Golang debian postinst for Uber

debian-postinst.diff

diff --git a/debian/golang-X.Y-go.postinst b/debian/golang-X.Y-go.postinst
index 160957243..388aef2d1 100644
--- a/debian/golang-X.Y-go.postinst
+++ b/debian/golang-X.Y-go.postinst
@@ -5,6 +5,20 @@ case "$1" in
 	configure)
 		# Very ugly hack to set timestamps same as /usr/lib/go-X.Y/bin/go
 		find /usr/lib/go-X.Y/pkg -exec touch -r /usr/lib/go-X.Y/bin/go {} \;
+		# Setup alternatives
+		# Priority: base of 100 + go version; 1.4.2 = 100 + 42; 1.5 = 100 + 50
+		go=$(/usr/lib/go-X.Y/bin/go version | awk '{
+			gsub(/^go1|[.]/, "", $3);
+			gsub(/([^0-9.]+.*)$/, "", $3);
+			if ($3 ~ /^[0-9]$/) {
+				$3 = $3 "0";
+			};
+			print $3;
+		}')
+		priority=$(( 100 + $go ))
+		update-alternatives \
+			--install /usr/bin/go go /usr/lib/go-X.Y/bin/go $priority \
+			--slave /usr/bin/gofmt gofmt /usr/lib/go-X.Y/bin/gofmt
 		;;
 	*)
 		;;
diff --git a/debian/golang-X.Y-go.prerm b/debian/golang-X.Y-go.prerm
new file mode 100644
index 000000000..ad946c89e
--- /dev/null
+++ b/debian/golang-X.Y-go.prerm
@@ -0,0 +1,21 @@
+#!/bin/sh
+set -e
+
+case "$1" in
+   remove|deconfigure)
+       update-alternatives --remove go /usr/lib/go-X.Y/bin/go
+       ;;
+
+   upgrade|failed-upgrade)
+       ;;
+
+   *)
+       echo >&2 "prerm called with unknown argument: $1"
+       exit 0
+       ;;
+esac
+
+
+#DEBHELPER#
+
+exit 0