(FACT-2746) Added cloud resolver

lib/facter/facts/linux/cloud.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Facts
+  module Linux
+    class Cloud
+      FACT_NAME = 'cloud'
+
+      def call_the_resolver
+        cloud_provider = Facter::Resolvers::Cloud.resolve(:cloud_provider)
+
+        Facter::ResolvedFact.new(FACT_NAME, cloud_provider)
+      end
+    end
+  end
+end

lib/facter/resolvers/cloud.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module Facter
+  module Resolvers
+    class Cloud < BaseResolver
+      # cloud_provider
+
+      @fact_list ||= {}
+
+      class << self
+        private
+
+        def post_resolve(fact_name)
+          @fact_list.fetch(fact_name) { detect_azure(fact_name) }
+        end
+
+        def detect_azure(fact_name)
+          search_dirs = %w[/var/lib/dhcp /var/lib/NetworkManager]
+          search_dirs.each do |path|
+            next unless File.directory?(path)
+
+            files = Dir.entries(path)
+            files.select! { |filename| filename =~ /^dhclient.*lease.*$/ }
+            files.each do |file|
+              path = File.join([path, file])
+              output = Util::FileHelper.safe_read(path)
+
+              if output.include?('option unknown-245') || output.include?('option 245')
+                @fact_list[:cloud_provider] = 'azure'
+                return @fact_list[fact_name]
+              end
+            end
+          end
+          nil
+        end
+      end
+    end
+  end
+end

spec/facter/resolvers/cloud_spec.rb

@@ -0,0 +1,79 @@
+# frozen_string_literal: true
+
+describe Facter::Resolvers::Cloud do
+  subject(:cloud_resolver) { Facter::Resolvers::Cloud }
+
+  let(:log_spy) { instance_spy(Facter::Log) }
+
+  before do
+    cloud_resolver.instance_variable_set(:@log, log_spy)
+    allow(File).to receive(:directory?)
+    allow(Dir).to receive(:entries)
+  end
+
+  after do
+    cloud_resolver.invalidate_cache
+  end
+
+  context 'when lease files are not found' do
+    before do
+      allow(File).to receive(:directory?).with('/var/lib/dhcp').and_return(true)
+      allow(Dir).to receive(:entries).with('/var/lib/dhcp').and_return('.')
+    end
+
+    it 'returns nil' do
+      expect(cloud_resolver.resolve(:cloud_provider)).to be_nil
+    end
+  end
+
+  context 'when lease file is found and contains option 245' do
+    let(:content) { load_fixture('dhclient_rhel_lease_8').read }
+
+    before do
+      allow(File).to receive(:directory?).with('/var/lib/dhcp').and_return(true)
+      allow(Facter::Util::FileHelper)
+        .to receive(:safe_read)
+        .with('/var/lib/dhcp/dhclient.rhel.lease.8')
+        .and_return(content)
+      allow(Dir).to receive(:entries).with('/var/lib/dhcp').and_return(['.', 'dhclient.rhel.lease.8'])
+    end
+
+    it 'returns azure' do
+      expect(cloud_resolver.resolve(:cloud_provider)).to eq('azure')
+    end
+  end
+
+  context 'when lease file is found without option 245' do
+    let(:content) { load_fixture('dhcp_lease').read }
+
+    before do
+      allow(File).to receive(:directory?).with('/var/lib/dhcp').and_return(true)
+      allow(Facter::Util::FileHelper)
+        .to receive(:safe_read)
+        .with('/var/lib/dhcp/dhclient.rhel.lease.8')
+        .and_return(content)
+      allow(Dir).to receive(:entries).with('/var/lib/dhcp').and_return(['.', 'dhclient.rhel.lease.8'])
+    end
+
+    it 'returns nil' do
+      expect(cloud_resolver.resolve(:cloud_provider)).to be_nil
+    end
+  end
+
+  context 'when lease file exists but not readable' do
+    let(:content) { '' }
+
+    before do
+      allow(File).to receive(:directory?).with('/var/lib/dhcp').and_return(true)
+      allow(Facter::Util::FileHelper)
+        .to receive(:safe_read)
+        .with('/var/lib/dhcp/dhclient.rhel.lease.8')
+        .and_return(content)
+      allow(Dir).to receive(:entries).with('/var/lib/dhcp').and_return(['.', 'dhclient.rhel.lease.8'])
+    end
+
+    it 'returns nil' do
+      expect(cloud_resolver.resolve(:cloud_provider)).to be_nil
+    end
+  end
+end

spec/fixtures/dhclient_rhel_lease_8

@@ -0,0 +1,39 @@
+default-duid "\000\004N&+>\315WL\311\2756\\\036P\3448\017";
+lease {
+  interface "eth0";
+  fixed-address 10.0.0.5;
+  server-name "AMS072031502021";
+  option subnet-mask 255.255.255.0;
+  option routers 10.0.0.1;
+  option dhcp-lease-time 4294967295;
+  option dhcp-message-type 5;
+  option domain-name-servers 168.63.129.16;
+  option dhcp-server-identifier 168.63.129.16;
+  option dhcp-renewal-time 4294967295;
+  option dhcp-rebinding-time 4294967295;
+  option unknown-245 a8:3f:81:10;
+  option rfc3442-classless-static-routes 0,10,0,0,1,32,168,63,129,16,10,0,0,1,32,169,254,169,254,10,0,0,1;
+  option domain-name "peq1diqrkypunc0cz32ezmxjye.ax.internal.cloudapp.net";
+  renew never;
+  rebind never;
+  expire never;
+}
+lease {
+  interface "eth0";
+  fixed-address 10.0.0.5;
+  server-name "AMS072031502021";
+  option subnet-mask 255.255.255.0;
+  option dhcp-lease-time 4294967295;
+  option routers 10.0.0.1;
+  option dhcp-message-type 5;
+  option dhcp-server-identifier 168.63.129.16;
+  option domain-name-servers 168.63.129.16;
+  option dhcp-renewal-time 4294967295;
+  option rfc3442-classless-static-routes 0,10,0,0,1,32,168,63,129,16,10,0,0,1,32,169,254,169,254,10,0,0,1;
+  option unknown-245 a8:3f:81:10;
+  option dhcp-rebinding-time 4294967295;
+  option domain-name "peq1diqrkypunc0cz32ezmxjye.ax.internal.cloudapp.net";
+  renew 0 2156/10/17 20:41:21;
+  rebind 0 2156/10/17 20:41:21;
+  expire 0 2156/10/17 20:41:21;
+}