICENSE"
-	git add .gitignore
-	git commit -m "Add git settings"
-	git add .
-	git reset -- .travis.yml
-	git commit -m "Add {beat}"
-	git add .travis.yml
-	git commit -m "Add Travis CI"
+
+.PHONY: git-add
+git-add:
+	git add -A
+	git commit -m "Add generated {beat} files"
 
 # Collects all dependencies and then calls update
 .PHONY: collect
diff --git a/generator/beat/{beat}/magefile.go b/generator/beat/{beat}/magefile.go
index 545af4c3d10..13c6184b5fa 100644
--- a/generator/beat/{beat}/magefile.go
+++ b/generator/beat/{beat}/magefile.go
@@ -89,3 +89,8 @@ func TestPackages() error {
 func Update() error {
 	return sh.Run("make", "update")
 }
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML()
+}
diff --git a/generator/beat/{beat}/make.bat b/generator/beat/{beat}/make.bat
new file mode 100644
index 00000000000..72de5798dfa
--- /dev/null
+++ b/generator/beat/{beat}/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install {beat_path}/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/generator/common/Makefile b/generator/common/Makefile
index 248b6c7119c..8ad037be6e0 100644
--- a/generator/common/Makefile
+++ b/generator/common/Makefile
@@ -11,23 +11,36 @@ PREPARE_COMMAND?=
 test: prepare-test
 	. ${PYTHON_ENV}/bin/activate; \
 	export GOPATH=${PWD}/build ; \
-	export PATH=${PATH}:${PWD}/build/bin; \
+	export PATH=$${GOPATH}/bin:${PATH}; \
 	cd ${BEAT_PATH} ; \
 	$(MAKE) copy-vendor || exit 1  ; \
 	${PREPARE_COMMAND} \
+	$(MAKE) git-init || exit 1 ; \
 	$(MAKE) update || exit 1 ; \
+	$(MAKE) git-add || exit 1 ; \
 	$(MAKE) check CHECK_HEADERS_DISABLED=y || exit 1 ; \
 	$(MAKE) || exit 1 ; \
 	$(MAKE) unit
 
+.PHONY: prepare-test
 prepare-test:: python-env
 	# Makes sure to use current version of beats for testing
 	mkdir -p ${BUILD_DIR}/src/github.com/elastic/beats/
-	rsync -a --exclude=build ${PWD}/../../* ${BUILD_DIR}/src/github.com/elastic/beats/
+	rsync -a \
+	  --include=vendor/github.com/magefile/mage/build \
+	  --exclude=build/ \
+	  --exclude=.git/ \
+	  ${PWD}/../../* ${BUILD_DIR}/src/github.com/elastic/beats/
 
 	mkdir -p ${BEAT_PATH}
 	export GOPATH=${PWD}/build ; \
-	. ${PYTHON_ENV}/bin/activate && python ${PWD}/build/src/github.com/elastic/beats/script/generate.py --type=${BEAT_TYPE} --project_name=Testbeat --github_name=ruflin --beat_path=beatpath/testbeat --full_name="Nicolas Ruflin"
+	. ${PYTHON_ENV}/bin/activate && \
+	  python ${PWD}/build/src/github.com/elastic/beats/script/generate.py \
+	    --type=${BEAT_TYPE} \
+	    --project_name=Testbeat \
+	    --github_name=ruflin \
+	    --beat_path=beatpath/testbeat \
+	    --full_name="Nicolas Ruflin"
 
 # Runs test build for the created beat
 .PHONY: test-build
diff --git a/generator/metricbeat/Makefile b/generator/metricbeat/Makefile
index 11203d15e0f..f91acb876a3 100644
--- a/generator/metricbeat/Makefile
+++ b/generator/metricbeat/Makefile
@@ -1,16 +1,14 @@
-BEAT_TYPE=metricbeat
-PREPARE_COMMAND=MODULE=elastic METRICSET=test make create-metricset ; FIELDS_FILE_PATH=module
-override FIELDS_FILE_PATH=
-export FIELDS_FILE_PATH
-
+BEAT_TYPE       = metricbeat
+PREPARE_COMMAND = MODULE=elastic METRICSET=test make create-metricset;
 
 include ../common/Makefile
 
+.PHONY: prepare-test
 prepare-test:: python-env
-
 	mkdir -p ${BEAT_PATH}/scripts
 	rsync -a --exclude=build ${PWD}/../../metricbeat/scripts/generate_imports_helper.py ${BEAT_PATH}/scripts
 
 # Collects all dependencies and then calls update
 .PHONY: collect
 collect: fields
+
diff --git a/generator/metricbeat/{beat}/Makefile b/generator/metricbeat/{beat}/Makefile
index 9882c9783f0..478a3f7a4e1 100644
--- a/generator/metricbeat/{beat}/Makefile
+++ b/generator/metricbeat/{beat}/Makefile
@@ -13,7 +13,7 @@ MAGE_IMPORT_PATH=${BEAT_PATH}/vendor/github.com/magefile/mage
 
 # Initial beat setup
 .PHONY: setup
-setup: copy-vendor create-metricset collect git-init
+setup: copy-vendor git-init create-metricset collect git-add
 
 # Copy beats into vendor directory
 .PHONY: copy-vendor
@@ -28,5 +28,8 @@ copy-vendor:
 .PHONY: git-init
 git-init:
 	git init
-	git add --all
-	git commit -m 'Initial add by Beat generator'
+
+.PHONY: git-add
+git-add:
+	git add -A
+	git commit -m "Add generated {beat} files"
diff --git a/generator/metricbeat/{beat}/magefile.go b/generator/metricbeat/{beat}/magefile.go
index 545af4c3d10..fa75eff3a80 100644
--- a/generator/metricbeat/{beat}/magefile.go
+++ b/generator/metricbeat/{beat}/magefile.go
@@ -89,3 +89,8 @@ func TestPackages() error {
 func Update() error {
 	return sh.Run("make", "update")
 }
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("module")
+}
diff --git a/generator/metricbeat/{beat}/make.bat b/generator/metricbeat/{beat}/make.bat
new file mode 100644
index 00000000000..72de5798dfa
--- /dev/null
+++ b/generator/metricbeat/{beat}/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install {beat_path}/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/heartbeat/Makefile b/heartbeat/Makefile
index 16053181ce5..498c10747b5 100644
--- a/heartbeat/Makefile
+++ b/heartbeat/Makefile
@@ -2,7 +2,6 @@ BEAT_NAME=heartbeat
 BEAT_TITLE=Heartbeat
 SYSTEM_TESTS=true
 TEST_ENVIRONMENT=false
-FIELDS_FILE_PATH=monitors/active
 
 # Path to the libbeat Makefile
 -include ../libbeat/scripts/Makefile
diff --git a/heartbeat/magefile.go b/heartbeat/magefile.go
index f52d0935da9..a23b8687e00 100644
--- a/heartbeat/magefile.go
+++ b/heartbeat/magefile.go
@@ -88,3 +88,8 @@ func TestPackages() error {
 func Update() error {
 	return sh.Run("make", "update")
 }
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("monitors/active")
+}
diff --git a/heartbeat/make.bat b/heartbeat/make.bat
new file mode 100644
index 00000000000..81de1ba946f
--- /dev/null
+++ b/heartbeat/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/libbeat/Makefile b/libbeat/Makefile
index d63820feabc..93b34f77104 100644
--- a/libbeat/Makefile
+++ b/libbeat/Makefile
@@ -1,7 +1,6 @@
 BEAT_NAME=libbeat
 TEST_ENVIRONMENT?=true
 SYSTEM_TESTS=true
-FIELDS_FILE_PATH=processors
 
 include scripts/Makefile
 
diff --git a/libbeat/generator/fields/fields.go b/libbeat/generator/fields/fields.go
index 68365dced93..02ec5374948 100644
--- a/libbeat/generator/fields/fields.go
+++ b/libbeat/generator/fields/fields.go
@@ -20,12 +20,13 @@ package fields
 import (
 	"bufio"
 	"bytes"
-	"fmt"
 	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 var (
@@ -152,7 +153,7 @@ func createIfNotExists(inPath, outPath string) error {
 	if os.IsNotExist(err) {
 		err := copyFileWithFlag(inPath, outPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC)
 		if err != nil {
-			fmt.Println("Cannot find _meta/fields.yml")
+			return err
 		}
 		return nil
 	}
@@ -162,12 +163,17 @@ func createIfNotExists(inPath, outPath string) error {
 func copyFileWithFlag(in, out string, flag int) error {
 	input, err := ioutil.ReadFile(in)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to read source in copy")
+	}
+
+	if err := os.MkdirAll(filepath.Dir(out), 0755); err != nil {
+		return errors.Wrapf(err, "failed to create destination dir for copy "+
+			"at %v", filepath.Dir(out))
 	}
 
 	output, err := os.OpenFile(out, flag, 0644)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to open destination file for copy")
 	}
 	defer output.Close()
 
diff --git a/libbeat/magefile.go b/libbeat/magefile.go
new file mode 100644
index 00000000000..939eac4adb0
--- /dev/null
+++ b/libbeat/magefile.go
@@ -0,0 +1,39 @@
+// 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.
+
+// +build mage
+
+package main
+
+import (
+	"github.com/elastic/beats/dev-tools/mage"
+)
+
+// Build builds the Beat binary.
+func Build() error {
+	return mage.Build(mage.DefaultBuildArgs())
+}
+
+// Clean cleans all generated files and build artifacts.
+func Clean() error {
+	return mage.Clean()
+}
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("processors")
+}
diff --git a/libbeat/make.bat b/libbeat/make.bat
new file mode 100644
index 00000000000..81de1ba946f
--- /dev/null
+++ b/libbeat/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/libbeat/scripts/Makefile b/libbeat/scripts/Makefile
index d2b109cbcbb..8e8a0ac3887 100755
--- a/libbeat/scripts/Makefile
+++ b/libbeat/scripts/Makefile
@@ -20,7 +20,9 @@ ELASTIC_LICENSE_FILE?=../licenses/ELASTIC-LICENSE.txt
 SECCOMP_BINARY?=${BEAT_NAME}
 SECCOMP_BLACKLIST?=${ES_BEATS}/libbeat/common/seccomp/seccomp-profiler-blacklist.txt
 SECCOMP_ALLOWLIST?=${ES_BEATS}/libbeat/common/seccomp/seccomp-profiler-allow.txt
+MAGE_PRESENT := $(shell command -v mage 2> /dev/null)
 MAGE_IMPORT_PATH?=github.com/elastic/beats/vendor/github.com/magefile/mage
+export MAGE_IMPORT_PATH
 
 space:=$() #
 comma:=,
@@ -304,9 +306,8 @@ coverage-report:
 
 
 .PHONY: fields
-fields:
-	@go run ${ES_BEATS}/libbeat/scripts/cmd/global_fields/main.go --es_beats_path $(ES_BEATS) --beat_path $(PWD) $(FIELDS_FILE_PATH)
-
+fields: mage
+	mage -v fields
 
 .PHONY: libbeat_fields
 libbeat_fields:
@@ -442,7 +443,9 @@ seccomp-package:
 
 .PHONY: mage
 mage:
-	@go install ${MAGE_IMPORT_PATH}
+ifndef MAGE_PRESENT
+	go install ${MAGE_IMPORT_PATH}
+endif
 
 .PHONY: release
 release: mage
diff --git a/libbeat/scripts/cmd/global_fields/main.go b/libbeat/scripts/cmd/global_fields/main.go
index 8bd5b691506..74fc94a603d 100644
--- a/libbeat/scripts/cmd/global_fields/main.go
+++ b/libbeat/scripts/cmd/global_fields/main.go
@@ -31,41 +31,46 @@ func main() {
 	beatPath := flag.String("beat_path", ".", "Path to your Beat")
 	flag.Parse()
 
-	beatFieldsPath := flag.Args()
+	beatFieldsPaths := flag.Args()
 	name := filepath.Base(*beatPath)
 
-	err := os.MkdirAll(filepath.Join(*beatPath, "_meta"), 0744)
+	if *beatPath == "" {
+		fmt.Fprintf(os.Stderr, "beat_path cannot be empty")
+		os.Exit(1)
+	}
+
+	err := os.MkdirAll(filepath.Join(*beatPath, "_meta"), 0755)
 	if err != nil {
-		fmt.Printf("Cannot create _meta dir for %s: %v\n", name, err)
+		fmt.Fprintf(os.Stderr, "Cannot create _meta dir for %s: %+v\n", name, err)
 		os.Exit(1)
 	}
 
-	if len(beatFieldsPath) == 0 {
+	if len(beatFieldsPaths) == 0 {
 		fmt.Println("No field files to collect")
 		err = fields.AppendFromLibbeat(*esBeatsPath, *beatPath)
 		if err != nil {
-			fmt.Printf("Cannot generate global fields.yml for %s: %v\n", name, err)
+			fmt.Fprintf(os.Stderr, "Cannot generate global fields.yml for %s: %+v\n", name, err)
 			os.Exit(2)
 		}
 		return
 	}
 
-	if *beatPath == "" {
-		fmt.Println("beat_path cannot be empty")
-		os.Exit(1)
-	}
+	var fieldsFiles []*fields.YmlFile
+	for _, fieldsFilePath := range beatFieldsPaths {
+		pathToModules := filepath.Join(*beatPath, fieldsFilePath)
 
-	pathToModules := filepath.Join(*beatPath, beatFieldsPath[0])
-	fieldFiles, err := fields.CollectModuleFiles(pathToModules)
-	if err != nil {
-		fmt.Printf("Cannot collect fields.yml files: %v\n", err)
-		os.Exit(2)
+		fieldsFile, err := fields.CollectModuleFiles(pathToModules)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Cannot collect fields.yml files: %+v\n", err)
+			os.Exit(2)
+		}
 
+		fieldsFiles = append(fieldsFiles, fieldsFile...)
 	}
 
-	err = fields.Generate(*esBeatsPath, *beatPath, fieldFiles)
+	err = fields.Generate(*esBeatsPath, *beatPath, fieldsFiles)
 	if err != nil {
-		fmt.Printf("Cannot generate global fields.yml file for %s: %v\n", name, err)
+		fmt.Fprintf(os.Stderr, "Cannot generate global fields.yml file for %s: %+v\n", name, err)
 		os.Exit(3)
 	}
 
diff --git a/make.bat b/make.bat
new file mode 100644
index 00000000000..81de1ba946f
--- /dev/null
+++ b/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/metricbeat/Makefile b/metricbeat/Makefile
index a055c1a6f04..f42f8cca6f4 100644
--- a/metricbeat/Makefile
+++ b/metricbeat/Makefile
@@ -4,7 +4,6 @@ BEAT_TITLE?=Metricbeat
 SYSTEM_TESTS?=true
 TEST_ENVIRONMENT?=true
 ES_BEATS?=..
-FIELDS_FILE_PATH?=module
 
 # Metricbeat can only be cross-compiled on platforms not requiring CGO.
 GOX_OS=netbsd linux windows
diff --git a/metricbeat/magefile.go b/metricbeat/magefile.go
index 02f9bbe516c..c19cbf578a9 100644
--- a/metricbeat/magefile.go
+++ b/metricbeat/magefile.go
@@ -91,6 +91,11 @@ func Update() error {
 	return sh.Run("make", "update")
 }
 
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("module")
+}
+
 // -----------------------------------------------------------------------------
 // Customizations specific to Metricbeat.
 // - Include modules.d directory in packages.
diff --git a/metricbeat/make.bat b/metricbeat/make.bat
index 7edecf7aaca..81de1ba946f 100644
--- a/metricbeat/make.bat
+++ b/metricbeat/make.bat
@@ -1,34 +1,11 @@
 @echo off
 
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
 REM
-REM Batch script to build and test on Windows. You can use this in conjunction
-REM with the Vagrant machine.
-REM
-
-go install github.com/elastic/beats/vendor/github.com/pierrre/gotestcover
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo Building
-go build
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo Testing
-mkdir build\coverage
-gotestcover -race -coverprofile=build/coverage/integration.cov github.com/elastic/beats/metricbeat/...
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo System Testing
-go test -c -covermode=atomic -coverpkg ./...
-if %errorlevel% neq 0 exit /b %errorlevel%
-nosetests -v -w tests\system --process-timeout=30
-if %errorlevel% neq 0 exit /b %errorlevel%
+REM After running this once you may invoke mage.exe directly.
 
-echo Aggregating Coverage Reports
-python ..\dev-tools\aggregate_coverage.py -o build\coverage\system.cov .\build\system-tests\run
-if %errorlevel% neq 0 exit /b %errorlevel%
-python ..\dev-tools\aggregate_coverage.py -o build\coverage\full.cov .\build\coverage
-if %errorlevel% neq 0 exit /b %errorlevel%
-go tool cover -html=build\coverage\full.cov -o build\coverage\full.html
-if %errorlevel% neq 0 exit /b %errorlevel%
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
 
-echo Success
+mage %*
diff --git a/packetbeat/Makefile b/packetbeat/Makefile
index 7c0b5325834..03ed18219db 100644
--- a/packetbeat/Makefile
+++ b/packetbeat/Makefile
@@ -3,7 +3,6 @@ BEAT_TITLE?=Packetbeat
 SYSTEM_TESTS?=true
 TEST_ENVIRONMENT=false
 ES_BEATS?=..
-FIELDS_FILE_PATH=protos
 
 include ${ES_BEATS}/libbeat/scripts/Makefile
 
diff --git a/packetbeat/magefile.go b/packetbeat/magefile.go
index 98c37ea5167..b002c88e69d 100644
--- a/packetbeat/magefile.go
+++ b/packetbeat/magefile.go
@@ -118,6 +118,11 @@ func Update() error {
 	return sh.Run("make", "update")
 }
 
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML("protos")
+}
+
 // -----------------------------------------------------------------------------
 // Customizations specific to Packetbeat.
 // - Config file contains an OS specific device name (affects darwin, windows).
diff --git a/packetbeat/make.bat b/packetbeat/make.bat
new file mode 100644
index 00000000000..81de1ba946f
--- /dev/null
+++ b/packetbeat/make.bat
@@ -0,0 +1,11 @@
+@echo off
+
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
+REM
+REM After running this once you may invoke mage.exe directly.
+
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
+
+mage %*
diff --git a/winlogbeat/magefile.go b/winlogbeat/magefile.go
index 5500f9fdca8..1d8ad837d83 100644
--- a/winlogbeat/magefile.go
+++ b/winlogbeat/magefile.go
@@ -88,3 +88,8 @@ func TestPackages() error {
 func Update() error {
 	return sh.Run("make", "update")
 }
+
+// Fields generates a fields.yml for the Beat.
+func Fields() error {
+	return mage.GenerateFieldsYAML()
+}
diff --git a/winlogbeat/make.bat b/winlogbeat/make.bat
index 0a46f8949b6..81de1ba946f 100644
--- a/winlogbeat/make.bat
+++ b/winlogbeat/make.bat
@@ -1,34 +1,11 @@
 @echo off
 
+REM Windows wrapper for Mage (https://magefile.org/) that installs it
+REM to %GOPATH%\bin from the Beats vendor directory.
 REM
-REM Batch script to build and test on Windows. You can use this in conjunction
-REM with the Vagrant machine.
-REM
-
-go install github.com/elastic/beats/vendor/github.com/pierrre/gotestcover
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo Building
-go build
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo Testing
-mkdir build\coverage
-gotestcover -race -coverprofile=build/coverage/integration.cov github.com/elastic/beats/winlogbeat/...
-if %errorlevel% neq 0 exit /b %errorlevel%
-
-echo System Testing
-go test -c -covermode=atomic -coverpkg ./...
-if %errorlevel% neq 0 exit /b %errorlevel%
-nosetests -v -w tests\system --process-timeout=30
-if %errorlevel% neq 0 exit /b %errorlevel%
+REM After running this once you may invoke mage.exe directly.
 
-echo Aggregating Coverage Reports
-python ..\dev-tools\aggregate_coverage.py -o build\coverage\system.cov .\build\system-tests\run
-if %errorlevel% neq 0 exit /b %errorlevel%
-python ..\dev-tools\aggregate_coverage.py -o build\coverage\full.cov .\build\coverage
-if %errorlevel% neq 0 exit /b %errorlevel%
-go tool cover -html=build\coverage\full.cov -o build\coverage\full.html
-if %errorlevel% neq 0 exit /b %errorlevel%
+WHERE mage
+IF %ERRORLEVEL% NEQ 0 go install github.com/elastic/beats/vendor/github.com/magefile/mage
 
-echo Success
+mage %*