add ntp config module

Add support for installing and configuring ntp service, exposing the
minimum config of servers or pools to be added. If none are defined
then fallback on generating a list of pools by distro hosted at
pool.ntp.org (which matches what's found in the default ntp.conf
shipped in the respective distro).

1 files changed, 106 insertions, 0 deletions

diff --git a/cloudinit/config/cc_ntp.py b/cloudinit/config/cc_ntp.py
new file mode 100644
index 00000000..ad69aa34
--- /dev/null
+++ b/cloudinit/config/cc_ntp.py
@@ -0,0 +1,106 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2016 Canonical Ltd.
+#
+#    Author: Ryan Harper <ryan.harper@canonical.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from cloudinit import log as logging
+from cloudinit.settings import PER_INSTANCE
+from cloudinit import templater
+from cloudinit import type_utils
+from cloudinit import util
+
+import os
+
+LOG = logging.getLogger(__name__)
+
+frequency = PER_INSTANCE
+NTP_CONF = '/etc/ntp.conf'
+NR_POOL_SERVERS = 4
+distros = ['centos', 'debian', 'fedora', 'opensuse', 'ubuntu']
+
+
+def handle(name, cfg, cloud, log, _args):
+    """
+    Enable and configure ntp
+
+    ntp:
+       pools: ['0.{{distro}}.pool.ntp.org', '1.{{distro}}.pool.ntp.org']
+       servers: ['192.168.2.1']
+
+    """
+
+    ntp_cfg = cfg.get('ntp', {})
+
+    if not isinstance(ntp_cfg, (dict)):
+        raise RuntimeError(("'ntp' key existed in config,"
+                            " but not a dictionary type,"
+                            " is a %s %instead"), type_utils.obj_name(ntp_cfg))
+
+    if 'ntp' not in cfg:
+        LOG.debug("Skipping module named %s,"
+                  "not present or disabled by cfg", name)
+        return True
+
+    install_ntp(cloud.distro.install_packages, packages=['ntp'],
+                check_exe="ntpd")
+    rename_ntp_conf()
+    write_ntp_config_template(ntp_cfg, cloud)
+
+
+def install_ntp(install_func, packages=None, check_exe="ntpd"):
+    if util.which(check_exe):
+        return
+    if packages is None:
+        packages = ['ntp']
+
+    install_func(packages)
+
+
+def rename_ntp_conf(config=NTP_CONF):
+    if os.path.exists(config):
+        util.rename(config, config + ".dist")
+
+
+def generate_server_names(distro):
+    names = []
+    for x in range(0, NR_POOL_SERVERS):
+        name = "%d.%s.pool.ntp.org" % (x, distro)
+        names.append(name)
+    return names
+
+
+def write_ntp_config_template(cfg, cloud):
+    servers = cfg.get('servers', [])
+    pools = cfg.get('pools', [])
+
+    if len(servers) == 0 and len(pools) == 0:
+        LOG.debug('Adding distro default ntp pool servers')
+        pools = generate_server_names(cloud.distro.name)
+
+    params = {
+        'servers': servers,
+        'pools': pools,
+    }
+
+    template_fn = cloud.get_template_filename('ntp.conf.%s' %
+                                              (cloud.distro.name))
+    if not template_fn:
+        template_fn = cloud.get_template_filename('ntp.conf')
+        if not template_fn:
+            raise RuntimeError(("No template found, "
+                                "not rendering %s"), NTP_CONF)
+
+    templater.render_to_file(template_fn, NTP_CONF, params)