Network: Add support for parsing multipath routing (#1736)routes_17

Signed-off-by: Anita Zhang <the.anitazha@gmail.com>

2 files changed, 55 insertions, 2 deletions

diff --git a/lib/ohai/plugins/linux/network.rb b/lib/ohai/plugins/linux/network.rb
index 01380336..769f375f 100644
--- a/lib/ohai/plugins/linux/network.rb
+++ b/lib/ohai/plugins/linux/network.rb
@@ -80,9 +80,22 @@ Ohai.plugin(:Network) do
       line.strip!
       logger.trace("Plugin Network: Parsing #{line}")
       if /\\/.match?(line)
+        # If we have multipath routing, then the first part will be a normal
+        # looking route:
+        #   default proto ra metric 1024 <other options>
+        # Each successive part after that is a hop without those options.
+        # So the first thing we do is grab that first part, and split it into
+        # the route destination ("default"), and the route options.
         parts = line.split("\\")
-        route_dest = parts.shift.strip
-        route_endings = parts
+        route_dest, dest_opts = parts.first.split(nil, 2)
+        # Then all the route endings, generally just nexthops.
+        route_endings = parts[1..]
+        if dest_opts && !dest_opts.empty?
+          # Route options like proto, metric, etc. only appear once for each
+          # multipath configuration. Prepend this information to the route
+          # endings so the code below will assign the fields properly.
+          route_endings.map! { |e| e.include?("nexthop") ? "#{dest_opts} #{e}" : e }
+        end
       elsif line =~ /^([^\s]+)\s(.*)$/
         route_dest = $1
         route_endings = [$2]
diff --git a/spec/unit/plugins/linux/network_spec.rb b/spec/unit/plugins/linux/network_spec.rb
index 16c6f235..8dedf327 100644
--- a/spec/unit/plugins/linux/network_spec.rb
+++ b/spec/unit/plugins/linux/network_spec.rb
@@ -1219,6 +1219,46 @@ describe Ohai::System, "Linux Network Plugin" do
         end
       end
 
+      describe "when there're multipath routes" do
+        let(:linux_ip_route) do
+          <<~EOM
+            10.5.4.0/24 proto static \\ nexthop via 10.5.4.1 dev eth0 weight 1\\ nexthop via 10.5.4.2 dev eth0 weight 1
+          EOM
+        end
+
+        let(:linux_ip_route_inet6) do
+          <<~EOM
+            default proto ra metric 1024 expires 1797sec \\        nexthop via fe80::c018:50ff:fe41:ca33 dev eth0.11 weight 1 \\        nexthop via fe80::c018:50ff:fe41:ca33 dev eth0 weight 1 pref medium
+            default proto ra metric 1050 expires 1796sec \\        nexthop via fe80::c018:50ff:fe3f:9184 dev eth3 weight 1 \\        nexthop via fe80::c018:50ff:fe3f:9184 dev eth13 weight 1 pref medium
+          EOM
+        end
+
+        before do
+          plugin.run
+        end
+
+        it "completes the run" do
+          expect(plugin.logger).not_to receive(:trace).with(/Plugin linux::network threw exception/)
+          expect(plugin["network"]).not_to be_nil
+        end
+
+        it "sets default ipv6 interface and gateway" do
+          expect(plugin["network"]["default_inet6_interface"]).to eq("eth0")
+          expect(plugin["network"]["default_inet6_gateway"]).to eq("fe80::c018:50ff:fe41:ca33")
+        end
+
+        it "sets the routes properly" do
+          expect(plugin["network"]["interfaces"]["eth0"]["routes"]).to eq([
+            Mash.new( destination: "10.5.4.0/24", family: "inet", proto: "static", via: "10.5.4.1" ),
+            Mash.new( destination: "10.5.4.0/24", family: "inet", proto: "static", via: "10.5.4.2" ),
+            Mash.new( destination: "default", family: "inet6", proto: "ra", via: "fe80::c018:50ff:fe41:ca33", metric: "1024" ),
+          ])
+          expect(plugin["network"]["interfaces"]["eth0.11"]["routes"]).to eq([Mash.new( destination: "default", family: "inet6", proto: "ra", via: "fe80::c018:50ff:fe41:ca33", metric: "1024" )])
+          expect(plugin["network"]["interfaces"]["eth13"]["routes"]).to eq([Mash.new( destination: "default", family: "inet6", proto: "ra", via: "fe80::c018:50ff:fe3f:9184", metric: "1050" )])
+          expect(plugin["network"]["interfaces"]["eth3"]["routes"]).to eq([Mash.new( destination: "default", family: "inet6", proto: "ra", via: "fe80::c018:50ff:fe3f:9184", metric: "1050" )])
+        end
+      end
+
       describe "when there's a source field in a local route entry but it isnt in the default route" do
         let(:linux_ip_route) do
           <<~EOM