add an --auto flag for automated key creation and upload

README.md

@@ -22,6 +22,19 @@ To add accounts:
       IdentityFile /PATH/TO/PRIVATE/KEY
       IdentitiesOnly yes
 
+Or you can choose a fully-automated approach:
+
+    $ heroku accounts:add work --auto
+    Enter your Heroku credentials.
+    Email: work@example.org
+    Password: ******
+    Generating new SSH key
+    Generating public/private rsa key pair.
+    Your identification has been saved in ~/.ssh/identity.heroku.work.
+    Your public key has been saved in ~/.ssh/identity.heroku.work.pub.
+    Adding entry to ~/.ssh/config
+    Adding public key to Heroku account: work@example.org
+
 To switch an app to a different account:
 
     # in project root

lib/heroku/command/accounts.rb

@@ -25,13 +25,31 @@ def add
       :password      => password
     )
 
-    display ""
-    display "Add the following to your ~/.ssh/config"
-    display ""
-    display "Host heroku.#{name}"
-    display "  HostName heroku.com"
-    display "  IdentityFile /PATH/TO/PRIVATE/KEY"
-    display "  IdentitiesOnly yes"
+    if extract_option("--auto") then
+      display "Generating new SSH key"
+      system %{ ssh-keygen -t rsa -f #{account_ssh_key(name)} -N "" }
+
+      display "Adding entry to ~/.ssh/config"
+      File.open(File.expand_path("~/.ssh/config"), "a") do |file|
+        file.puts
+        file.puts "Host heroku.#{name}"
+        file.puts "  HostName heroku.com"
+        file.puts "  IdentityFile #{account_ssh_key(name)}"
+        file.puts "  IdentitiesOnly yes"
+      end
+
+      display "Adding public key to Heroku account: #{username}"
+      client = Heroku::Client.new(username, password)
+      client.add_key(File.read(File.expand_path(account_ssh_key(name) + ".pub")))
+    else
+      display ""
+      display "Add the following to your ~/.ssh/config"
+      display ""
+      display "Host heroku.#{name}"
+      display "  HostName heroku.com"
+      display "  IdentityFile /PATH/TO/PRIVATE/KEY"
+      display "  IdentitiesOnly yes"
+    end
   end
 
   def remove
@@ -92,6 +110,10 @@ def account_exists?(name)
     account_names.include?(name)
   end
 
+  def account_ssh_key(name)
+    "~/.ssh/identity.heroku.#{name}"
+  end
+
   def read_account(name)
     YAML::load_file(account_file(name))
   end