Add get_default_gateways() parser function

for getting list of default gateways. This list ordered by
gateway_metric.

Change-Id: I36e6c63293992331df6e3f07c6738ceaa2cb4dd7
related-blueprint: templates-for-networking

deployment/puppet/l23network/lib/puppet/parser/functions/get_default_gateways.rb

@@ -0,0 +1,44 @@
+require 'ipaddr'
+begin
+  require 'puppet/parser/functions/lib/prepare_cidr.rb'
+rescue LoadError => e
+  # puppet apply does not add module lib directories to the $LOAD_PATH (See
+  # #4248). It should (in the future) but for the time being we need to be
+  # defensive which is what this rescue block is doing.
+  rb_file = File.join(File.dirname(__FILE__),'lib','prepare_cidr.rb')
+  load rb_file if File.exists?(rb_file) or raise e
+end
+require 'puppetx/l23_network_scheme'
+
+Puppet::Parser::Functions::newfunction(:get_default_gateways, :type => :rvalue, :doc => <<-EOS
+    Parse network_scheme and return list of default gateways,
+    ordered by its metrics
+
+    Returns [] if no gateways.
+
+    EOS
+  ) do |argv|
+
+  cfg = L23network::Scheme.get_config(lookupvar('l3_fqdn_hostname'))
+  if cfg.nil?
+    raise(Puppet::ParseError, "get_default_gateways(): You must call prepare_network_config(...) first!")
+  end
+
+  endpoints = cfg[:endpoints]
+  if ! endpoints.is_a? Hash
+      Puppet::ParseError("get_default_gateways(): Section 'endpoints' should be a hash.")
+  end
+
+  rv = []
+  endpoints.each do |ep_name, ep_props|
+    next if ep_props[:gateway].nil?
+    rv << {
+      :m  => (ep_props[:gateway_metric] or 0),
+      :g => ep_props[:gateway]
+    }
+  end
+  return [] if rv.empty?
+  rv.sort_by{|a| a[:m]}.map{|t| t[:g]}
+end
+
+# vim: set ts=2 sw=2 et :

deployment/puppet/l23network/spec/functions/get_default_gateways__spec.rb

@@ -0,0 +1,73 @@
+require 'spec_helper'
+require 'yaml'
+require 'puppetx/l23_hash_tools'
+
+describe Puppet::Parser::Functions.function(:get_default_gateways) do
+let(:network_scheme) do
+<<eof
+---
+  version: 1.1
+  provider: lnx
+  interfaces:
+    eth0:
+      mtu: 2048
+    eth1:
+      mtu: 999
+    eth2: {}
+    eth3: {}
+    eth4: {}
+    eth5: {}
+    eth44: {}
+  endpoints:
+    eth0:
+      IP: 'none'
+    eth4:
+      IP: 'none'
+    br-ex:
+      gateway: 10.1.3.1
+      IP:
+        - '10.1.3.11/24'
+    br-mgmt:
+      gateway: 10.1.1.1
+      gateway_metric: 20
+      IP:
+        - '10.1.1.11/24'
+    br-storage:
+      gateway: 10.1.2.1
+      gateway_metric: 10
+      IP:
+        - '10.1.2.11/24'
+    br-floating:
+      IP: none
+eof
+end
+
+
+
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  subject do
+    function_name = Puppet::Parser::Functions.function(:get_default_gateways)
+    scope.method(function_name)
+  end
+
+  context ":get_default_gateways() usage" do
+    before(:each) do
+      scope.stubs(:lookupvar).with('l3_fqdn_hostname').returns('node1.tld')
+      L23network::Scheme.set_config(
+        scope.lookupvar('l3_fqdn_hostname'),
+        L23network.sanitize_keys_in_hash(YAML.load(network_scheme))
+      )
+    end
+
+    it 'should exist' do
+      subject == Puppet::Parser::Functions.function(:get_default_gateways)
+    end
+
+    it do
+      should run.with_params().and_return(['10.1.3.1', '10.1.2.1', '10.1.1.1'])
+    end
+
+  end
+
+end