Reorganize logging

- Move the opening/closing of logs to the log package
- Use conditional compilation for redirecting stdout/err to logfile,
  Unix allows a superior method to Windows
- Panic output will now to go log file on Unix platforms

log/stdout_unix.go

@@ -0,0 +1,31 @@
+// +build !windows
+
+package log
+
+import (
+	"golang.org/x/sys/unix"
+	"os"
+)
+
+// closeStdin will close stdin on Unix platforms - this is standard practice
+// for daemons
+func closeStdin() {
+	if err := os.Stdin.Close(); err != nil {
+		// Not a fatal error
+		Errorf("Failed to close os.Stdin during log setup")
+	}
+}
+
+// reassignStdout points stdout/stderr to our logfile on systems that support
+// the Dup2 syscall per https://github.com/golang/go/issues/325
+func reassignStdout() {
+	Tracef("Unix reassignStdout()")
+	if err := unix.Dup2(int(logf.Fd()), 1); err != nil {
+		// Not considered fatal
+		Errorf("Failed to re-assign stdout to logfile: %v", err)
+	}
+	if err := unix.Dup2(int(logf.Fd()), 2); err != nil {
+		// Not considered fatal
+		Errorf("Failed to re-assign stderr to logfile: %v", err)
+	}
+}