builder/digitalocean: Add acceptance test for creating Droplet using image ID.

builder/digitalocean/builder_acc_test.go

@@ -1,17 +1,29 @@
 package digitalocean
 
 import (
+	"context"
+	"fmt"
 	"os"
 	"testing"
 
+	"github.com/digitalocean/godo"
 	builderT "github.com/hashicorp/packer/helper/builder/testing"
+	"golang.org/x/oauth2"
 )
 
 func TestBuilderAcc_basic(t *testing.T) {
 	builderT.Test(t, builderT.TestCase{
 		PreCheck: func() { testAccPreCheck(t) },
 		Builder:  &Builder{},
-		Template: testBuilderAccBasic,
+		Template: fmt.Sprintf(testBuilderAccBasic, "ubuntu-20-04-x64"),
+	})
+}
+
+func TestBuilderAcc_imageId(t *testing.T) {
+	builderT.Test(t, builderT.TestCase{
+		PreCheck: func() { testAccPreCheck(t) },
+		Builder:  &Builder{},
+		Template: makeTemplateWithImageId(t),
 	})
 }
 
@@ -21,13 +33,26 @@ func testAccPreCheck(t *testing.T) {
 	}
 }
 
+func makeTemplateWithImageId(t *testing.T) string {
+	token := os.Getenv("DIGITALOCEAN_API_TOKEN")
+	client := godo.NewClient(oauth2.NewClient(context.TODO(), &apiTokenSource{
+		AccessToken: token,
+	}))
+	image, _, err := client.Images.GetBySlug(context.TODO(), "ubuntu-20-04-x64")
+	if err != nil {
+		t.Fatalf("failed to retrieve image ID: %s", err)
+	}
+
+	return fmt.Sprintf(testBuilderAccBasic, image.ID)
+}
+
 const testBuilderAccBasic = `
 {
 	"builders": [{
 		"type": "test",
 		"region": "nyc2",
 		"size": "s-1vcpu-1gb",
-		"image": "ubuntu-20-04-x64",
+		"image": "%v",
 		"ssh_username": "root",
 		"user_data": "",
 		"user_data_file": ""