Prefer sha1sum (C) to shasum (Perl).

This should avoid spamming build-log.txt with messages like:

    perl: warning: Setting locale failed.
    perl: warning: Please check that your locale settings:
        LANGUAGE = (unset),
        LC_ALL = (unset),
        LANG = "en_US.UTF-8"
        are supported and installed on your system.
    perl: warning: Falling back to the standard locale ("C").

OSX has shasum but not sha1sum, which is part of GNU coreutils.

build-tools/lib/release.sh

@@ -187,10 +187,10 @@ function kube::release::md5() {
 }
 
 function kube::release::sha1() {
-  if which shasum >/dev/null 2>&1; then
+  if which sha1sum >/dev/null 2>&1; then
-    shasum -a1 "$1" | awk '{ print $1 }'
-  else
     sha1sum "$1" | awk '{ print $1 }'
+  else
+    shasum -a1 "$1" | awk '{ print $1 }'
   fi
 }
 

cluster/common.sh

@@ -817,10 +817,10 @@ EOF
 }
 
 function sha1sum-file() {
-  if which shasum >/dev/null 2>&1; then
+  if which sha1sum >/dev/null 2>&1; then
-    shasum -a1 "$1" | awk '{ print $1 }'
-  else
     sha1sum "$1" | awk '{ print $1 }'
+  else
+    shasum -a1 "$1" | awk '{ print $1 }'
   fi
 }
 

cluster/get-kube-binaries.sh

@@ -104,10 +104,10 @@ function md5sum_file() {
 }
 
 function sha1sum_file() {
-  if which shasum >/dev/null 2>&1; then
+  if which sha1sum >/dev/null 2>&1; then
-    shasum -a1 "$1" | awk '{ print $1 }'
-  else
     sha1sum "$1" | awk '{ print $1 }'
+  else
+    shasum -a1 "$1" | awk '{ print $1 }'
   fi
 }