Merge pull request #4564 from wtsi-hgi/fix/4551-openstack-builder-reuse-ips

add reuse_ips option for openstack builder

builder/openstack/builder.go

@@ -102,6 +102,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepAllocateIp{
 			FloatingIpPool: b.config.FloatingIpPool,
 			FloatingIp:     b.config.FloatingIp,
+			ReuseIps:       b.config.ReuseIps,
 		},
 		&communicator.StepConnect{
 			Config: &b.config.RunConfig.Comm,

builder/openstack/run_config.go

@@ -23,6 +23,7 @@ type RunConfig struct {
 	RackconnectWait  bool              `mapstructure:"rackconnect_wait"`
 	FloatingIpPool   string            `mapstructure:"floating_ip_pool"`
 	FloatingIp       string            `mapstructure:"floating_ip"`
+	ReuseIps         bool              `mapstructure:"reuse_ips"`
 	SecurityGroups   []string          `mapstructure:"security_groups"`
 	Networks         []string          `mapstructure:"networks"`
 	UserData         string            `mapstructure:"user_data"`

builder/openstack/step_allocate_ip.go

@@ -13,6 +13,7 @@ import (
 type StepAllocateIp struct {
 	FloatingIpPool string
 	FloatingIp     string
+	ReuseIps       bool
 }
 
 func (s *StepAllocateIp) Run(state multistep.StateBag) multistep.StepAction {
@@ -37,8 +38,9 @@ func (s *StepAllocateIp) Run(state multistep.StateBag) multistep.StepAction {
 	if s.FloatingIp != "" {
 		instanceIp.IP = s.FloatingIp
 	} else if s.FloatingIpPool != "" {
-		// If we have a free floating IP in the pool, use it first
+		// If ReuseIps is set to true and we have a free floating IP in
-		// rather than creating one
+		// the pool, use it first rather than creating one
+		if s.ReuseIps {
 			ui.Say(fmt.Sprintf("Searching for unassociated floating IP in pool %s", s.FloatingIpPool))
 			pager := floatingips.List(client)
 			err := pager.EachPage(func(page pagination.Page) (bool, error) {
@@ -68,6 +70,7 @@ func (s *StepAllocateIp) Run(state multistep.StateBag) multistep.StepAction {
 				ui.Error(err.Error())
 				return multistep.ActionHalt
 			}
+		}
 
 		if instanceIp.IP == "" {
 			ui.Say(fmt.Sprintf("Creating floating IP..."))

website/source/docs/builders/openstack.html.md

@@ -122,6 +122,13 @@ builder.
     launch the server to create the AMI. If not specified, Packer will use the
     environment variable `OS_REGION_NAME`, if set.
 
+-   `reuse_ips` (boolean) - Whether or not to attempt to reuse existing
+    unassigned floating ips in the project before allocating a new one. Note
+    that it is not possible to safely do this concurrently, so if you are
+    running multiple openstack builds concurrently, or if other processes are
+    assigning and using floating IPs in the same openstack project while packer
+    is running, you should not set this to true. Defaults to false.
+
 -   `security_groups` (array of strings) - A list of security groups by name to
     add to this instance.