Configure NTP.

We use a "master" NTP server, which synchronizes against stratum 1
servers (hence is a stratum 2 itself); all other clients synchronize to
this master server through IPSec.

6 files changed, 86 insertions, 1 deletions

diff --git a/group_vars/all.yml b/group_vars/all.yml
index b9e025f..26448c4 100644
--- a/group_vars/all.yml
+++ b/group_vars/all.yml
@@ -12,3 +12,4 @@ MTA_out: { IPv4: outgoing.fripost.org, port: 2525 }
 LDA:     { IPv4: lda.fripost.org,      port: 2526 }
 
 LDAP_provider: host1.libvirt.guilhem.org
+NTP_master: host1.libvirt.guilhem.org
diff --git a/roles/common/handlers/main.yml b/roles/common/handlers/main.yml
index 54643ed..2f4f900 100644
--- a/roles/common/handlers/main.yml
+++ b/roles/common/handlers/main.yml
@@ -29,6 +29,9 @@
   # pattern=init as a dummy assumption.
   service: name=networking pattern=init state=reloaded
 
+- name: Restart ntp
+  service: name=ntp state=restarted
+
 # TODO: should be in a separate file, since it's used by other roles
 - name: Restart Postfix
   service: name=postfix state=restarted
diff --git a/roles/common/tasks/main.yml b/roles/common/tasks/main.yml
index 355b2df..76967e6 100644
--- a/roles/common/tasks/main.yml
+++ b/roles/common/tasks/main.yml
@@ -8,4 +8,5 @@
 - include: fail2ban.yml tags=fail2ban
 - include: ipsec.yml    tags=strongswan,ipsec
 - include: logging.yml  tags=logging
+- include: ntp.yml      tags=ntp
 - include: mail.yml     tags=mail,postfix
diff --git a/roles/common/tasks/ntp.yml b/roles/common/tasks/ntp.yml
new file mode 100644
index 0000000..94d7696
--- /dev/null
+++ b/roles/common/tasks/ntp.yml
@@ -0,0 +1,17 @@
+- name: Install ntp
+  apt: pkg=ntp
+
+- name: Configure ntp
+  template: src=etc/ntp.conf.j2
+            dest=/etc/ntp.conf
+            owner=root group=root
+            mode=0644
+  register: r
+  notify:
+    - Restart ntp
+
+- name: Start ntp
+  service: name=ntp state=started
+  when: not r.changed
+
+- meta: flush_handlers
diff --git a/roles/common/templates/etc/iptables/services.j2 b/roles/common/templates/etc/iptables/services.j2
index 5243ae1..2a36932 100644
--- a/roles/common/templates/etc/iptables/services.j2
+++ b/roles/common/templates/etc/iptables/services.j2
@@ -4,13 +4,17 @@
 # direction              protocol     destination port            source port
 # (in|out|inout)[46]?    (tcp|udp|..) (port|port:port|port,port)  (port|port:port|port,port)
 
-inout   udp     500    500                              # ISAKMP
+inout   udp     500      500                            # ISAKMP
 #inout   udp     4500    4500    # IPSec NAT Traversal
 
 out     tcp     80,443                                  # HTTP/HTTPS
 out     udp     53                                      # DNS
 out     udp     67                                      # DHCP
 
+{% if 'NTP-master' in group_names %}
+out     udp     123      123                            # NTP
+{% endif %}
+
 in      tcp     {{ ansible_ssh_port|default('22') }}    # SSH
 {% if 'MX' in group_names %}
 in      tcp     25                                      # SMTP
diff --git a/roles/common/templates/etc/ntp.conf.j2 b/roles/common/templates/etc/ntp.conf.j2
new file mode 100644
index 0000000..2f70cef
--- /dev/null
+++ b/roles/common/templates/etc/ntp.conf.j2
@@ -0,0 +1,59 @@
+# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
+
+driftfile /var/lib/ntp/ntp.drift
+
+
+# Enable this if you want statistics to be logged.
+#statsdir /var/log/ntpstats/
+
+statistics loopstats peerstats clockstats
+filegen loopstats file loopstats type day enable
+filegen peerstats file peerstats type day enable
+filegen clockstats file clockstats type day enable
+
+
+# You do need to talk to an NTP server or two (or three).
+{% if 'NTP-master' in group_names %}
+# Use Stratum One Time Servers:
+# http://support.ntp.org/bin/view/Servers/StratumOneTimeServers
+server ntp1.sp.se         iburst
+server ntp2.sp.se         iburst
+server ntp2.gbg.netnod.se iburst
+server ntp1.sth.netnod.se iburst
+server ntp2.sth.netnod.se iburst
+{% else %}
+# Sychronize to our (stratum 2) NTP server through IPSec, to ensure our
+# network has a consistent time.
+server {{ NTP_master }} iburst
+{% endif %}
+
+
+# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
+# details.  The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
+# might also be helpful.
+#
+# Note that "restrict" applies to both servers and clients, so a configuration
+# that might be intended to block requests from certain clients could also end
+# up blocking replies from your own upstream servers.
+
+# By default, exchange time with everybody, but don't allow configuration.
+restrict -4 default kod notrap nomodify nopeer noquery
+restrict -6 default kod notrap nomodify nopeer noquery
+
+# Local users may interrogate the ntp server more closely.
+restrict 127.0.0.1
+restrict ::1
+
+# Clients from this (example!) subnet have unlimited access, but only if
+# cryptographically authenticated.
+#restrict 192.168.123.0 mask 255.255.255.0 notrust
+
+
+# If you want to provide time to your local subnet, change the next line.
+# (Again, the address is an example only.)
+#broadcast 192.168.123.255
+
+# If you want to listen to time broadcasts on your local subnet, de-comment the
+# next lines.  Please do this only if you trust everybody on the network!
+#disable auth
+#broadcastclient