Add a chart test framework.

Essentially, the idea is that we have a directory which contains
a set of values files: test/charts/*.in.  Corresponding to each chart
is the fully expanded chart that they generate.  This is stored in
the same directory with the .in replaced with a .expect.  They are
both checked into git.

We then provide a script called test-charts which uses "helm template"
to expand our charts using each values file and makes sure that it
matches the expected chart.  The script will error out if there are
any differences.  It will also emit the diffs.

If the diffs are acceptable, just:

	:; ./bin/test-charts -r <values_file_name>

will put the new expected chart output in place where you can add
it to your commit.

bin/helm-compare-versions

@@ -1,5 +1,12 @@
 #!/bin/sh -e
 
+copy_vals() {
+
+	NEWLOC="$(mktemp "$MYDIR/valuesXXXXXX")"
+	cp $1 $NEWLOC
+	echo $NEWLOC
+}
+
 usage() {
 
 	(  echo "$1"
@@ -19,6 +26,8 @@ I_STASHED_IT=0
 DIFF="diff -u"
 DIFF_ARGS=
 
+MYDIR="$(mktemp -d /tmp/helm-compare-versions-XXXXXX)"
+
 while getopts SU:Yb:n:w f; do
 	case $f in
 	S)	COMPARE_STASHED=1;;
@@ -47,6 +56,9 @@ if [ -z "$NEW_VALUES" ]; then
 	NEW_VALUES="$OLD_VALUES"
 fi
 
+[ ! -f "$NEW_VALUES" ] && NEW_VALUES="$(copy_vals test/charts/$NEW_VALUES.in)"
+[ ! -f "$OLD_VALUES" ] && OLD_VALUES="$(copy_vals test/charts/$OLD_VALUES.in)"
+
 CHART1=
 CHART2=
 CUR_BRANCH=
@@ -61,8 +73,9 @@ cleanup() {
 
 	trap '' PIPE INT
 
-	[ -f "$CHART1" ] && rm "$CHART1"
-	[ -f "$CHART2" ] && rm "$CHART2"
+	if [ -d "$MYDIR" ]; then
+		rm -rf "$MYDIR"
+	fi
 	if [ ! -z "$CUR_BRANCH" ]; then
 		git checkout "$CUR_BRANCH"
 	fi
@@ -86,7 +99,7 @@ if [ ! -z "$NEW_BRANCH" ]; then
 	git checkout "$NEW_BRANCH"
 fi
 
-CHART1=$(mktemp /tmp/chartXXXXXX)
+CHART1="$MYDIR/chart1"
 helm template charts/tezos/ --values "$NEW_VALUES" --namespace tez > "$CHART1"
 
 if [ "$COMPARE_STASHED" = 1 ]; then
@@ -96,7 +109,7 @@ if [ "$COMPARE_STASHED" = 1 ]; then
 	fi
 fi
 
-CHART2=$(mktemp /tmp/chartXXXXXX)
+CHART2="$MYDIR/chart2"
 if [ ! -z "$OLD_BRANCH" ]; then
 	if [ -z "$CUR_BRANCH" ]; then
 		CUR_BRANCH=$(get_branch)

bin/test-charts

@@ -0,0 +1,109 @@
+#!/bin/sh -e
+
+#
+# test-charts runs "helm template" with a list of values files which
+# are found in test/charts/*.in.  Corresponding to each file, there is
+# a file called test/charts/*.expect.  This is the expected output of
+# the template expansion.
+#
+# Running test-charts with no arguments will run all of the tests stopping
+# on the first failure at which point it will emit a unified diff of the
+# changes and exit nonzero.
+#
+# The -l flag will list all of the tests (without the .in suffix)
+#
+# The -r flag will regenerate the expect file corresponding to one or
+# more of the tests.  These must be provided as arguments on the command
+# line and said arguments do not include the  .in suffix.
+
+OUT=
+
+cleanup() {
+	rm -f $OUT
+}
+trap cleanup EXIT INT PIPE
+
+run_test() {
+	IN="$1"
+	OUT="$(mktemp /tmp/chartXXXXXX)"
+	EXPECT="${1%.in}.expect"
+
+	echo "Testing $IN"
+
+	helm template --values "$IN" -n testing charts/tezos > $OUT
+
+	if ! cmp "$EXPECT" "$OUT"; then
+		echo "Test chart $IN failed"
+		echo
+		echo "Here are the differences from what we expect"
+		echo "What we expect will be -, what got +"
+		$DIFF "$EXPECT" "$OUT"
+		exit 1
+	fi
+}
+
+run_tests() {
+	for i in test/charts/*.in; do
+		run_test $i
+	done
+}
+
+list_tests() {
+	ls test/charts/*.in | sed 's,^test/charts/\(.*\).in,\1,'
+}
+
+regen() {
+	for i; do
+		IN="test/charts/$i.in"
+		if ! [ -f "$IN" ]; then
+			echo Test $i doesn\'t exist.
+			exit 1
+		fi
+		echo "Regenerating $IN"
+		EXPECT="${IN%.in}.expect"
+		helm template --values "$IN" -n testing charts/tezos > $EXPECT
+	done
+}
+
+usage() {
+	echo "$@" 1>&2
+	echo "Usage: $0 [-l]"
+	echo "       $0 -r test_name [test_name ...]"
+	echo
+	echo "    -l lists the tests"
+	echo "    -r will cause the expected YAML files to be rebuilt for"
+	echo "       the named tests"
+	exit 1
+}
+
+#
+# First, get to the top level and ensure that we're tezos-k8s to
+# some degree.
+
+GIT_BASE="$(git rev-parse --show-toplevel)"
+if [ -z "$GIT_BASE" -o ! -d "$GIT_BASE/charts/tezos" ]; then
+	usage "Not in a tezos-k8s git repo, failing"
+fi
+cd "$GIT_BASE"
+
+#
+# And now for main:
+
+DIFF="diff -u"
+JOB=run_tests
+
+while getopts Ylr f; do
+	case $f in
+	Y)	DIFF="dyff between";;
+	l)	JOB=list;;
+	r)	JOB=regen;;
+	\?)	usage "Invalid option $f";;
+	esac
+done
+shift $(expr $OPTIND - 1)
+
+case "$JOB" in
+	list)		list_tests;;
+	run_tests)	run_tests;;
+	regen)		regen "$@";;
+esac