Composable HA

This commit implements composable HA for the pacemaker profiles.
- Everytime a pacemaker resource gets included on a node,
  that node will add a node cluster property with the name of the resource
  (e.g. galera-role=true)
- Add a location rule constraint to force running the resource only
  on the nodes that have that property
- We also make sure that any pacemaker resource/property creation has a
  predefined number of tries (20 by default). The reason for this is
  that within composable HA, it might be possible to get "older CIB"
  errors when another node changed the CIB while we were doing an
  operation on it. Simply retrying fixes this.
- Also make sure that we use the newly introduced
  pacemaker::constraint::order class instead of the older
  pacemaker::constraint::base class. The former uses the push_cib()
  function and hence behaves correctly in case multiple nodes try
  to modify the CIB at the same time.

Change-Id: I63da4f48da14534fd76265764569e76300534472
Depends-On: Ib931adaff43dbc16220a90fb509845178d696402
Depends-On: I8d78cc1b14f0e18e034b979a826bf3cdb0878bae
Depends-On: Iba1017c33b1cd4d56a3ee8824d851b38cfdbc2d3

1 files changed, 40 insertions, 12 deletions

diff --git a/manifests/pacemaker/haproxy_with_vip.pp b/manifests/pacemaker/haproxy_with_vip.pp
index 0539beb..a27b94b 100644
--- a/manifests/pacemaker/haproxy_with_vip.pp
+++ b/manifests/pacemaker/haproxy_with_vip.pp
@@ -27,11 +27,35 @@
 #  (String) IP address on which HAProxy is colocated
 #  Required
 #
+# [*location_rule*]
+#  (optional) Add a location constraint before actually enabling
+#  the resource. Must be a hash like the following example:
+#  location_rule => {
+#    resource_discovery => 'exclusive',    # optional
+#    role               => 'master|slave', # optional
+#    score              => 0,              # optional
+#    score_attribute    => foo,            # optional
+#    # Multiple expressions can be used
+#    expression         => ['opsrole eq controller']
+#  }
+#  Defaults to undef
+#
+# [*pcs_tries*]
+#   (Optional) The number of times pcs commands should be retried.
+#   Defaults to 1
+#
 # [*ensure*]
 #  (Boolean) Create the all the resources only if true.  False won't
 #  destroy the resource, it will just not create them.
 #  Default to true
-define tripleo::pacemaker::haproxy_with_vip($vip_name, $ip_address, $ensure = true) {
+#
+define tripleo::pacemaker::haproxy_with_vip(
+  $vip_name,
+  $ip_address,
+  $location_rule = undef,
+  $pcs_tries     = 1,
+  $ensure        = true)
+{
   if($ensure) {
     if is_ipv6_address($ip_address) {
       $netmask = '64'
@@ -40,25 +64,29 @@ define tripleo::pacemaker::haproxy_with_vip($vip_name, $ip_address, $ensure = tr
     }
 
     pacemaker::resource::ip { "${vip_name}_vip":
-      ip_address   => $ip_address,
-      cidr_netmask => $netmask,
+      ip_address    => $ip_address,
+      cidr_netmask  => $netmask,
+      location_rule => $location_rule,
+      tries         => $pcs_tries,
     }
-    pacemaker::constraint::base { "${vip_name}_vip-then-haproxy":
-      constraint_type   => 'order',
+    pacemaker::constraint::order { "${vip_name}_vip-then-haproxy":
       first_resource    => "ip-${ip_address}",
       second_resource   => 'haproxy-clone',
       first_action      => 'start',
       second_action     => 'start',
       constraint_params => 'kind=Optional',
-      require           => [Pacemaker::Resource::Service['haproxy'],
-                            Pacemaker::Resource::Ip["${vip_name}_vip"]],
+      tries             => $pcs_tries,
     }
     pacemaker::constraint::colocation { "${vip_name}_vip-with-haproxy":
-      source  => "ip-${ip_address}",
-      target  => 'haproxy-clone',
-      score   => 'INFINITY',
-      require => [Pacemaker::Resource::Service['haproxy'],
-                  Pacemaker::Resource::Ip["${vip_name}_vip"]],
+      source => "ip-${ip_address}",
+      target => 'haproxy-clone',
+      score  => 'INFINITY',
+      tries  => $pcs_tries,
     }
+
+    Pacemaker::Resource::Ip["${vip_name}_vip"] ->
+      Pacemaker::Resource::Service['haproxy'] ->
+        Pacemaker::Constraint::Order["${vip_name}_vip-then-haproxy"] ->
+          Pacemaker::Constraint::Colocation["${vip_name}_vip-with-haproxy"]
   }
 }