diff --git a/server/module_lib/icon_lib.py b/server/module_lib/icon_lib.py
index c015dd9..f60691b 100644
--- a/server/module_lib/icon_lib.py
+++ b/server/module_lib/icon_lib.py
@@ -46,7 +46,9 @@ class IconModule(object):
     self.ExecChroot('ldconfig')
 
   def InstallPackages(self, *packages):
-    self.ExecChroot('apt-get', 'install', '--assume-yes', '--no-install-recommends', *packages)
+    env = os.environ.copy()
+    env['DEBIAN_FRONTEND'] = 'noninteractive'
+    self.ExecChroot('apt-get', 'install', '--assume-yes', '--no-install-recommends', *packages, env=env)
 
   def InstallPythonPackages(self, *packages):
     self.InstallPackages('python-pip')
diff --git a/server/modules/adduser.py b/server/modules/adduser.py
index 23f0bfd..576a5fd 100755
--- a/server/modules/adduser.py
+++ b/server/modules/adduser.py
@@ -3,7 +3,8 @@
 import argparse
 import os
 import shutil
-import subprocess
+
+import icon_lib
 
 
 parser = argparse.ArgumentParser(description='iconograph adduser')
@@ -28,18 +29,10 @@ parser.add_argument(
 FLAGS = parser.parse_args()
 
 
-def Exec(*args, **kwargs):
-    print('+', args)
-    subprocess.check_call(args, **kwargs)
-
-
-def ExecChroot(*args, **kwargs):
-    Exec('chroot', FLAGS.chroot_path, *args, **kwargs)
-
-
 def main():
-  ExecChroot('adduser', '--system', '--group', '--disabled-password', 
-             '--shell=/bin/bash', FLAGS.username)
+  module = icon_lib.IconModule(FLAGS.chroot_path)
+  module.ExecChroot('adduser', '--system', '--group', '--disabled-password', 
+                    '--shell=/bin/bash', FLAGS.username)
 
   if FLAGS.sudo:
     with open(os.path.join(FLAGS.chroot_path, 'etc', 'sudoers.d', FLAGS.username), 'w') as fh:
@@ -50,7 +43,7 @@ def main():
     dest_path = os.path.join(dest_dir, 'authorized_keys')
     os.mkdir(dest_dir)
     shutil.copy(FLAGS.authorized_keys_file, dest_path)
-    ExecChroot('chown', '--recursive', '%s:%s' % (FLAGS.username, FLAGS.username), '/home/%s' % FLAGS.username)
+    module.ExecChroot('chown', '--recursive', '%s:%s' % (FLAGS.username, FLAGS.username), '/home/%s' % FLAGS.username)
 
 
 if __name__ == '__main__':
diff --git a/server/modules/autoimage.py b/server/modules/autoimage.py
index 2b7ad81..441f1af 100755
--- a/server/modules/autoimage.py
+++ b/server/modules/autoimage.py
@@ -5,6 +5,8 @@ import os
 import shutil
 import subprocess
 
+import icon_lib
+
 
 parser = argparse.ArgumentParser(description='iconograph autoimage')
 parser.add_argument(
@@ -56,26 +58,14 @@ parser.add_argument(
 FLAGS = parser.parse_args()
 
 
-def Exec(*args, **kwargs):
-  print('+', args)
-  subprocess.check_call(args, **kwargs)
-
-
-def ExecChroot(*args, **kwargs):
-  Exec('chroot', FLAGS.chroot_path, *args, **kwargs)
-
-
 def main():
-  ExecChroot(
-      'apt-get',
-      'install',
-      '--assume-yes',
-      'git', 'grub-pc', 'python3-openssl', 'python3-requests')
+  module = icon_lib.IconModule(FLAGS.chroot_path)
+  module.InstallPackages('git', 'grub-pc', 'python3-openssl', 'python3-requests')
 
   os.makedirs(os.path.join(FLAGS.chroot_path, 'icon', 'config'), exist_ok=True)
 
   if not os.path.exists(os.path.join(FLAGS.chroot_path, 'icon', 'iconograph')):
-    ExecChroot(
+    module.ExecChroot(
         'git',
         'clone',
         'https://github.com/robot-tools/iconograph.git',
diff --git a/server/modules/certclient.py b/server/modules/certclient.py
index 847414c..85b2c4c 100755
--- a/server/modules/certclient.py
+++ b/server/modules/certclient.py
@@ -5,6 +5,8 @@ import os
 import shutil
 import subprocess
 
+import icon_lib
+
 
 parser = argparse.ArgumentParser(description='iconograph autoimage')
 parser.add_argument(
@@ -45,33 +47,21 @@ parser.add_argument(
 FLAGS = parser.parse_args()
 
 
-def Exec(*args, **kwargs):
-  print('+', args)
-  subprocess.check_call(args, **kwargs)
-
-
-def ExecChroot(*args, **kwargs):
-  Exec('chroot', FLAGS.chroot_path, *args, **kwargs)
-
-
 def main():
-  ExecChroot(
-      'apt-get',
-      'install',
-      '--assume-yes',
-      'git', 'python3-requests', 'openssl')
+  module = icon_lib.IconModule(FLAGS.chroot_path)
+  module.InstallPackages('git', 'python3-requests', 'openssl')
 
   os.makedirs(os.path.join(FLAGS.chroot_path, 'icon', 'config'), exist_ok=True)
 
   if not os.path.exists(os.path.join(FLAGS.chroot_path, 'icon', 'iconograph')):
-    ExecChroot(
+    module.ExecChroot(
         'git',
         'clone',
         'https://github.com/robot-tools/iconograph.git',
         'icon/iconograph')
 
   if not os.path.exists(os.path.join(FLAGS.chroot_path, 'icon', 'certserver')):
-    ExecChroot(
+    module.ExecChroot(
         'git',
         'clone',
         'https://github.com/robot-tools/certserver.git',
diff --git a/server/modules/iconograph.py b/server/modules/iconograph.py
index 7527ee8..e60045a 100755
--- a/server/modules/iconograph.py
+++ b/server/modules/iconograph.py
@@ -5,6 +5,8 @@ import os
 import shutil
 import subprocess
 
+import icon_lib
+
 
 parser = argparse.ArgumentParser(description='iconograph install module')
 parser.add_argument(
@@ -29,27 +31,16 @@ parser.add_argument(
 FLAGS = parser.parse_args()
 
 
-def Exec(*args, **kwargs):
-  print('+', args)
-  subprocess.check_call(args, **kwargs)
-
-
-def ExecChroot(*args, **kwargs):
-  Exec('chroot', FLAGS.chroot_path, *args, **kwargs)
-
-
 def main():
-  ExecChroot(
-      'apt-get',
-      'install',
-      '--assume-yes',
+  module = icon_lib.IconModule(FLAGS.chroot_path)
+  module.InstallPackages(
       'daemontools-run', 'genisoimage', 'git', 'python3-openssl',
       'python3-requests', 'python3-ws4py')
 
   os.makedirs(os.path.join(FLAGS.chroot_path, 'icon', 'config'), exist_ok=True)
 
   if not os.path.exists(os.path.join(FLAGS.chroot_path, 'icon', 'iconograph')):
-    ExecChroot(
+    module.ExecChroot(
         'git',
         'clone',
         'https://github.com/robot-tools/iconograph.git',
diff --git a/server/modules/openssh.py b/server/modules/openssh.py
index 2643cd9..7917659 100755
--- a/server/modules/openssh.py
+++ b/server/modules/openssh.py
@@ -3,7 +3,8 @@
 import argparse
 import glob
 import os
-import subprocess
+
+import icon_lib
 
 
 parser = argparse.ArgumentParser(description='iconograph openssh')
@@ -15,21 +16,9 @@ parser.add_argument(
 FLAGS = parser.parse_args()
 
 
-def Exec(*args, **kwargs):
-  print('+', args)
-  subprocess.check_call(args, **kwargs)
-
-
-def ExecChroot(*args, **kwargs):
-  Exec('chroot', FLAGS.chroot_path, *args, **kwargs)
-
-
 def main():
-  ExecChroot(
-      'apt-get',
-      'install',
-      '--assume-yes',
-      'openssh-server')
+  module = icon_lib.IconModule(FLAGS.chroot_path)
+  module.InstallPackages('openssh-server')
 
   for path in glob.glob(os.path.join(FLAGS.chroot_path, 'etc', 'ssh', 'ssh_host_*')):
     os.unlink(path)