add mdadm_arrays fact

lib/facter/mdadm_arrays.rb

@@ -0,0 +1,36 @@
+Facter.add('mdadm_arrays') do
+  mdadm = Facter.value(:mdadm)
+
+  setcode do
+    if mdadm.nil?
+      next nil
+    end 
+
+    cmd = "#{mdadm} --detail --scan"
+    output = Facter::Util::Resolution.exec(cmd)
+    if output.nil?
+      Facter.debug "#{cmd} returned no output"
+      next nil
+    end
+
+    # example line:
+    # ARRAY /dev/md1 metadata=1.1 name=foo.example.com:1 UUID=cad4da8b:418b3a4b:d27bad88:bb505b62
+
+    md = []
+    output.split(/\n/).each do |line|
+      Facter.debug "parsing line: #{line}"
+      next if line =~ /^\s+/ # white space only (may not be needed)
+      device = line.split(/\s+/)[1]
+      if device =~ /\S+/
+        Facter.debug "found device: #{device}"
+        md << device
+      end
+    end
+
+    if md.length > 0
+      next md.sort.join(',')
+    else
+      next nil
+    end
+  end
+end

spec/unit/facts/mdadm_arrays_spec.rb

@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+describe 'mdadm_arrays', :type => :fact do
+  before(:each) { Facter.clear }
+
+  context 'mdadm fact => /sbin/madam' do
+    context 'with no configured arrays' do
+      it 'should not find any' do
+        Facter.fact(:mdadm).stubs(:value).returns('/sbin/mdadm')
+        Facter::Util::Resolution.stubs(:exec).
+          with('/sbin/mdadm --detail --scan').
+          returns(nil)
+
+        Facter.fact(:mdadm_arrays).value.should be_nil
+      end
+    end
+
+    context 'with 1 configured arrays' do
+      it 'it should find 1 arrays' do
+        Facter.fact(:mdadm).stubs(:value).returns('/sbin/mdadm')
+        Facter::Util::Resolution.stubs(:exec).
+          with('/sbin/mdadm --detail --scan').
+          returns(<<-EOS)
+ARRAY /dev/md0 level=raid0 num-devices=3 metadata=0.90 UUID=cb1e8086:6eb7c4e7:f52f8e1e:d6fa8eb0
+          EOS
+
+        Facter.fact(:mdadm_arrays).value.should == '/dev/md0'
+      end
+
+      it 'it should find 1 arrays' do
+        Facter.fact(:mdadm).stubs(:value).returns('/sbin/mdadm')
+        Facter::Util::Resolution.stubs(:exec).
+          with('/sbin/mdadm --detail --scan').
+          returns(<<-EOS)
+ARRAY /dev/md/leo:0 metadata=1.2 name=leo:0 UUID=72b559cc:ba31aa68:c6f50cd8:a7911136
+          EOS
+
+        Facter.fact(:mdadm_arrays).value.should == '/dev/md/leo:0'
+      end
+    end
+
+    context 'with 2 configured arrays' do
+      it 'it should find 2 arrays' do
+        Facter.fact(:mdadm).stubs(:value).returns('/sbin/mdadm')
+        Facter::Util::Resolution.stubs(:exec).
+          with('/sbin/mdadm --detail --scan').
+          returns(<<-EOS)
+ARRAY /dev/md1 metadata=1.1 name=foo.example.com:1 UUID=cad4da8b:418b3a4b:d27bad88:bb505b62
+ARRAY /dev/md0 metadata=1.0 name=foo.example.com:0 UUID=1b72731b:92ffd70c:17a0e77a:1551624a
+          EOS
+
+        Facter.fact(:mdadm_arrays).value.should == '/dev/md0,/dev/md1'
+      end
+    end
+  end
+
+  context 'mdadm fact not set' do
+    it 'should return nil' do
+      Facter.fact(:mdadm).stubs(:value).returns(nil)
+      Facter.fact(:mdadm_arrays).value.should be_nil
+    end
+  end
+end