make node buffer configurable

node/lib/openshift-origin-node/model/node.rb

@@ -44,6 +44,7 @@ class Node < Model
       DEFAULT_QUOTA_FILES          = '80000'
       DEFAULT_NO_OVERCOMMIT_ACTIVE = false
       DEFAULT_MAX_ACTIVE_GEARS     = 0
+      DEFAULT_NODE_DF_BUFFER       = 0.05
 
       @@resource_limits_cache = nil
 
@@ -336,6 +337,8 @@ def self.node_utilization
 
         # use max_{active_,}gears if set in resource limits, or fall back to old "apps" names
         res['max_active_gears'] = (resource.get('max_active_gears') or resource.get('max_active_apps') or DEFAULT_MAX_ACTIVE_GEARS)
+        res['node_df_buffer'] = resource.get('node_df_buffer', DEFAULT_NODE_DF_BUFFER)
+
 
         #
         # Count number of git repos and gear status counts

plugins/msg-broker/mcollective/conf/openshift-origin-msg-broker-mcollective.conf.example

@@ -39,3 +39,7 @@ NODE_RSYNC_ADDRESS="ip_address"
 # can be moved if a gear is over quota limits, up to this quota multiplier.
 QUOTA_BLOCKS_BUFFER=1.2
 QUOTA_INODES_BUFFER=1.2
+
+# Node disk free space buffer.  This will ensure that gears will only be moved to
+# nodes that will have at least this amount of free disk space buffer after the move.
+NODE_DF_BUFFER=0.05

plugins/msg-broker/mcollective/config/initializers/openshift-origin-msg-broker-mcollective.rb

@@ -39,7 +39,8 @@
       :node_profile_enabled => conf.get_bool("NODE_PROFILE_ENABLED", "false"),
       :node_rsync_address => conf.get("NODE_RSYNC_ADDRESS", "ip_address"),
       :quota_blocks_buffer => conf.get("QUOTA_BLOCKS_BUFFER", 1.2),
-      :quota_inodes_buffer => conf.get("QUOTA_INODES_BUFFER", 1.2)
+      :quota_inodes_buffer => conf.get("QUOTA_INODES_BUFFER", 1.2),
+      :node_df_buffer => conf.get("NODE_DF_BUFFER", 0.05)
     }
   end
 end

plugins/msg-broker/mcollective/lib/openshift/mcollective_application_container_proxy.rb

@@ -39,6 +39,8 @@ def initialize(id, district=nil, blocks_multiplier=1, inodes_multiplier=1)
       inodes_multiplier=Rails.configuration.msg_broker[:quota_inodes_buffer]
       @blocks_multiplier = blocks_multiplier
       @inodes_multiplier = inodes_multiplier
+      node_df_buffer=Rails.configuration.msg_broker[:node_df_buffer]
+      @node_df_buffer = node_df_buffer
       @id = id
       @district = district
       @disable_print_debug = false
@@ -816,6 +818,20 @@ def get_node_total_size
       rpc_get_fact_direct('node_total_size').to_i
     end
 
+    # <<accessor>>
+    # Get the disk free buffer of a Node
+    #
+    # RETURNS:
+    # * Float: the disk free buffer of a Node
+    #
+    # NOTES:
+    # * method on Node
+    # * calls rpc_get_fact_direct
+    #
+    def get_node_df_buffer
+      rpc_get_fact_direct('node_df_buffer').to_f
+    end
+
     #
     # Add a component to an existing gear on the node
     #
@@ -2413,11 +2429,13 @@ def rsync_destination_container(gear, destination_container, destination_distric
       log_debug "DEBUG: Gear platform is '#{platform}'"
       destination_avail_space = destination_container.get_node_disk_free
       destination_total_space = destination_container.get_node_total_size
+      destination_df_buffer = destination_container.get_node_df_buffer
 
       # check here to make sure addition of gear to destination_container
       # will not result in > 95% full destination_container
-      if (destination_avail_space - source_used_blocks.to_f)/destination_total_space < 0.05
-        raise OpenShift::NodeUnavailableException.new("Gear '#{gear.uuid}' cannot be moved to '#{destination_container.id}'.  Not enough disk space, node would be > 95% full after move.", 140)
+      if (destination_avail_space - source_used_blocks.to_f)/destination_total_space < destination_df_buffer
+        max_value = sprintf('%.0f', (1.0 - destination_df_buffer)*100)
+        raise OpenShift::NodeUnavailableException.new("Gear '#{gear.uuid}' cannot be moved to '#{destination_container.id}'.  Not enough disk space, node would be using > #{max_value}% of it's disk space after the move.", 140)
       end
 
       log_debug "DEBUG: Creating new account for gear '#{gear.uuid}' on #{destination_container.id}"

plugins/msg-node/mcollective/facts/openshift_facts.rb

@@ -53,6 +53,7 @@ def get_node_config_value(key, default)
 Facter.add(:node_disk_free) { setcode { results['node_disk_free'] } }
 Facter.add(:node_total_size) { setcode { results['node_total_size'] } }
 Facter.add(:node_profile) { setcode { results['node_profile'] } }
+Facter.add(:node_df_buffer) { setcode { results['node_df_buffer'] } }
 Facter.add(:max_active_gears) { setcode { results['max_active_gears'] || '0' } }
 Facter.add(:no_overcommit_active) { setcode { results['no_overcommit_active'] || false } }
 Facter.add(:quota_blocks) { setcode { results['quota_blocks'] } }