github.com/ttysteale/packer@v0.8.2-0.20150708160520-e5f8ea386ed8/builder/amazon/common/ssh.go (about)

     1  package common
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"time"
     7  
     8  	"github.com/aws/aws-sdk-go/service/ec2"
     9  	"github.com/mitchellh/multistep"
    10  	"golang.org/x/crypto/ssh"
    11  )
    12  
    13  // SSHHost returns a function that can be given to the SSH communicator
    14  // for determining the SSH address based on the instance DNS name.
    15  func SSHHost(e *ec2.EC2, private bool) func(multistep.StateBag) (string, error) {
    16  	return func(state multistep.StateBag) (string, error) {
    17  		for j := 0; j < 2; j++ {
    18  			var host string
    19  			i := state.Get("instance").(*ec2.Instance)
    20  			if i.VPCID != nil && *i.VPCID != "" {
    21  				if i.PublicIPAddress != nil && *i.PublicIPAddress != "" && !private {
    22  					host = *i.PublicIPAddress
    23  				} else {
    24  					host = *i.PrivateIPAddress
    25  				}
    26  			} else if i.PublicDNSName != nil && *i.PublicDNSName != "" {
    27  				host = *i.PublicDNSName
    28  			}
    29  
    30  			if host != "" {
    31  				return host, nil
    32  			}
    33  
    34  			r, err := e.DescribeInstances(&ec2.DescribeInstancesInput{
    35  				InstanceIDs: []*string{i.InstanceID},
    36  			})
    37  			if err != nil {
    38  				return "", err
    39  			}
    40  
    41  			if len(r.Reservations) == 0 || len(r.Reservations[0].Instances) == 0 {
    42  				return "", fmt.Errorf("instance not found: %s", *i.InstanceID)
    43  			}
    44  
    45  			state.Put("instance", &r.Reservations[0].Instances[0])
    46  			time.Sleep(1 * time.Second)
    47  		}
    48  
    49  		return "", errors.New("couldn't determine IP address for instance")
    50  	}
    51  }
    52  
    53  // SSHConfig returns a function that can be used for the SSH communicator
    54  // config for connecting to the instance created over SSH using the generated
    55  // private key.
    56  func SSHConfig(username string) func(multistep.StateBag) (*ssh.ClientConfig, error) {
    57  	return func(state multistep.StateBag) (*ssh.ClientConfig, error) {
    58  		privateKey := state.Get("privateKey").(string)
    59  
    60  		signer, err := ssh.ParsePrivateKey([]byte(privateKey))
    61  		if err != nil {
    62  			return nil, fmt.Errorf("Error setting up SSH config: %s", err)
    63  		}
    64  
    65  		return &ssh.ClientConfig{
    66  			User: username,
    67  			Auth: []ssh.AuthMethod{
    68  				ssh.PublicKeys(signer),
    69  			},
    70  		}, nil
    71  	}
    72  }