github.com/rothwerx/packer@v0.9.0/builder/googlecompute/step_check_existing_image.go (about) 1 package googlecompute 2 3 import ( 4 "fmt" 5 6 "github.com/mitchellh/multistep" 7 "github.com/mitchellh/packer/packer" 8 ) 9 10 // StepCheckExistingImage represents a Packer build step that checks if the 11 // target image already exists, and aborts immediately if so. 12 type StepCheckExistingImage int 13 14 // Run executes the Packer build step that checks if the image already exists. 15 func (s *StepCheckExistingImage) Run(state multistep.StateBag) multistep.StepAction { 16 config := state.Get("config").(*Config) 17 driver := state.Get("driver").(Driver) 18 ui := state.Get("ui").(packer.Ui) 19 20 ui.Say("Checking image does not exist...") 21 exists := driver.ImageExists(config.ImageName) 22 if exists { 23 err := fmt.Errorf("Image %s already exists", config.ImageName) 24 state.Put("error", err) 25 ui.Error(err.Error()) 26 return multistep.ActionHalt 27 } 28 29 return multistep.ActionContinue 30 } 31 32 // Cleanup. 33 func (s *StepCheckExistingImage) Cleanup(state multistep.StateBag) {}