Also report free disk space in metric description

Now that we take free space into account, adding it to the message make
sense.

lib/riemann/tools/health.rb

@@ -11,6 +11,8 @@ class Health
       include Riemann::Tools
       include Riemann::Tools::Utils
 
+      SI_UNITS = '_kMGTPEZYRQ'
+
       opt :cpu_warning, 'CPU warning threshold (fraction of total jiffies)', default: 0.9
       opt :cpu_critical, 'CPU critical threshold (fraction of total jiffies)', default: 0.95
       opt :disk_warning, 'Disk warning threshold (fraction of space used)', default: 0.9
@@ -404,7 +406,7 @@ def disk
           elsif x > @limits[:disk][:warning] && available < @limits[:disk][:warning_leniency_kb]
             alert "disk #{f[5]}", :warning, x, "#{f[4]} used"
           else
-            alert "disk #{f[5]}", :ok, x, "#{f[4]} used"
+            alert "disk #{f[5]}", :ok, x, "#{f[4]} used, #{number_to_human_size(available * 1024, :floor)} free"
           end
         end
       end
@@ -484,10 +486,17 @@ def human_size_to_number(value)
         when /^\d+R$/i then value.to_i * (1024**9)
         when /^\d+Q$/i then value.to_i * (1024**10)
         else
-          raise %(Malformed size "#{value}", syntax is [0-9]+[kMGTPEZYRQ]?)
+          raise %(Malformed size "#{value}", syntax is [0-9]+[#{SI_UNITS[1..]}]?)
         end
       end
 
+      def number_to_human_size(value, rounding = :round)
+        return value.to_s if value < 1024
+
+        r = Math.log(value, 1024).floor
+        format('%<size>.1f%<unit>ciB', size: (value.to_f / (1024**r)).send(rounding, 1), unit: SI_UNITS[r])
+      end
+
       def tick
         invalidate_cache
 

spec/riemann/tools/health_spec.rb

@@ -20,6 +20,42 @@
     end
   end
 
+  describe('#number_to_human_size') do
+    subject { described_class.new.number_to_human_size(input, rounding) }
+
+    {
+      0                 => %w[0 0 0],
+      1024              => ['1.0kiB', '1.0kiB', '1.0kiB'],
+      2047              => ['1.9kiB', '2.0kiB', '2.0kiB'],
+      2048              => ['2.0kiB', '2.0kiB', '2.0kiB'],
+      2049              => ['2.0kiB', '2.0kiB', '2.1kiB'],
+      44_040_192        => ['42.0MiB', '42.0MiB', '42.0MiB'],
+      1_155_301_638_144 => ['1.0TiB', '1.1TiB', '1.1TiB'],
+    }.each do |input, expected_output|
+      context %(when passed #{input.inspect}) do
+        let(:input) { input }
+
+        context 'when rounding lower' do
+          let(:rounding) { :floor }
+
+          it { is_expected.to eq(expected_output[0]) }
+        end
+
+        context 'when rounding to nearest' do
+          let(:rounding) { :round }
+
+          it { is_expected.to eq(expected_output[1]) }
+        end
+
+        context 'when rounding above' do
+          let(:rounding) { :ceil }
+
+          it { is_expected.to eq(expected_output[2]) }
+        end
+      end
+    end
+  end
+
   describe('#disks') do
     before do
       allow(subject).to receive(:df).and_return(<<~OUTPUT)
@@ -39,29 +75,29 @@
     end
 
     it 'reports all zfs filesystems' do
-      allow(subject).to receive(:alert).with('disk /', :ok, 0.07185344331519083, '7% used')
-      allow(subject).to receive(:alert).with('disk /var/audit', :ok, 2.9484841782529697e-07, '0% used')
-      allow(subject).to receive(:alert).with('disk /var/mail', :ok, 4.529924689197913e-06, '0% used')
-      allow(subject).to receive(:alert).with('disk /tmp', :ok, 0.0001386131897766662, '0% used')
-      allow(subject).to receive(:alert).with('disk /zroot', :ok, 2.9484841782529697e-07, '0% used')
-      allow(subject).to receive(:alert).with('disk /var/crash', :ok, 2.9484841782529697e-07, '0% used')
-      allow(subject).to receive(:alert).with('disk /usr/src', :ok, 2.9484841782529697e-07, '0% used')
-      allow(subject).to receive(:alert).with('disk /usr/home', :ok, 0.33075683535672684, '33% used')
-      allow(subject).to receive(:alert).with('disk /var/tmp', :ok, 4.02065981198671e-07, '0% used')
-      allow(subject).to receive(:alert).with('disk /var/log', :ok, 2.0545157787749945e-05, '0% used')
-      allow(subject).to receive(:alert).with('disk /usr/home/romain/Medias', :ok, 0.39906518922242257, '40% used')
+      allow(subject).to receive(:alert).with('disk /', :ok, 0.07185344331519083, '7% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /var/audit', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /var/mail', :ok, 4.529924689197913e-06, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /tmp', :ok, 0.0001386131897766662, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /zroot', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /var/crash', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /usr/src', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /usr/home', :ok, 0.33075683535672684, '33% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /var/tmp', :ok, 4.02065981198671e-07, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /var/log', :ok, 2.0545157787749945e-05, '0% used, 284.6GiB free')
+      allow(subject).to receive(:alert).with('disk /usr/home/romain/Medias', :ok, 0.39906518922242257, '40% used, 2.0TiB free')
       subject.disk
-      expect(subject).to have_received(:alert).with('disk /', :ok, 0.07185344331519083, '7% used')
-      expect(subject).to have_received(:alert).with('disk /var/audit', :ok, 2.9484841782529697e-07, '0% used')
-      expect(subject).to have_received(:alert).with('disk /var/mail', :ok, 4.529924689197913e-06, '0% used')
-      expect(subject).to have_received(:alert).with('disk /tmp', :ok, 0.0001386131897766662, '0% used')
-      expect(subject).to have_received(:alert).with('disk /zroot', :ok, 2.9484841782529697e-07, '0% used')
-      expect(subject).to have_received(:alert).with('disk /var/crash', :ok, 2.9484841782529697e-07, '0% used')
-      expect(subject).to have_received(:alert).with('disk /usr/src', :ok, 2.9484841782529697e-07, '0% used')
-      expect(subject).to have_received(:alert).with('disk /usr/home', :ok, 0.33075683535672684, '33% used')
-      expect(subject).to have_received(:alert).with('disk /var/tmp', :ok, 4.02065981198671e-07, '0% used')
-      expect(subject).to have_received(:alert).with('disk /var/log', :ok, 2.0545157787749945e-05, '0% used')
-      expect(subject).to have_received(:alert).with('disk /usr/home/romain/Medias', :ok, 0.39906518922242257, '40% used')
+      expect(subject).to have_received(:alert).with('disk /', :ok, 0.07185344331519083, '7% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /var/audit', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /var/mail', :ok, 4.529924689197913e-06, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /tmp', :ok, 0.0001386131897766662, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /zroot', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /var/crash', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /usr/src', :ok, 2.9484841782529697e-07, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /usr/home', :ok, 0.33075683535672684, '33% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /var/tmp', :ok, 4.02065981198671e-07, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /var/log', :ok, 2.0545157787749945e-05, '0% used, 284.6GiB free')
+      expect(subject).to have_received(:alert).with('disk /usr/home/romain/Medias', :ok, 0.39906518922242257, '40% used, 2.0TiB free')
     end
 
     context 'with a foreign locale' do
@@ -74,11 +110,11 @@
       end
 
       it 'reports all zfs filesystems' do
-        allow(subject).to receive(:alert).with('disk /', :ok, 0.6267130394624543, '63% used')
-        allow(subject).to receive(:alert).with('disk /home', :ok, 0.22016432923987797, '23% used')
+        allow(subject).to receive(:alert).with('disk /', :ok, 0.6267130394624543, '63% used, 6.7GiB free')
+        allow(subject).to receive(:alert).with('disk /home', :ok, 0.22016432923987797, '23% used, 66.7GiB free')
         subject.disk
-        expect(subject).to have_received(:alert).with('disk /', :ok, 0.6267130394624543, '63% used')
-        expect(subject).to have_received(:alert).with('disk /home', :ok, 0.22016432923987797, '23% used')
+        expect(subject).to have_received(:alert).with('disk /', :ok, 0.6267130394624543, '63% used, 6.7GiB free')
+        expect(subject).to have_received(:alert).with('disk /home', :ok, 0.22016432923987797, '23% used, 66.7GiB free')
       end
     end
 
@@ -91,9 +127,9 @@
       end
 
       it 'reports a correct lenient state' do
-        allow(subject).to receive(:alert).with('disk /tank', :ok, 0.9002625247490722, '91% used')
+        allow(subject).to receive(:alert).with('disk /tank', :ok, 0.9002625247490722, '91% used, 1.0TiB free')
         subject.disk
-        expect(subject).to have_received(:alert).with('disk /tank', :ok, 0.9002625247490722, '91% used')
+        expect(subject).to have_received(:alert).with('disk /tank', :ok, 0.9002625247490722, '91% used, 1.0TiB free')
       end
     end
   end