Add ability to list snapshots

* First step for #249 
* Listing of all snapshots

README.md

@@ -259,6 +259,18 @@ Or just list images that you have created.
     My application image (id: 6376601, distro: Ubuntu)
     ....
 
+### List Current Snapshots
+
+    $ tugboat snapshots
+    code-freeze-backup-october (id: 2013184, resource_type: droplet, created_at: 2016-10-06T11:43:06Z)
+    test-admin 2017-05-31 (id: 20234485, resource_type: droplet, created_at: 2017-05-31T02:07:07Z)
+    test-admin 2017-11-08 (id: 21133567, resource_type: droplet, created_at: 2017-11-08T02:49:09Z)
+    test-admin 2017-11-15 (id: 22355454, resource_type: droplet, created_at: 2017-11-15T03:11:08Z)
+    test-admin 2017-11-22 (id: 24523423, resource_type: droplet, created_at: 2017-11-22T03:10:09Z)
+    test-admin 2017-11-29 (id: 26212345, resource_type: droplet, created_at: 2017-11-29T03:15:25Z)
+    ....
+
+
 ### List Available Sizes
 
     $ tugboat sizes

lib/tugboat/cli.rb

@@ -512,6 +512,20 @@ def resize(name = nil)
                                               'user_quiet' => options[:quiet])
     end
 
+    method_option 'per_page',
+                  type: :boolean,
+                  default: 20,
+                  aliases: '-p',
+                  desc: 'Chose how many results to fetch from the DigitalOcean API (larger is slower)'
+    desc 'snapshots [OPTIONS]', 'Retrieve a list of your snapshots'
+    def snapshots
+      Middleware.sequence_list_snapshots.call(
+                                             'tugboat_action' => __method__,
+                                             'user_quiet' => options[:quiet],
+                                             'per_page' => options['per_page'],
+                                             )
+    end
+
     desc 'password-reset FUZZY_NAME', 'Reset root password'
     method_option 'id',
                   type: :numeric,

lib/tugboat/middleware.rb

@@ -27,6 +27,7 @@ module Middleware
     autoload :ListImages, 'tugboat/middleware/list_images'
     autoload :ListRegions, 'tugboat/middleware/list_regions'
     autoload :ListSizes, 'tugboat/middleware/list_sizes'
+    autoload :ListSnapshots, 'tugboat/middleware/list_snapshots'
     autoload :ListSSHKeys, 'tugboat/middleware/list_ssh_keys'
     autoload :PasswordReset, 'tugboat/middleware/password_reset'
     autoload :ResizeDroplet, 'tugboat/middleware/resize_droplet'
@@ -231,6 +232,16 @@ def self.sequence_ssh_keys
       end
     end
 
+    # Display a list of available SSH keys
+    def self.sequence_list_snapshots
+      ::Middleware::Builder.new do
+        use InjectConfiguration
+        use CheckConfiguration
+        use InjectClient
+        use ListSnapshots
+      end
+    end
+
     # Create a droplet
     def self.sequence_add_key
       ::Middleware::Builder.new do

lib/tugboat/middleware/list_snapshots.rb

@@ -0,0 +1,34 @@
+module Tugboat
+  module Middleware
+    # Check if the client has set-up configuration yet.
+    class ListSnapshots < Base
+      def call(env)
+        ocean = env['droplet_kit']
+
+        verify_credentials(ocean)
+
+        response = ocean.snapshots.all(per_page: env['per_page'])
+
+        has_one = false
+
+        response.each do |snapshot|
+          has_one = true
+
+          say "#{snapshot.name} (id: #{snapshot.id}, resource_type: #{snapshot.resource_type}, created_at: #{snapshot.created_at})"
+        end
+
+        unless has_one
+          say "You don't appear to have any snapshots.", :red
+        end
+
+        @app.call(env)
+      end
+
+      private
+
+      def droplet_id_to_url(id)
+        ", url: 'https://cloud.digitalocean.com/droplets/#{id}'"
+      end
+    end
+  end
+end