Merge pull request #129 from sorenisanerd/docker-platforms

Allow specifying Docker build platforms

README.md

@@ -408,9 +408,12 @@ sheet][ref-pattern-cheat-sheet]. This option is not defined by default.
 
 If `enabled` is set to true, the generated `Dockerfile` is build and pushed to repository path under `ghcr.io`.
 
+To build for more or other platforms than the default (linux/amd64), you can set the `platforms` field to a list of platforms to build for. The format is the same as for the `--platform` flag of `docker buildx build`.
+
 ```yaml
 pushContainerToGhcr:
   enabled: true
+  platforms: linux/amd64,linux/arm64
 ```
 
 ### `githubWorkflow.release`

internal/core/config.go

@@ -152,7 +152,8 @@ type LicenseWorkflowConfig struct {
 }
 
 type PushContainerToGhcrConfig struct {
-	Enabled bool `yaml:"enabled"`
+	Enabled   bool   `yaml:"enabled"`
+	Platforms string `yaml:"platforms"`
 }
 
 type ReleaseWorkflowConfig struct {

internal/core/constants.go

@@ -35,6 +35,8 @@ const (
 
 	DockerLoginAction     = "docker/login-action@v3"
 	DockerMetadataAction  = "docker/metadata-action@v5"
+	DockerBuildxAction    = "docker/setup-buildx-action@v3"
+	DockerQemuAction      = "docker/setup-qemu-action@v3"
 	DockerBuildPushAction = "docker/build-push-action@v5"
 
 	CodeqlInitAction      = "github/codeql-action/init@v2"

internal/ghworkflow/workflow_ghcr.go

@@ -56,15 +56,30 @@ type=semver,pattern=v{{major}}.{{minor}}
 type=semver,pattern=v{{major}}`,
 		},
 	})
+
+	buildPushWith := map[string]any{
+		"context": ".",
+		"push":    true,
+		"tags":    "${{ steps.meta.outputs.tags }}",
+		"labels":  "${{ steps.meta.outputs.labels }}",
+	}
+
+	if cfg.PushContainerToGhcr.Platforms != "" {
+		j.addStep(jobStep{
+			Name: "Set up QEMU",
+			Uses: core.DockerQemuAction,
+		})
+		j.addStep(jobStep{
+			Name: "Set up Docker Buildx",
+			Uses: core.DockerBuildxAction,
+		})
+		buildPushWith["platforms"] = cfg.PushContainerToGhcr.Platforms
+	}
+
 	j.addStep(jobStep{
 		Name: "Build and push Docker image",
 		Uses: core.DockerBuildPushAction,
-		With: map[string]any{
-			"context": ".",
-			"push":    true,
-			"tags":    "${{ steps.meta.outputs.tags }}",
-			"labels":  "${{ steps.meta.outputs.labels }}",
-		},
+		With: buildPushWith,
 	})
 	w.Jobs = map[string]job{"build-and-push-image": j}