From 17c6578583e61b144eb6071a900b589a3a9d26eb Mon Sep 17 00:00:00 2001
From: Bilal Amarni <bilal.amarni@gmail.com>
Date: Thu, 3 Mar 2016 10:35:32 +0100
Subject: [PATCH] [DigitalOcean] Allow to use an existing SSH key (closes
 #1445)

Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com>
---
 docs/drivers/digital-ocean.md        |  2 ++
 drivers/digitalocean/digitalocean.go | 27 ++++++++++++++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/docs/drivers/digital-ocean.md b/docs/drivers/digital-ocean.md
index c18bb08468..491c4e95d4 100644
--- a/docs/drivers/digital-ocean.md
+++ b/docs/drivers/digital-ocean.md
@@ -29,6 +29,7 @@ Options:
 -   `--digitalocean-userdata`: Path to file containing User Data for the droplet.
 -   `--digitalocean-ssh-user`: SSH username.
 -   `--digitalocean-ssh-port`: SSH port.
+-   `--digitalocean-ssh-key-fingerprint`: Use an existing SSH key instead of creating a new one, see [SSH keys](https://developers.digitalocean.com/documentation/v2/#ssh-keys).
 
 The DigitalOcean driver will use `ubuntu-15-10-x64` as the default image.
 
@@ -46,3 +47,4 @@ Environment variables and default values:
 | `--digitalocean-userdata`           | `DIGITALOCEAN_USERDATA`           | -                  |
 | `--digitalocean-ssh-user`           | `DIGITALOCEAN_SSH_USER`           | `root`             |
 | `--digitalocean-ssh-port`           | `DIGITALOCEAN_SSH_PORT`           | 22                 |
+| `--digitalocean-ssh-key-fingerprint`| `DIGITALOCEAN_SSH_KEY_FINGERPRINT`| -                  |
diff --git a/drivers/digitalocean/digitalocean.go b/drivers/digitalocean/digitalocean.go
index 4b6a7293ec..58aa8603c5 100644
--- a/drivers/digitalocean/digitalocean.go
+++ b/drivers/digitalocean/digitalocean.go
@@ -24,6 +24,7 @@ type Driver struct {
 	Image             string
 	Region            string
 	SSHKeyID          int
+	SSHKeyFingerprint string
 	Size              string
 	IPv6              bool
 	Backups           bool
@@ -54,6 +55,11 @@ func (d *Driver) GetCreateFlags() []mcnflag.Flag {
 			Usage:  "SSH username",
 			Value:  defaultSSHUser,
 		},
+		mcnflag.StringFlag{
+			EnvVar: "DIGITALOCEAN_SSH_KEY_FINGERPRINT",
+			Name:   "digitalocean-ssh-key-fingerprint",
+			Usage:  "SSH key fingerprint",
+		},
 		mcnflag.IntFlag{
 			EnvVar: "DIGITALOCEAN_SSH_PORT",
 			Name:   "digitalocean-ssh-port",
@@ -133,6 +139,7 @@ func (d *Driver) SetConfigFromFlags(flags drivers.DriverOptions) error {
 	d.UserDataFile = flags.String("digitalocean-userdata")
 	d.SSHUser = flags.String("digitalocean-ssh-user")
 	d.SSHPort = flags.Int("digitalocean-ssh-port")
+	d.SSHKeyFingerprint = flags.String("digitalocean-ssh-key-fingerprint")
 	d.SetSwarmConfigFromFlags(flags)
 
 	if d.AccessToken == "" {
@@ -232,6 +239,14 @@ func (d *Driver) Create() error {
 }
 
 func (d *Driver) createSSHKey() (*godo.Key, error) {
+	if d.SSHKeyFingerprint != "" {
+		key, resp, err := d.getClient().Keys.GetByFingerprint(d.SSHKeyFingerprint)
+		if err != nil && resp.StatusCode == 404 {
+			return nil, fmt.Errorf("Digital Ocean SSH key with fingerprint %s doesn't exist", d.SSHKeyFingerprint)
+		}
+		return key, err
+	}
+
 	if err := ssh.GenerateSSHKey(d.GetSSHKeyPath()); err != nil {
 		return nil, err
 	}
@@ -305,11 +320,13 @@ func (d *Driver) Kill() error {
 
 func (d *Driver) Remove() error {
 	client := d.getClient()
-	if resp, err := client.Keys.DeleteByID(d.SSHKeyID); err != nil {
-		if resp.StatusCode == 404 {
-			log.Infof("Digital Ocean SSH key doesn't exist, assuming it is already deleted")
-		} else {
-			return err
+	if d.SSHKeyFingerprint == "" {
+		if resp, err := client.Keys.DeleteByID(d.SSHKeyID); err != nil {
+			if resp.StatusCode == 404 {
+				log.Infof("Digital Ocean SSH key doesn't exist, assuming it is already deleted")
+			} else {
+				return err
+			}
 		}
 	}
 	if resp, err := client.Droplets.Delete(d.DropletID); err != nil {