From e2d448eb73dece18a2969ba66873e1c93f30e5fb Mon Sep 17 00:00:00 2001
From: Pier-Hugues Pellerin <phpellerin@gmail.com>
Date: Fri, 2 Nov 2018 08:20:04 -0400
Subject: [PATCH] Make functionbeat build process depends on linux/amd64
 (#8889)

Functionbeat packaging depends on a Linux binary that will be sent to
the serverless platform, previously the magefile for the project did not express
that dependency. This was causing problems when you were building the
packages only for a specific platform. This commit fixes that problem by
introducing `mage.WithPlatforms` this allows you to specific dependency
when you define the cross build logic.
---
 CHANGELOG-developer.asciidoc    |  1 +
 dev-tools/mage/crossbuild.go    | 11 +++++++++++
 dev-tools/mage/platforms.go     |  8 ++++++++
 x-pack/functionbeat/magefile.go |  2 +-
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG-developer.asciidoc b/CHANGELOG-developer.asciidoc
index 0e99f83776e..ba7602a75f1 100644
--- a/CHANGELOG-developer.asciidoc
+++ b/CHANGELOG-developer.asciidoc
@@ -62,3 +62,4 @@ The list below covers the major changes between 6.3.0 and master only.
 - Add `mage.GenerateFieldsGo` for generating fields.go files. {pull}8615[8615]
 - Add `mage.KibanaDashboards` for collecting Kibana dashboards and generating index patterns. {pull}8615[8615]
 - Allow to disable config resolver using the `Settings.DisableConfigResolver` field when initializing libbeat. {pull}8769[8769]
+- Add `mage.AddPlatforms` to allow to specify dependent platforms when building a beat. {pull}8889[8889]
diff --git a/dev-tools/mage/crossbuild.go b/dev-tools/mage/crossbuild.go
index c75bb57ec57..92bf6bc4439 100644
--- a/dev-tools/mage/crossbuild.go
+++ b/dev-tools/mage/crossbuild.go
@@ -88,6 +88,17 @@ func ImageSelector(f ImageSelectorFunc) func(params *crossBuildParams) {
 	}
 }
 
+// AddPlatforms sets dependencies on others platforms.
+func AddPlatforms(expressions ...string) func(params *crossBuildParams) {
+	return func(params *crossBuildParams) {
+		var list BuildPlatformList
+		for _, expr := range expressions {
+			list = NewPlatformList(expr)
+			params.Platforms = params.Platforms.Merge(list)
+		}
+	}
+}
+
 type crossBuildParams struct {
 	Platforms     BuildPlatformList
 	Target        string
diff --git a/dev-tools/mage/platforms.go b/dev-tools/mage/platforms.go
index c6039c55aba..8dbfc1c7b82 100644
--- a/dev-tools/mage/platforms.go
+++ b/dev-tools/mage/platforms.go
@@ -445,6 +445,14 @@ func (list BuildPlatformList) Filter(expr string) BuildPlatformList {
 	return out.deduplicate()
 }
 
+// Merge creates a new list with the two list merged.
+func (list BuildPlatformList) Merge(with BuildPlatformList) BuildPlatformList {
+	out := make(BuildPlatformList, 0, len(list)+len(with))
+	out = append(list, with...)
+	out = append(out, with...)
+	return out.deduplicate()
+}
+
 // deduplicate removes duplicate platforms and sorts the list.
 func (list BuildPlatformList) deduplicate() BuildPlatformList {
 	set := map[string]BuildPlatform{}
diff --git a/x-pack/functionbeat/magefile.go b/x-pack/functionbeat/magefile.go
index e6d2b416a5a..d379baeb734 100644
--- a/x-pack/functionbeat/magefile.go
+++ b/x-pack/functionbeat/magefile.go
@@ -39,7 +39,7 @@ func BuildGoDaemon() error {
 
 // CrossBuild cross-builds the beat for all target platforms.
 func CrossBuild() error {
-	return mage.CrossBuild()
+	return mage.CrossBuild(mage.AddPlatforms("linux/amd64"))
 }
 
 // CrossBuildGoDaemon cross-builds the go-daemon binary using Docker.