Merge pull request #251 from agrare/network_interface_ip_output_json

Use --json for ip command output

Author: bdunne

lib/linux_admin/network_interface.rb

@@ -1,7 +1,8 @@
-require 'ipaddr'
-
 module LinuxAdmin
   class NetworkInterface
+    require "ipaddr"
+    require "json"
+
     # Cached class instance variable for what distro we are running on
     @dist_class = nil
 
@@ -60,14 +61,16 @@ def reload
         return false
       end
 
-      parse_ip4(ip_output)
-      parse_ip6(ip_output, :global)
-      parse_ip6(ip_output, :link)
+      addr_info = ip_output["addr_info"]
 
-      @network_conf[:mac] = parse_ip_output(ip_output, %r{link/ether}, 1)
+      parse_ip4(addr_info)
+      parse_ip6(addr_info, "global")
+      parse_ip6(addr_info, "link")
+
+      @network_conf[:mac] = ip_output["address"]
 
       [4, 6].each do |version|
-        @network_conf["gateway#{version}".to_sym] = parse_ip_output(ip_route(version), /^default/, 2)
+        @network_conf["gateway#{version}".to_sym] = ip_route(version, "default")&.dig("gateway")
       end
       true
     end
@@ -168,23 +171,15 @@ def stop
 
     private
 
-    # Parses the output of `ip addr show`
-    #
-    # @param output [String] The command output
-    # @param regex  [Regexp] Regular expression to match the desired output line
-    # @param col    [Fixnum] The whitespace delimited column to be returned
-    # @return [String] The parsed data
-    def parse_ip_output(output, regex, col)
-      the_line = output.split("\n").detect { |l| l =~ regex }
-      the_line.nil? ? nil : the_line.strip.split(' ')[col]
-    end
-
     # Runs the command `ip addr show <interface>`
     #
     # @return [String] The command output
     # @raise [NetworkInterfaceError] if the command fails
     def ip_show
-      Common.run!(Common.cmd("ip"), :params => ["addr", "show", @interface]).output
+      output = Common.run!(Common.cmd("ip"), :params => ["--json", "addr", "show", @interface]).output
+      return {} if output.blank?
+
+      JSON.parse(output).first
     rescue AwesomeSpawn::CommandResultError => e
       raise NetworkInterfaceError.new(e.message, e.result)
     end
@@ -194,35 +189,36 @@ def ip_show
     # @param version [Fixnum] Version of IP protocol (4 or 6)
     # @return [String] The command output
     # @raise [NetworkInterfaceError] if the command fails
-    def ip_route(version)
-      Common.run!(Common.cmd("ip"), :params => ["-#{version}", 'route']).output
+    def ip_route(version, route = "default")
+      output = Common.run!(Common.cmd("ip"), :params => ["--json", "-#{version}", "route", "show", route]).output
+      return {} if output.blank?
+
+      JSON.parse(output).first
     rescue AwesomeSpawn::CommandResultError => e
       raise NetworkInterfaceError.new(e.message, e.result)
     end
 
     # Parses the IPv4 information from the output of `ip addr show <device>`
     #
     # @param ip_output [String] The command output
-    def parse_ip4(ip_output)
-      cidr_ip = parse_ip_output(ip_output, /inet /, 1)
-      return unless cidr_ip
+    def parse_ip4(addr_info)
+      inet = addr_info&.detect { |addr| addr["family"] == "inet" }
+      return if inet.nil?
 
-      parts = cidr_ip.split('/')
-      @network_conf[:address] = parts[0]
-      @network_conf[:prefix] = parts[1].to_i
+      @network_conf[:address] = inet["local"]
+      @network_conf[:prefix]  = inet["prefixlen"]
     end
 
     # Parses the IPv6 information from the output of `ip addr show <device>`
     #
     # @param ip_output [String] The command output
     # @param scope     [Symbol] The IPv6 scope (either `:global` or `:local`)
-    def parse_ip6(ip_output, scope)
-      cidr_ip = parse_ip_output(ip_output, /inet6 .* scope #{scope}/, 1)
-      return unless cidr_ip
+    def parse_ip6(addr_info, scope)
+      inet6 = addr_info&.detect { |addr| addr["family"] == "inet6" && addr["scope"] == scope }
+      return if inet6.nil?
 
-      parts = cidr_ip.split('/')
-      @network_conf["address6_#{scope}".to_sym] = parts[0]
-      @network_conf["prefix6_#{scope}".to_sym] = parts[1].to_i
+      @network_conf["address6_#{scope}".to_sym] = inet6["local"]
+      @network_conf["prefix6_#{scope}".to_sym]  = inet6["prefixlen"]
     end
   end
 end

spec/network_interface_spec.rb

@@ -56,10 +56,10 @@
 
   context "on all systems" do
     let(:ip_link_args)      { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[--json link]}] }
-    let(:ip_show_eth0_args) { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[addr show eth0]}] }
-    let(:ip_show_lo_args)   { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[addr show lo]}] }
-    let(:ip_route_args)     { [LinuxAdmin::Common.cmd("ip"),     {:params => ['-4', 'route']}] }
-    let(:ip6_route_args)    { [LinuxAdmin::Common.cmd("ip"),     {:params => ['-6', 'route']}] }
+    let(:ip_show_eth0_args) { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[--json addr show eth0]}] }
+    let(:ip_show_lo_args)   { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[--json addr show lo]}] }
+    let(:ip_route_args)     { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[--json -4 route show default]}] }
+    let(:ip6_route_args)    { [LinuxAdmin::Common.cmd("ip"),     {:params => %w[--json -6 route show default]}] }
     let(:ifup_args)         { [LinuxAdmin::Common.cmd("ifup"),   {:params => ["eth0"]}] }
     let(:ifdown_args)       { [LinuxAdmin::Common.cmd("ifdown"), {:params => ["eth0"]}] }
     let(:ip_link_out) do
@@ -69,53 +69,32 @@
     end
     let(:ip_addr_eth0_out) do
       <<~IP_OUT
-        2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
-            link/ether 00:0c:29:ed:0e:8b brd ff:ff:ff:ff:ff:ff
-            inet 192.168.1.9/24 brd 192.168.1.255 scope global dynamic eth0
-               valid_lft 1297sec preferred_lft 1297sec
-            inet6 fe80::20c:29ff:feed:e8b/64 scope link
-               valid_lft forever preferred_lft forever
-            inet6 fd12:3456:789a:1::1/96 scope global
-               valid_lft forever preferred_lft forever
+        [{"ifindex":2,"ifname":"eth0","flags":["BROADCAST","MULTICAST","UP","LOWER_UP"],"mtu":1500,"qdisc":"fq_codel","operstate":"UP","group":"default","txqlen":1000,"link_type":"ether","address":"00:0c:29:ed:0e:8b","broadcast":"ff:ff:ff:ff:ff:ff","altnames":["enp0s2","ens2"],"addr_info":[{"family":"inet","local":"192.168.1.9","prefixlen":24,"broadcast":"192.168.255","scope":"global","noprefixroute":true,"label":"eth0","valid_life_time":4294967295,"preferred_life_time":4294967295},{"family":"inet6","local":"fe80::20c:29ff:feed:e8b","prefixlen":64,"scope":"link","noprefixroute":true,"valid_life_time":"forever","preferred_life_time":"forever"},{"family":"inet6","local":"fd12:3456:789a:1::1","prefixlen":96,"scope":"global","noprefixroute":true,"valid_life_time":"forever","preferred_life_time":"forever"}]}]
       IP_OUT
     end
     let(:ip_addr_lo_out) do
       <<~IP_OUT
-        1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
-            link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
-            inet 127.0.0.1/8 scope host lo
-               valid_lft forever preferred_lft forever
-            inet6 ::1/128 scope host
-               valid_lft forever preferred_lft forever
+        [{"ifindex":1,"ifname":"lo","flags":["LOOPBACK","UP","LOWER_UP"],"mtu":65536,"qdisc":"noqueue","operstate":"UNKNOWN","group":"default","txqlen":1000,"link_type":"loopback","address":"00:00:00:00:00:00","broadcast":"00:00:00:00:00:00","addr_info":[{"family":"inet","local":"127.0.0.1","prefixlen":8,"scope":"host","label":"lo","valid_life_time":4294967295,"preferred_life_time":4294967295},{"family":"inet6","local":"::1","prefixlen":128,"scope":"host","valid_life_time":"forever","preferred_life_time":"forever"}]}]
       IP_OUT
     end
     let(:ip6_addr_out) do
       <<~IP_OUT
-        2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
-            link/ether 00:0c:29:ed:0e:8b brd ff:ff:ff:ff:ff:ff
-            inet6 fe80::20c:29ff:feed:e8b/64 scope link
-               valid_lft forever preferred_lft forever
-            inet6 fd12:3456:789a:1::1/96 scope global
-               valid_lft forever preferred_lft forever
+        [{"ifindex":2,"ifname":"eth0","flags":["BROADCAST","MULTICAST","UP","LOWER_UP"],"mtu":1500,"qdisc":"fq_codel","operstate":"UP","group":"default","txqlen":1000,"link_type":"ether","address":"00:0c:29:ed:0e:8b","broadcast":"ff:ff:ff:ff:ff:ff","altnames":["enp0s2","ens2"],"addr_info":[{"family":"inet6","local":"fe80::20c:29ff:feed:e8b","prefixlen":64,"scope":"link","noprefixroute":true,"valid_life_time":"forever","preferred_life_time":"forever"},{"family":"inet6","local":"fd12:3456:789a:1::1","prefixlen":96,"scope":"global","noprefixroute":true,"valid_life_time":"forever","preferred_life_time":"forever"}]}]
       IP_OUT
     end
     let(:ip_route_out) do
       <<~IP_OUT
-        default via 192.168.1.1 dev eth0  proto static  metric 100
-        192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.9  metric 100
+        [{"dst":"default","gateway":"192.168.1.1","dev":"eth0","protocol":"static","metric":100,"flags":[]}]
       IP_OUT
     end
     let(:ip6_route_out) do
       <<~IP_OUT
-        default via d:e:a:d:b:e:e:f dev eth0  proto static  metric 100
-        fc00:dead:beef:a::/64 dev virbr1  proto kernel  metric 256 linkdown  pref medium
-        fe80::/64 dev eth0  proto kernel  scope link metric 100
+        [{"dst":"default","gateway":"d:e:a:d:b:e:e:f","dev":"eth0","protocol":"static","metric":100,"flags":[]}]
       IP_OUT
     end
     let(:ip_none_addr_out) do
       <<~IP_OUT
-        2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel master virbr1 state DOWN group default qlen 1000
-            link/ether 52:54:00:ce:b4:f4 brd ff:ff:ff:ff:ff:ff
+        [{"ifindex":2,"ifname":"eth0","flags":["BROADCAST","MULTICAST","UP","LOWER_UP"],"mtu":1500,"qdisc":"fq_codel","operstate":"UP","group":"default","txqlen":1000,"link_type":"ether","address":"00:0c:29:ed:0e:8b","broadcast":"ff:ff:ff:ff:ff:ff","altnames":["enp0s2","ens2"],"addr_info":[]}]
       IP_OUT
     end