[mdadm] Handle journal and spare devices properly (#1094)

Journal and spare devices are important to report clearly. This puts
them in their own arrays.

I'd like to backport this to 12.x - but it's unclear here what
backwards compat here is.

I *could* put *all* devices into `members` and then also specify special
members in their own list... but prior to me fixing this plugin a few
months, ago, spares and journal wouldn't have been reported anyway...
and it is probably incorrect to report them as normal members... so this
feels like a further fix on a previous fix, so I've opted for just
fixing it. However, let me know how you guys feel.

Signed-off-by: Phil Dibowitz <phil@ipom.com>

2 files changed, 54 insertions, 6 deletions

diff --git a/lib/ohai/plugins/linux/mdadm.rb b/lib/ohai/plugins/linux/mdadm.rb
index bd4d780b..407e1dd9 100644
--- a/lib/ohai/plugins/linux/mdadm.rb
+++ b/lib/ohai/plugins/linux/mdadm.rb
@@ -64,10 +64,35 @@ Ohai.plugin(:Mdadm) do
           # unless the array is inactive, in which case you don't get a raid
           # level.
           members = pieces.drop_while { |x| !x.start_with?("raid", "inactive") }
-          # drop the 'raid' too
-
+          # and drop that too
           members.shift unless members.empty?
-          devices[device] = members.map { |s| s.match(/(.+)\[\d+\]/)[1] }
+          devices[device] = {
+            "active" => [],
+            "spare" => [],
+            "journal" => nil,
+          }
+          members.each do |member|
+            # We want to match the device, and optionally the type
+            # most entries will look like:
+            #   sdc1[5]
+            # but some will look like:
+            #   sdc1[5](J)
+            # where the format is:
+            #   <device>[<number in array>](<type>)
+            # Type can be things like "J" for a journal device, or "S" for
+            # a spare device.
+            m = member.match(/(.+)\[\d+\](?:\((\w)\))?/)
+            member_device = m[1]
+            member_type = m[2]
+            case member_type
+            when "J"
+              devices[device]["journal"] = member_device
+            when "S"
+              devices[device]["spare"] << member_device
+            else
+              devices[device]["active"] << member_device
+            end
+          end
         end
       end
 
@@ -82,7 +107,9 @@ Ohai.plugin(:Mdadm) do
 
           # if the mdadm command was sucessful pass so.stdout to create_raid_device_mash to grab the tidbits we want
           mdadm[device] = create_raid_device_mash(so.stdout) if so.stdout
-          mdadm[device]["members"] = devices[device]
+          mdadm[device]["members"] = devices[device]["active"]
+          mdadm[device]["spares"] = devices[device]["spare"]
+          mdadm[device]["journal"] = devices[device]["journal"]
         end
       end
     end
diff --git a/spec/unit/plugins/linux/mdadm_spec.rb b/spec/unit/plugins/linux/mdadm_spec.rb
index a3feeba1..15e9bf10 100644
--- a/spec/unit/plugins/linux/mdadm_spec.rb
+++ b/spec/unit/plugins/linux/mdadm_spec.rb
@@ -142,8 +142,29 @@ MD
       allow(File).to receive(:open).with("/proc/mdstat").and_return(new_mdstat)
 
       @plugin.run
-      expect(@plugin[:mdadm][:md0][:members].sort).to eq(%w{nvme2n1p3})
+      expect(@plugin[:mdadm][:md0][:spares]).to eq(%w{nvme2n1p3})
+    end
+
+    it "should report journal devices" do
+      new_mdstat = double("/proc/mdstat_journal")
+      allow(new_mdstat).to receive(:each).
+        and_yield("Personalies : [raid6]").
+        and_yield("md0 : active (somecraphere) <morestuff raid6 sdbc1[7] sdd1[6] sde1[5] sdd1[4] sde1[3] sdf1[2] sdg1[1] nvme2n1p3[0](J)")
+      allow(File).to receive(:open).with("/proc/mdstat").and_return(new_mdstat)
+
+      @plugin.run
+      expect(@plugin[:mdadm][:md0][:journal]).to eq("nvme2n1p3")
     end
-  end
 
+    it "should report spare devices" do
+      new_mdstat = double("/proc/mdstat_spare")
+      allow(new_mdstat).to receive(:each).
+        and_yield("Personalies : [raid6]").
+        and_yield("md0 : active (somecraphere) <morestuff raid6 sdbc1[7] sdd1[6] sde1[5] sdd1[4] sde1[3] sdf1[2] sdg1[1] sdh1[0](S)")
+      allow(File).to receive(:open).with("/proc/mdstat").and_return(new_mdstat)
+
+      @plugin.run
+      expect(@plugin[:mdadm][:md0][:spares]).to eq(%w{sdh1})
+    end
+  end
 end