Allow specifying the gateway_external_network by name

This change makes the l3_agent recipe lookup the ID of the network used
for the gateway external network by name.  For example, specify

node[openstack][network][l3][gateway_external_network_name] = public

and the recipe will lookup the network by name.  It will use
openstack-common/libraries/cli.rb network_uuid method, effectively
querying `neutron net-external-list`.  The result is saved to
gateway_external_network_id and used on subsequent runs.

To have the recipe check the UUID again (e.g. to update it), reset the
_id attribute to nil.

Change-Id: I5df6f9989df7b18121a8050835a192da9e1a762e

CHANGELOG.md

@@ -7,8 +7,8 @@ This file is used to list changes made in each version of cookbook-openstack-net
 * Add attribute for ML2 enable_ipset
 * Bump Chef gem to 11.16
 * Add attributes for api_workers and rpc_workers
-
 * Add attributes for quota_router and quota_floatingip
+* Allow specifying the L3 agents' gateway_external_network by name.
 
 ## 10.0.1
 * Add tunnel_types item in ovs_neutron_plugin.ini.erb

attributes/default.rb

@@ -352,6 +352,8 @@ default['openstack']['network']['l3']['router_id'] = nil
 # the agent will enforce that only a single external networks exists and
 # use that external network id
 default['openstack']['network']['l3']['gateway_external_network_id'] = nil
+# If this name is specified and the ID above is nil, it will be looked up.
+default['openstack']['network']['l3']['gateway_external_network_name'] = nil
 
 # Indicates that this L3 agent should also handle routers that do not have
 # an external network gateway configured.  This option should be True only

recipes/l3_agent.rb

@@ -22,6 +22,28 @@
 
 include_recipe 'openstack-network::common'
 
+ruby_block 'query gateway external network uuid' do
+  block do
+    begin
+      external_name = node['openstack']['network']['l3']['gateway_external_network_name']
+      admin_user = node['openstack']['identity']['admin_user']
+      admin_tenant = node['openstack']['identity']['admin_tenant_name']
+      env = openstack_command_env admin_user, admin_tenant
+
+      external_id = network_uuid 'net-external', 'name', external_name, env
+      Chef::Log.error("gateway external network UUID for #{external_name} not found.") if external_id.nil?
+      node.set['openstack']['network']['l3']['gateway_external_network_id'] = external_id
+    rescue RuntimeError => e
+      Chef::Log.error("Could not query UUID for network #{external_name}. Error was #{e.message}") unless external_id
+    end
+  end
+  action :run
+  only_if do
+    node['openstack']['network']['l3']['gateway_external_network_id'].nil? &&
+    node['openstack']['network']['l3']['gateway_external_network_name']
+  end
+end
+
 platform_options = node['openstack']['network']['platform']
 core_plugin = node['openstack']['network']['core_plugin']
 main_plugin = node['openstack']['network']['core_plugin_map'][core_plugin.split('.').last.downcase]

spec/l3_agent_spec.rb

@@ -33,6 +33,24 @@ describe 'openstack-network::l3_agent' do
       expect(chef_run).to upgrade_package('neutron-l3-agent')
     end
 
+    describe 'gateway_external_network_id' do
+      before do
+        node.set['openstack']['network']['l3']['gateway_external_network_name'] = 'public'
+      end
+
+      it 'looks up and sets the id attribute if needed' do
+        node.set['openstack']['network']['l3']['gateway_external_network_id'] = nil
+        chef_run.ruby_block('query gateway external network uuid').old_run_action(:create)
+        expect(chef_run.node['openstack']['network']['l3']['gateway_external_network_id']).to eq '000-NET-UUID-FROM-CLI'
+      end
+
+      it 'uses the id attribute if it is already set' do
+        node.set['openstack']['network']['l3']['gateway_external_network_id'] = '000-NET-UUID-ALREADY-SET'
+        chef_run.ruby_block('query gateway external network uuid').old_run_action(:create)
+        expect(chef_run.node['openstack']['network']['l3']['gateway_external_network_id']).to eq '000-NET-UUID-ALREADY-SET'
+      end
+    end
+
     describe 'l3_agent.ini' do
       let(:file) { chef_run.template('/etc/neutron/l3_agent.ini') }
 

spec/spec_helper.rb

@@ -99,6 +99,9 @@ shared_context 'neutron-stubs' do
     allow_any_instance_of(Chef::Resource::RubyBlock).to receive(:identity_uuid)
       .with('tenant', 'name', 'service', {})
       .and_return('000-UUID-FROM-CLI')
+    allow_any_instance_of(Chef::Resource::RubyBlock).to receive(:network_uuid)
+      .with('net-external', 'name', 'public', {})
+      .and_return('000-NET-UUID-FROM-CLI')
 
     stub_command('dpkg -l | grep openvswitch-switch | grep 1.10.2-1').and_return(true)
     stub_command('ovs-vsctl br-exists br-int').and_return(false)