github.phpd.cn/hashicorp/packer@v1.3.2/builder/googlecompute/step_create_ssh_key.go (about)

     1  package googlecompute
     2  
     3  import (
     4  	"context"
     5  	"crypto/rand"
     6  	"crypto/rsa"
     7  	"crypto/x509"
     8  	"encoding/pem"
     9  	"fmt"
    10  	"io/ioutil"
    11  	"os"
    12  
    13  	"github.com/hashicorp/packer/helper/multistep"
    14  	"github.com/hashicorp/packer/packer"
    15  	"golang.org/x/crypto/ssh"
    16  )
    17  
    18  // StepCreateSSHKey represents a Packer build step that generates SSH key pairs.
    19  type StepCreateSSHKey struct {
    20  	Debug        bool
    21  	DebugKeyPath string
    22  }
    23  
    24  // Run executes the Packer build step that generates SSH key pairs.
    25  // The key pairs are added to the ssh config
    26  func (s *StepCreateSSHKey) Run(_ context.Context, state multistep.StateBag) multistep.StepAction {
    27  	ui := state.Get("ui").(packer.Ui)
    28  	config := state.Get("config").(*Config)
    29  
    30  	if config.Comm.SSHPrivateKeyFile != "" {
    31  		ui.Say("Using existing SSH private key")
    32  		privateKeyBytes, err := ioutil.ReadFile(config.Comm.SSHPrivateKeyFile)
    33  		if err != nil {
    34  			state.Put("error", fmt.Errorf(
    35  				"Error loading configured private key file: %s", err))
    36  			return multistep.ActionHalt
    37  		}
    38  
    39  		config.Comm.SSHPrivateKey = privateKeyBytes
    40  		config.Comm.SSHPublicKey = nil
    41  
    42  		return multistep.ActionContinue
    43  	}
    44  
    45  	ui.Say("Creating temporary SSH key for instance...")
    46  	priv, err := rsa.GenerateKey(rand.Reader, 2048)
    47  	if err != nil {
    48  		err := fmt.Errorf("Error creating temporary ssh key: %s", err)
    49  		state.Put("error", err)
    50  		ui.Error(err.Error())
    51  		return multistep.ActionHalt
    52  	}
    53  
    54  	priv_blk := pem.Block{
    55  		Type:    "RSA PRIVATE KEY",
    56  		Headers: nil,
    57  		Bytes:   x509.MarshalPKCS1PrivateKey(priv),
    58  	}
    59  
    60  	pub, err := ssh.NewPublicKey(&priv.PublicKey)
    61  	if err != nil {
    62  		err := fmt.Errorf("Error creating temporary ssh key: %s", err)
    63  		state.Put("error", err)
    64  		ui.Error(err.Error())
    65  		return multistep.ActionHalt
    66  	}
    67  	config.Comm.SSHPrivateKey = pem.EncodeToMemory(&priv_blk)
    68  	config.Comm.SSHPublicKey = ssh.MarshalAuthorizedKey(pub)
    69  
    70  	if s.Debug {
    71  		ui.Message(fmt.Sprintf("Saving key for debug purposes: %s", s.DebugKeyPath))
    72  		f, err := os.Create(s.DebugKeyPath)
    73  		if err != nil {
    74  			state.Put("error", fmt.Errorf("Error saving debug key: %s", err))
    75  			return multistep.ActionHalt
    76  		}
    77  
    78  		// Write out the key
    79  		err = pem.Encode(f, &priv_blk)
    80  		f.Close()
    81  		if err != nil {
    82  			state.Put("error", fmt.Errorf("Error saving debug key: %s", err))
    83  			return multistep.ActionHalt
    84  		}
    85  	}
    86  	return multistep.ActionContinue
    87  }
    88  
    89  // Nothing to clean up. SSH keys are associated with a single GCE instance.
    90  func (s *StepCreateSSHKey) Cleanup(state multistep.StateBag) {}