Pull the complete version string of Erlangerlang

Improve the shellout with help of StackOverflow and srenatus. This
requires less fragile work in Ruby by formatting the data in erlang
properly.

Signed-off-by: Tim Smith <tsmith@chef.io>

2 files changed, 8 insertions, 10 deletions

diff --git a/lib/ohai/plugins/erlang.rb b/lib/ohai/plugins/erlang.rb
index 94a7a297..5097b742 100644
--- a/lib/ohai/plugins/erlang.rb
+++ b/lib/ohai/plugins/erlang.rb
@@ -24,13 +24,11 @@ Ohai.plugin(:Erlang) do
     erlang = Mash.new
 
     begin
-      so = shell_out("erl -eval 'erlang:display(erlang:system_info(otp_release)), erlang:display(erlang:system_info(version)), erlang:display(erlang:system_info(nif_version)), halt().'  -noshell")
+      so = shell_out("erl -eval '{ok, Ver} = file:read_file(filename:join([code:root_dir(), \"releases\", erlang:system_info(otp_release), \"OTP_VERSION\"])), Vsn = binary:bin_to_list(Ver, {0, byte_size(Ver) - 1}), io:format(\"~s,~s,~s\", [Vsn, erlang:system_info(version), erlang:system_info(nif_version)]), halt().' -noshell")
       # Sample output:
-      # "18"
-      # "7.3"
-      # "2.10"
+      # 19.1,8.1,2.11
       if so.exitstatus == 0
-        output = so.stdout.split(/\r\n/).map! { |x| x.delete('\\"') }
+        output = so.stdout.split(",")
         erlang[:version] = output[0]
         erlang[:erts_version] = output[1]
         erlang[:nif_version] = output[2]
diff --git a/spec/unit/plugins/erlang_spec.rb b/spec/unit/plugins/erlang_spec.rb
index b7f51f14..968ec033 100644
--- a/spec/unit/plugins/erlang_spec.rb
+++ b/spec/unit/plugins/erlang_spec.rb
@@ -25,10 +25,10 @@ describe Ohai::System, "plugin erlang" do
   before(:each) do
     plugin[:languages] = Mash.new
     erl_v_output = "Erlang (SMP,ASYNC_THREADS,HIPE) (BEAM) emulator version 7.3\n"
-    erl_systeminfo_output = "\"18\"\r\n\"7.3\"\r\n\"2.10\"\r\n"
+    erl_systeminfo_output = "19.1,8.1,2.11"
     allow(plugin).to receive(:shell_out).with("erl +V")
                                         .and_return(mock_shell_out(0, "", erl_v_output))
-    allow(plugin).to receive(:shell_out).with("erl -eval 'erlang:display(erlang:system_info(otp_release)), erlang:display(erlang:system_info(version)), erlang:display(erlang:system_info(nif_version)), halt().'  -noshell")
+    allow(plugin).to receive(:shell_out).with("erl -eval '{ok, Ver} = file:read_file(filename:join([code:root_dir(), \"releases\", erlang:system_info(otp_release), \"OTP_VERSION\"])), Vsn = binary:bin_to_list(Ver, {0, byte_size(Ver) - 1}), io:format(\"~s,~s,~s\", [Vsn, erlang:system_info(version), erlang:system_info(nif_version)]), halt().' -noshell")
                                         .and_return(mock_shell_out(0, erl_systeminfo_output, ""))
   end
 
@@ -44,17 +44,17 @@ describe Ohai::System, "plugin erlang" do
 
   it "sets languages[:erlang][:version]" do
     plugin.run
-    expect(plugin.languages[:erlang][:version]).to eql("18")
+    expect(plugin.languages[:erlang][:version]).to eql("19.1")
   end
 
   it "sets languages[:erlang][:erts_version]" do
     plugin.run
-    expect(plugin.languages[:erlang][:erts_version]).to eql("7.3")
+    expect(plugin.languages[:erlang][:erts_version]).to eql("8.1")
   end
 
   it "sets languages[:erlang][:nif_version]" do
     plugin.run
-    expect(plugin.languages[:erlang][:nif_version]).to eql("2.10")
+    expect(plugin.languages[:erlang][:nif_version]).to eql("2.11")
   end
 
   it "does not set languages[:erlang] if the erl commands fails" do