packer: Core.Build

packer/core.go

@@ -47,6 +47,35 @@ func NewCore(c *CoreConfig) (*Core, error) {
 	}, nil
 }
 
+// Build returns the Build object for the given name.
+func (c *Core) Build(n string) (Build, error) {
+	// Setup the builder
+	configBuilder, ok := c.template.Builders[n]
+	if !ok {
+		return nil, fmt.Errorf("no such build found: %s", n)
+	}
+	builder, err := c.components.Builder(configBuilder.Type)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"error initializing builder '%s': %s",
+			configBuilder.Type, err)
+	}
+	if builder == nil {
+		return nil, fmt.Errorf(
+			"builder type not found: %s", configBuilder.Type)
+	}
+
+	// TODO: template process name
+
+	return &coreBuild{
+		name:          n,
+		builder:       builder,
+		builderConfig: configBuilder.Config,
+		builderType:   configBuilder.Type,
+		variables:     c.variables,
+	}, nil
+}
+
 // Validate does a full validation of the template.
 //
 // This will automatically call template.Validate() in addition to doing

packer/testing.go

@@ -0,0 +1,44 @@
+package packer
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func TestCoreConfig(t *testing.T) *CoreConfig {
+	// Create a UI that is effectively /dev/null everywhere
+	var buf bytes.Buffer
+	ui := &BasicUi{
+		Reader:      &buf,
+		Writer:      ioutil.Discard,
+		ErrorWriter: ioutil.Discard,
+	}
+
+	// Create some test components
+	components := ComponentFinder{
+		Builder: func(n string) (Builder, error) {
+			if n != "test" {
+				return nil, nil
+			}
+
+			return &MockBuilder{}, nil
+		},
+	}
+
+	return &CoreConfig{
+		Cache:      &FileCache{CacheDir: os.TempDir()},
+		Components: components,
+		Ui:         ui,
+	}
+}
+
+func TestCore(t *testing.T, c *CoreConfig) *Core {
+	core, err := NewCore(c)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	return core
+}