package file /* The File builder creates an artifact from a file. Because it does not require any virutalization or network resources, it's very fast and useful for testing. */ import ( "fmt" "io" "io/ioutil" "os" "github.com/mitchellh/multistep" "github.com/mitchellh/packer/packer" ) const BuilderId = "packer.file" type Builder struct { config *Config runner multistep.Runner } func (b *Builder) Prepare(raws ...interface{}) ([]string, error) { c, warnings, errs := NewConfig(raws...) if errs != nil { return warnings, errs } b.config = c return warnings, nil } // Run is where the actual build should take place. It takes a Build and a Ui. func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) { artifact := new(FileArtifact) if b.config.Source != "" { source, err := os.Open(b.config.Source) defer source.Close() if err != nil { return nil, err } // Create will truncate an existing file target, err := os.Create(b.config.Target) defer target.Close() if err != nil { return nil, err } ui.Say(fmt.Sprintf("Copying %s to %s", source.Name(), target.Name())) bytes, err := io.Copy(target, source) if err != nil { return nil, err } ui.Say(fmt.Sprintf("Copied %d bytes", bytes)) artifact.filename = target.Name() } else { // We're going to write Contents; if it's empty we'll just create an // empty file. err := ioutil.WriteFile(b.config.Target, []byte(b.config.Content), 0600) if err != nil { return nil, err } artifact.filename = b.config.Target } return artifact, nil } // Cancel cancels a possibly running Builder. This should block until // the builder actually cancels and cleans up after itself. func (b *Builder) Cancel() { b.runner.Cancel() }