add buildx and platform to release_metadata.json (#23)

cmd/app/main.go

@@ -35,7 +35,7 @@ func main() {
 		log.Fatalln("error loading MANIFEST_PARAMS:", err)
 	}
 
-	image, err := app.Run(
+	result, err := app.Run(
 		ecr.New(session.Must(session.NewSession())),
 		&app.ExecCommandRunner{OutputStream: os.Stdout, ErrorStream: os.Stderr},
 		params,
@@ -47,11 +47,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	data, err := json.Marshal(map[string]string{"image": image})
-	if err != nil {
-		log.Fatal(err)
-	}
-	if err := ioutil.WriteFile("/release-metadata.json", data, 0644); err != nil {
+	if err := ioutil.WriteFile("/release-metadata.json", []byte(result), 0644); err != nil {
 		log.Fatalln("error writing release metadata:", err)
 	}
 }

internal/app/app.go

@@ -3,10 +3,12 @@ package app
 import (
 	"bufio"
 	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"log"
 	"os"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/aws/aws-sdk-go/service/ecr"
@@ -57,7 +59,15 @@ func Run(ecrClient ecriface.ECRAPI, runner CommandRunner, params map[string]inte
 		build(config, image, runner)
 	}
 
-	return image, nil
+	data, err := json.Marshal(map[string]string{
+		"image":    image,
+		"buildx":   strconv.FormatBool(config.buildx),
+		"platform": config.platform})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return string(data), nil
 }
 
 func build(config *config, image string, runner CommandRunner) {