package chroot import ( "fmt" "github.com/mitchellh/goamz/aws" "github.com/mitchellh/goamz/ec2" "github.com/mitchellh/multistep" "github.com/mitchellh/packer/packer" "log" ) // StepInstanceInfo verifies that this builder is running on an EC2 instance. type StepInstanceInfo struct{} func (s *StepInstanceInfo) Run(state multistep.StateBag) multistep.StepAction { ec2conn := state.Get("ec2").(*ec2.EC2) ui := state.Get("ui").(packer.Ui) // Get our own instance ID ui.Say("Gathering information about this EC2 instance...") instanceIdBytes, err := aws.GetMetaData("instance-id") if err != nil { log.Printf("Error: %s", err) err := fmt.Errorf( "Error retrieving the ID of the instance Packer is running on.\n" + "Please verify Packer is running on a proper AWS EC2 instance.") state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } instanceId := string(instanceIdBytes) log.Printf("Instance ID: %s", instanceId) // Query the entire instance metadata instancesResp, err := ec2conn.Instances([]string{instanceId}, ec2.NewFilter()) if err != nil { err := fmt.Errorf("Error getting instance data: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } if len(instancesResp.Reservations) == 0 { err := fmt.Errorf("Error getting instance data: no instance found.") state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } instance := &instancesResp.Reservations[0].Instances[0] state.Put("instance", instance) return multistep.ActionContinue } func (s *StepInstanceInfo) Cleanup(multistep.StateBag) {}