Merge pull request #322 from mnottale/lib-render

lib: Add an accessible Render function.

Author: chris-crone

lib/lib.go

@@ -0,0 +1,21 @@
+package lib
+
+import (
+	"github.com/docker/app/internal/packager"
+	"github.com/docker/app/internal/render"
+	yaml "gopkg.in/yaml.v2"
+)
+
+// Render renders the application into a Compose file.
+func Render(appname string, settingsFiles []string, settings map[string]string) ([]byte, error) {
+	app, err := packager.Extract(appname)
+	if err != nil {
+		return nil, err
+	}
+	defer app.Cleanup()
+	rendered, err := render.Render(app.AppName, nil, settingsFiles, settings)
+	if err != nil {
+		return nil, err
+	}
+	return yaml.Marshal(rendered)
+}