Added IpoibMode as suggested in CR.

src/lib/y2network/connection_config/infiniband.rb

@@ -25,13 +25,8 @@ module ConnectionConfig
     #
     # @see https://www.kernel.org/doc/Documentation/infiniband/ipoib.txt
     class Infiniband < Base
-      # @return [String] transport mode ("datagram" or "connected")
+      # @return [IpoibMode] transport mode
       attr_accessor :ipoib_mode
-
-      # Constructor
-      def initialize
-        @ipoib_mode = ""
-      end
     end
   end
 end

src/lib/y2network/ipoib_mode.rb

@@ -0,0 +1,60 @@
+# Copyright (c) [2019] SUSE LLC
+#
+# All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of version 2 of the GNU General Public License as published
+# by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, contact SUSE LLC.
+#
+# To contact SUSE LLC about this file by physical or electronic mail, you may
+# find current contact information at www.suse.com.
+
+require "yast"
+
+module Y2Network
+  # This class represents the supported IPoIB transport modes.
+  class IpoibMode
+    class << self
+      # Returns all the existing modes
+      #
+      # @return [Array<IpoibMode>]
+      def all
+        @all ||= IpoibMode.constants
+                          .map { |c| IpoibMode.const_get(c) }
+                          .select { |c| c.is_a?(IpoibMode) }
+      end
+
+      # Returns the transport mode with a given name
+      #
+      # @param name [String]
+      # @return [IpoibMode,nil] Ipoib mode or nil if not found
+      def from_name(name)
+        all.find { |t| t.name == name }
+      end
+    end
+
+    # @return [String] Returns mode name
+    attr_reader :name
+
+    # Constructor
+    #
+    # @param name [String] mode name
+    def initialize(name)
+      @name = name
+    end
+
+    DATAGRAM = new("datagram")
+    CONNECTED = new("connected")
+    # Not a mode at all but the default value that will be choose by the IB
+    # driver (bnc#1086454)
+    DEFAULT = new("")
+  end
+end

src/lib/y2network/sysconfig/connection_config_readers/infiniband.rb

@@ -18,6 +18,7 @@
 # find current contact information at www.suse.com.
 
 require "y2network/sysconfig/connection_config_readers/base"
+require "y2network/ipoib_mode"
 
 module Y2Network
   module Sysconfig
@@ -29,7 +30,7 @@ class Infiniband < Base
 
         # @see Y2Network::Sysconfig::ConnectionConfigReaders::Base#update_connection_config
         def update_connection_config(conn)
-          conn.ipoib_mode = file.ipoib_mode
+          conn.ipoib_mode = IpoibMode.from_name(file.ipoib_mode.to_s)
         end
       end
     end

src/lib/y2network/sysconfig/connection_config_writers/infiniband.rb

@@ -29,7 +29,7 @@ class Infiniband < Base
 
         # @see Y2Network::ConnectionConfigWriters::Base#update_file
         def update_file(conn)
-          file.ipoib_mode = conn.ipoib_mode
+          file.ipoib_mode = conn.ipoib_mode.name
         end
       end
     end

test/y2network/sysconfig/connection_config_readers/infiniband_test.rb

@@ -41,7 +41,7 @@
     it "returns a infiniband connection config object" do
       infiniband_conn = handler.connection_config
       expect(infiniband_conn.interface).to eq("ib0")
-      expect(infiniband_conn.ipoib_mode).to eq("datagram")
+      expect(infiniband_conn.ipoib_mode).to eq(Y2Network::IpoibMode::DATAGRAM)
       expect(infiniband_conn.ip_configs.map(&:address)).to eq([ip_address])
       expect(infiniband_conn.bootproto).to eq(Y2Network::BootProtocol::STATIC)
     end

test/y2network/sysconfig/connection_config_writers/infiniband_test.rb

@@ -22,6 +22,7 @@
 require "y2network/sysconfig/connection_config_writers/infiniband"
 require "y2network/startmode"
 require "y2network/boot_protocol"
+require "y2network/ipoib_mode"
 require "y2network/connection_config/infiniband"
 require "y2network/connection_config/ip_config"
 
@@ -58,7 +59,7 @@ def file_content(scr_root, file)
       name:        "ib0",
       interface:   "ib0",
       description: "",
-      ipoib_mode:  "datagram",
+      ipoib_mode:  Y2Network::IpoibMode::CONNECTED,
       ip_configs:  ip_configs,
       startmode:   Y2Network::Startmode.create("auto"),
       bootproto:   Y2Network::BootProtocol::STATIC
@@ -71,7 +72,7 @@ def file_content(scr_root, file)
     it "writes the 'ipoib_mode' attribute" do
       handler.write(conn)
       expect(file).to have_attributes(
-        ipoib_mode: "datagram"
+        ipoib_mode: "connected"
       )
     end
   end