From d9bc5b25fce92786dc52dbb670b88795c2b8068c Mon Sep 17 00:00:00 2001
From: Shirley Xiaolin Xu <xiaolin@hashicorp.com>
Date: Wed, 28 Jul 2021 15:19:54 -0700
Subject: [PATCH 1/4] add platform flag to build

---
 builtin/docker/builder.go                     | 19 ++++++++++++++++++-
 .../partials/components/builder-docker.mdx    |  9 +++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/builtin/docker/builder.go b/builtin/docker/builder.go
index fe302747c9a..500373fdfb8 100644
--- a/builtin/docker/builder.go
+++ b/builtin/docker/builder.go
@@ -55,6 +55,9 @@ type BuilderConfig struct {
 	// The name/path to the Dockerfile if it is not the root of the project
 	Dockerfile string `hcl:"dockerfile,optional"`
 
+	// Controls the passing of platform flag variables
+	Platform string `hcl:"platform,optional"`
+
 	// Controls the passing of build time variables
 	BuildArgs map[string]*string `hcl:"build_args,optional"`
 
@@ -138,6 +141,14 @@ build {
 		),
 	)
 
+	doc.SetField(
+		"platform",
+		"set platform if server is multi-platform capable",
+		docs.Summary(
+			"Recommended usage with buildkit enabled.",
+		),
+	)
+
 	doc.SetField(
 		"context",
 		"Build context path",
@@ -253,7 +264,7 @@ func (b *Builder) Build(
 		step.Done()
 		step = nil
 		if err := b.buildWithDocker(
-			ctx, ui, sg, cli, contextDir, relDockerfile, result.Name(), b.config.BuildArgs, log,
+			ctx, ui, sg, cli, contextDir, relDockerfile, result.Name(), b.config.Platform, b.config.BuildArgs, log,
 		); err != nil {
 			return nil, err
 		}
@@ -309,6 +320,7 @@ func (b *Builder) buildWithDocker(
 	contextDir string,
 	relDockerfile string,
 	tag string,
+	platform string,
 	buildArgs map[string]*string,
 	log hclog.Logger,
 ) error {
@@ -347,11 +359,16 @@ func (b *Builder) buildWithDocker(
 		return err
 	}
 
+	if platform != "" && ver != types.BuilderBuildKit {
+		return status.Errorf(codes.InvalidArgument, "buildkit is required to use platform option")
+	}
+
 	buildOpts := types.ImageBuildOptions{
 		Version:    ver,
 		Dockerfile: relDockerfile,
 		Tags:       []string{tag},
 		Remove:     true,
+		Platform:   platform,
 		BuildArgs:  buildArgs,
 	}
 
diff --git a/website/content/partials/components/builder-docker.mdx b/website/content/partials/components/builder-docker.mdx
index feb4a5876c6..06b8b8eb596 100644
--- a/website/content/partials/components/builder-docker.mdx
+++ b/website/content/partials/components/builder-docker.mdx
@@ -86,6 +86,15 @@ Set this when the Dockerfile is not APP-PATH/Dockerfile.
 - Type: **string**
 - **Optional**
 
+#### platform
+
+Set platform if server is multi-platform capable.
+
+Recommended usage with buildkit enabled.
+
+- Type: **string**
+- **Optional**
+
 ### Output Attributes
 
 Output attributes can be used in your `waypoint.hcl` as [variables](/docs/waypoint-hcl/variables) via [`artifact`](/docs/waypoint-hcl/variables/artifact) or [`deploy`](/docs/waypoint-hcl/variables/deploy).

From 670901a17e78932c8dff7279981f7fd2fc3c0824 Mon Sep 17 00:00:00 2001
From: Shirley Xiaolin Xu <xiaolin@hashicorp.com>
Date: Wed, 28 Jul 2021 15:38:49 -0700
Subject: [PATCH 2/4] changelog

---
 .changelog/1949.txt | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 .changelog/1949.txt

diff --git a/.changelog/1949.txt b/.changelog/1949.txt
new file mode 100644
index 00000000000..fb20ce048e5
--- /dev/null
+++ b/.changelog/1949.txt
@@ -0,0 +1,3 @@
+```release-note:feature
+plugin/docker: Enables image build for specified platform
+```

From 70ac5a924fa0c0b04ec772b975e3f8814f18faeb Mon Sep 17 00:00:00 2001
From: Shirley Xiaolin Xu <xiaolin@hashicorp.com>
Date: Mon, 2 Aug 2021 16:19:14 -0700
Subject: [PATCH 3/4] wording changes

---
 .changelog/1949.txt       | 2 +-
 builtin/docker/builder.go | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.changelog/1949.txt b/.changelog/1949.txt
index fb20ce048e5..4db19a37950 100644
--- a/.changelog/1949.txt
+++ b/.changelog/1949.txt
@@ -1,3 +1,3 @@
-```release-note:feature
+```release-note:improvement
 plugin/docker: Enables image build for specified platform
 ```
diff --git a/builtin/docker/builder.go b/builtin/docker/builder.go
index 500373fdfb8..eebbc86d90d 100644
--- a/builtin/docker/builder.go
+++ b/builtin/docker/builder.go
@@ -143,9 +143,9 @@ build {
 
 	doc.SetField(
 		"platform",
-		"set platform if server is multi-platform capable",
+		"set target platform to build container if server is multi-platform capable",
 		docs.Summary(
-			"Recommended usage with buildkit enabled.",
+			"Must enable Docker buildkit to use the 'platform' flag.",
 		),
 	)
 

From 7ca6b52e9913021034a07e744eda5e09315b6131 Mon Sep 17 00:00:00 2001
From: Shirley Xiaolin Xu <xiaolin@hashicorp.com>
Date: Tue, 3 Aug 2021 10:31:54 -0700
Subject: [PATCH 4/4] update website docs

---
 website/content/partials/components/builder-docker.mdx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/website/content/partials/components/builder-docker.mdx b/website/content/partials/components/builder-docker.mdx
index 06b8b8eb596..06802da5d9d 100644
--- a/website/content/partials/components/builder-docker.mdx
+++ b/website/content/partials/components/builder-docker.mdx
@@ -88,9 +88,9 @@ Set this when the Dockerfile is not APP-PATH/Dockerfile.
 
 #### platform
 
-Set platform if server is multi-platform capable.
+Set target platform to build container if server is multi-platform capable.
 
-Recommended usage with buildkit enabled.
+Must enable Docker buildkit to use the 'platform' flag.
 
 - Type: **string**
 - **Optional**