feat(sdk): add json lib to lua script

go.mod

@@ -154,6 +154,7 @@ require (
 	k8s.io/apimachinery v0.0.0-20190223094358-dcb391cde5ca
 	k8s.io/client-go v10.0.0+incompatible
 	k8s.io/klog v0.2.0 // indirect
+	layeh.com/gopher-json v0.0.0-20201124131017-552bb3c4c3bf
 	sigs.k8s.io/yaml v1.1.0 // indirect
 )
 

go.sum

@@ -834,6 +834,8 @@ k8s.io/client-go v10.0.0+incompatible h1:F1IqCqw7oMBzDkqlcBymRq1450wD0eNqLE9jzUr
 k8s.io/client-go v10.0.0+incompatible/go.mod h1:7vJpHMYJwNQCWgzmNV+VYUl1zCObLyodBc8nIyt8L5s=
 k8s.io/klog v0.2.0 h1:0ElL0OHzF3N+OhoJTL0uca20SxtYt4X4+bzHeqrB83c=
 k8s.io/klog v0.2.0/go.mod h1:Gq+BEi5rUBO/HRz0bTSXDUcqjScdoY3a9IHpCEIOOfk=
+layeh.com/gopher-json v0.0.0-20201124131017-552bb3c4c3bf h1:rRz0YsF7VXj9fXRF6yQgFI7DzST+hsI3TeFSGupntu0=
+layeh.com/gopher-json v0.0.0-20201124131017-552bb3c4c3bf/go.mod h1:ivKkcY8Zxw5ba0jldhZCYYQfGdb2K6u9tbYK1AwMIBc=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 sigs.k8s.io/yaml v1.1.0 h1:4A07+ZFc2wgJwo8YNlQpr1rVlgUDlxXHhPJciaPY5gs=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=

sdk/luascript/luascript.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/yuin/gluare"
 	lua "github.com/yuin/gopher-lua"
+	luajson "layeh.com/gopher-json"
 )
 
 // Check is a type which helps to call a lua script with variables to check something.
@@ -52,6 +53,7 @@ func NewCheck() (*Check, error) {
 
 	//Open gluare module
 	state.PreloadModule("re", gluare.Loader)
+	state.PreloadModule("json", luajson.Loader)
 
 	// Sandboxing lua engine
 	if err := state.DoString("coroutine=nil;debug=nil;io=nil;open=nil;os.rename=nil;os.remove=nil;os.exit=nil;os.clock=nil;os.execute=nil;os.getenv=nil;os.setlocale=nil;os.tmpname=nil"); err != nil {

sdk/luascript/luascript_test.go

@@ -105,6 +105,45 @@ func TestLuaCheckRegularExpression(t *testing.T) {
 	assert.False(t, l.Result)
 }
 
+func TestLuaCheckJSON(t *testing.T) {
+	l, err := NewCheck()
+	require.NoError(t, err)
+	l.SetVariables(map[string]string{
+		"cds.payload": "{\"key1\":\"value1\",\"key2\":2,\"key3\":true}",
+	})
+	require.NoError(t, l.Perform(`
+		local json = require("json")
+    local jsonObj = json.decode(cds_payload)
+		return jsonObj.key1 == "value1"
+	`))
+	assert.False(t, l.IsError)
+	assert.True(t, l.Result)
+
+	require.NoError(t, l.Perform(`
+    local json = require("json")
+    local jsonObj = json.decode(cds_payload)
+    return jsonObj.key1 ~= "value1"
+  `))
+	assert.False(t, l.IsError)
+	assert.False(t, l.Result)
+
+	require.NoError(t, l.Perform(`
+    local json = require("json")
+    local jsonObj = json.decode(cds_payload)
+    return jsonObj.key2 <= 2
+  `))
+	assert.False(t, l.IsError)
+	assert.True(t, l.Result)
+
+	require.NoError(t, l.Perform(`
+    local json = require("json")
+    local jsonObj = json.decode(cds_payload)
+    return jsonObj.key3
+  `))
+	assert.False(t, l.IsError)
+	assert.True(t, l.Result)
+}
+
 func Test_luaPerformStrictCheckOnVariable(t *testing.T) {
 	luaCheck, err := NewCheck()
 	require.NoError(t, err)