add error handling

Signed-off-by: Jose Asuncion <jeunito@gmail.com>

2 files changed, 59 insertions, 39 deletions

diff --git a/lib/ohai/plugins/linux/filesystem.rb b/lib/ohai/plugins/linux/filesystem.rb
index 4e8fd0de..27d407a9 100644
--- a/lib/ohai/plugins/linux/filesystem.rb
+++ b/lib/ohai/plugins/linux/filesystem.rb
@@ -95,52 +95,60 @@ Ohai.plugin(:Filesystem) do
     fs = Mash.new
 
     # Grab filesystem data from df
-    so = shell_out("df -P")
-    so.stdout.each_line do |line|
-      case line
-      when /^Filesystem\s+1024-blocks/
-        next
-      when /^(.+?)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+\%)\s+(.+)$/
-        key = "#{$1},#{$6}"
-        fs[key] = Mash.new
-        fs[key][:device] = $1
-        fs[key][:kb_size] = $2
-        fs[key][:kb_used] = $3
-        fs[key][:kb_available] = $4
-        fs[key][:percent_used] = $5
-        fs[key][:mount] = $6
+    if which("df")
+      so = shell_out("df -P")
+      so.stdout.each_line do |line|
+        case line
+        when /^Filesystem\s+1024-blocks/
+          next
+        when /^(.+?)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+\%)\s+(.+)$/
+          key = "#{$1},#{$6}"
+          fs[key] = Mash.new
+          fs[key][:device] = $1
+          fs[key][:kb_size] = $2
+          fs[key][:kb_used] = $3
+          fs[key][:kb_available] = $4
+          fs[key][:percent_used] = $5
+          fs[key][:mount] = $6
+        end
       end
-    end
 
-    # Grab filesystem inode data from df
-    so = shell_out("df -iP")
-    so.stdout.each_line do |line|
-      case line
-      when /^Filesystem\s+Inodes/
-        next
-      when /^(.+?)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+\%)\s+(.+)$/
-        key = "#{$1},#{$6}"
-        fs[key] ||= Mash.new
-        fs[key][:device] = $1
-        fs[key][:total_inodes] = $2
-        fs[key][:inodes_used] = $3
-        fs[key][:inodes_available] = $4
-        fs[key][:inodes_percent_used] = $5
-        fs[key][:mount] = $6
+      # Grab filesystem inode data from df
+      so = shell_out("df -iP")
+      so.stdout.each_line do |line|
+        case line
+        when /^Filesystem\s+Inodes/
+          next
+        when /^(.+?)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+\%)\s+(.+)$/
+          key = "#{$1},#{$6}"
+          fs[key] ||= Mash.new
+          fs[key][:device] = $1
+          fs[key][:total_inodes] = $2
+          fs[key][:inodes_used] = $3
+          fs[key][:inodes_available] = $4
+          fs[key][:inodes_percent_used] = $5
+          fs[key][:mount] = $6
+        end
       end
+    else
+      Ohai::Log.warn("df is not available")
     end
 
     # Grab mount information from /bin/mount
-    so = shell_out("mount")
-    so.stdout.each_line do |line|
-      if line =~ /^(.+?) on (.+?) type (.+?) \((.+?)\)$/
-        key = "#{$1},#{$2}"
-        fs[key] = Mash.new unless fs.has_key?(key)
-        fs[key][:device] = $1
-        fs[key][:mount] = $2
-        fs[key][:fs_type] = $3
-        fs[key][:mount_options] = $4.split(",")
+    if which("mount")
+      so = shell_out("mount")
+      so.stdout.each_line do |line|
+        if line =~ /^(.+?) on (.+?) type (.+?) \((.+?)\)$/
+          key = "#{$1},#{$2}"
+          fs[key] = Mash.new unless fs.has_key?(key)
+          fs[key][:device] = $1
+          fs[key][:mount] = $2
+          fs[key][:fs_type] = $3
+          fs[key][:mount_options] = $4.split(",")
+        end
       end
+    else
+      Ohai::Log.warn("mount is not available")
     end
 
     # We used to try to decide if we wanted to run lsblk or blkid
diff --git a/spec/unit/plugins/linux/filesystem_spec.rb b/spec/unit/plugins/linux/filesystem_spec.rb
index 96382b1e..72aa8f02 100644
--- a/spec/unit/plugins/linux/filesystem_spec.rb
+++ b/spec/unit/plugins/linux/filesystem_spec.rb
@@ -27,6 +27,8 @@ describe Ohai::System, "Linux filesystem plugin" do
     allow(plugin).to receive(:shell_out).with("df -iP").and_return(mock_shell_out(0, "", ""))
     allow(plugin).to receive(:shell_out).with("mount").and_return(mock_shell_out(0, "", ""))
     allow(plugin).to receive(:which).with("lsblk").and_return(nil)
+    allow(plugin).to receive(:which).with("df").and_return("/bin/df")
+    allow(plugin).to receive(:which).with("mount").and_return("/bin/mount")
     allow(plugin).to receive(:which).with("blkid").and_return("/sbin/blkid")
     allow(plugin).to receive(:shell_out).with("/sbin/blkid", timeout: 60).and_return(mock_shell_out(0, "", ""))
 
@@ -529,4 +531,14 @@ BLKID_TYPE
       expect(plugin[:filesystem]["by_mountpoint"]["/mnt"][:devices]).to eq(["/dev/sdb1", "/dev/sdc1"])
     end
   end
+
+  %w{df mount}.each do |command|
+    describe "when #{command} does not exist" do
+      it "logs event" do
+        allow(plugin).to receive(:which).with(command).and_return(nil)
+        expect(Ohai::Log).to receive(:warn).with("#{command} is not available")
+        plugin.run
+      end
+    end
+  end
 end