Speedup Heroku detection, generalize sys_command

Author: nateberkopec

lib/raven/base.rb

@@ -90,5 +90,13 @@ def safely_prepend(module_name, opts = {})
         opts[:to].send(:include, opts[:from].const_get("Old" + module_name))
       end
     end
+
+    def sys_command(unix_command, win_command = nil)
+      unix_result = `#{unix_command} 2>&1` rescue nil # redirect stderr to stdout
+      return unix_result if unix_result != "" && unix_result
+      return if win_command.nil?
+      win_result = `#{win_command}` rescue nil
+      win_result != "" && win_result
+    end
   end
 end

lib/raven/configuration.rb

@@ -275,15 +275,15 @@ def detect_release
     private
 
     def detect_release_from_heroku
-      sys_dyno_info = `cat /etc/heroku/dyno` rescue nil
-      return unless sys_dyno_info && sys_dyno_info != ""
+      sys_dyno_info = File.read("/etc/heroku/dyno").strip if File.directory?("/etc/heroku") rescue nil
+      return unless sys_dyno_info
 
       # being overly cautious, because if we raise an error Raven won't start
       begin
         hash = JSON.parse(sys_dyno_info)
         hash && hash["release"] && hash["release"]["commit"]
       rescue JSON::JSONError
-        logger.error "Cannot parse Heroku JSON: #{sys_dyno_info}"
+        Raven.logger.error "Cannot parse Heroku JSON: #{sys_dyno_info}"
       end
     end
 

lib/raven/context.rb

@@ -24,10 +24,10 @@ def initialize
     class << self
       def os_context
         @os_context ||= {
-          "name" => sys_command("uname -s") || RbConfig::CONFIG["host_os"],
-          "version" => sys_command("uname -v"),
-          "build" => sys_command("uname -r"),
-          "kernel_version" => sys_command("uname -a", "ver")
+          "name" => Raven.sys_command("uname -s") || RbConfig::CONFIG["host_os"],
+          "version" => Raven.sys_command("uname -v"),
+          "build" => Raven.sys_command("uname -r"),
+          "kernel_version" => Raven.sys_command("uname -a", "ver")
         }
       end
 
@@ -37,13 +37,6 @@ def runtime_context
           "version" => RbConfig::CONFIG["ruby_version"]
         }
       end
-
-      def sys_command(unix_command, win_command = nil)
-        unix_result = `#{unix_command}` rescue nil
-        return unix_result if unix_result != "" && unix_result
-        win_result = `#{win_command}` rescue nil
-        win_result != "" && win_result
-      end
     end
   end
 end