Merge lp:~frankban/lpsetup/urandom-hack into lp:lpsetup

[Francesco Banconi]

Added the random/urandom hack (ported from setuplxc).

[Gary Poster (gary)]

Thank you, Francesco. Please add an additional sentence to the help description that gives a serious warning about it. Draft of the kinds of things I'm thinking of: "This reduces the actual randomness of your system's random number generator and thereby reduces security. Use only if determined to be necessary for this machine, and only if the machine is only used for tasks identified as low-risk, such as running tests." Otherwise good.

review: Approve

[lp:~frankban/lpsetup/urandom-hack]

12. By Francesco Banconi on 2012-04-10

Added a warning about --use-urandom option.

=== modified file 'lpsetup/subcommands/install.py'
--- lpsetup/subcommands/install.py	2012-03-30 10:52:41 +0000
+++ lpsetup/subcommands/install.py	2012-04-10 09:27:39 +0000
@@ -114,7 +114,7 @@
 
 def initialize(
     user, full_name, email, lpuser, private_key, public_key, valid_ssh_keys,
-    ssh_key_path, dependencies_dir, directory):
+    ssh_key_path, use_urandom, dependencies_dir, directory):
     """Initialize host machine."""
     # Install necessary deb packages.  This requires Oneiric or later.
     call('apt-get', 'update')
@@ -165,6 +165,12 @@
         for line in lines:
             location = line.format(checkout_dir=checkout_dir, lpuser=lpuser)
             file_append(bzr_locations, location)
+    # rng-tools is used to set /dev/urandom as random data source, avoiding
+    # entropy exhaustion during automated parallel tests.
+    if use_urandom:
+        apt_get_install('rng-tools', caller=call)
+        file_append('/etc/default/rng-tools', 'HRNGDEVICE=/dev/urandom')
+        call('/etc/init.d/rng-tools', 'start')
 
 
 def setup_apt(no_repositories=True):
@@ -218,7 +224,7 @@
         (initialize,
          'user', 'full_name', 'email', 'lpuser',
          'private_key', 'public_key', 'valid_ssh_keys', 'ssh_key_path',
-         'dependencies_dir', 'directory'),
+         'use_urandom', 'dependencies_dir', 'directory'),
         (setup_apt,
          'no_repositories'),
         (setup_launchpad,
@@ -289,3 +295,7 @@
         parser.add_argument(
             '-N', '--no-repositories', action='store_true',
             help='Do not add APT repositories.')
+        parser.add_argument(
+            '-U', '--use-urandom', action='store_true',
+            help='Use /dev/urandom to feed /dev/random and avoid '
+                 'entropy exhaustion.')

=== modified file 'lpsetup/subcommands/lxcinstall.py'
--- lpsetup/subcommands/lxcinstall.py	2012-03-30 16:52:14 +0000
+++ lpsetup/subcommands/lxcinstall.py	2012-04-10 09:27:39 +0000
@@ -158,7 +158,7 @@
         (install.initialize,
          'user', 'full_name', 'email', 'lpuser',
          'private_key', 'public_key', 'valid_ssh_keys', 'ssh_key_path',
-         'dependencies_dir', 'directory'),
+         'use_urandom', 'dependencies_dir', 'directory'),
         (create_lxc,
          'user', 'lxc_name', 'lxc_arch', 'lxc_os'),
         (start_lxc,