provisioning: only update dashboard if hash of json changed

pkg/util/md5.go

@@ -0,0 +1,26 @@
+package util
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"io"
+	"strings"
+)
+
+// Md5Sum calculates the md5sum of a stream
+func Md5Sum(reader io.Reader) (string, error) {
+	var returnMD5String string
+	hash := md5.New()
+	if _, err := io.Copy(hash, reader); err != nil {
+		return returnMD5String, err
+	}
+	hashInBytes := hash.Sum(nil)[:16]
+	returnMD5String = hex.EncodeToString(hashInBytes)
+	return returnMD5String, nil
+}
+
+// Md5Sum calculates the md5sum of a string
+func Md5SumString(input string) (string, error) {
+	buffer := strings.NewReader(input)
+	return Md5Sum(buffer)
+}

pkg/util/md5_test.go

@@ -0,0 +1,17 @@
+package util
+
+import "testing"
+
+func TestMd5Sum(t *testing.T) {
+	input := "dont hash passwords with md5"
+
+	have, err := Md5SumString(input)
+	if err != nil {
+		t.Fatal("expected err to be nil")
+	}
+
+	want := "2d6a56c82d09d374643b926d3417afba"
+	if have != want {
+		t.Fatalf("expected: %s got: %s", want, have)
+	}
+}