744 fixed error messages

pkg/engine/validation.go

@@ -31,16 +31,25 @@ func Validate(policyContext PolicyContext) (resp response.EngineResponse) {
 		if reflect.DeepEqual(resp, response.EngineResponse{}) {
 			return
 		}
-		startResultResponse(&resp, policy, newR)
-		endResultResponse(logger, &resp, startTime)
+		var resource unstructured.Unstructured
 		if reflect.DeepEqual(resp.PatchedResource, unstructured.Unstructured{}) {
 			// for delete requests patched resource will be oldR since newR is empty
 			if reflect.DeepEqual(newR, unstructured.Unstructured{}) {
-				resp.PatchedResource = oldR
+				resource = oldR
 			} else {
-				resp.PatchedResource = newR
+				resource = newR
 			}
 		}
+		for i := range resp.PolicyResponse.Rules {
+			messageInterface, err := variables.SubstituteVars(logger, ctx, resp.PolicyResponse.Rules[i].Message)
+			if err != nil {
+				continue
+			}
+			resp.PolicyResponse.Rules[i].Message, _ = messageInterface.(string)
+		}
+		resp.PatchedResource = resource
+		startResultResponse(&resp, policy, resource)
+		endResultResponse(logger, &resp, startTime)
 	}()
 
 	// If request is delete, newR will be empty

pkg/engine/variables/vars.go

@@ -11,8 +11,7 @@ import (
 )
 
 const (
-	variableRegex  = `\{\{([^{}]*)\}\}`
-	singleVarRegex = `^\{\{([^{}]*)\}\}$`
+	variableRegex = `\{\{([^{}]*)\}\}`
 )
 
 //SubstituteVars replaces the variables with the values defined in the context
@@ -42,7 +41,7 @@ func subVars(log logr.Logger, ctx context.EvalInterface, pattern interface{}, pa
 
 		return subArray(log, ctx, sliceCopy, path, errs)
 	case string:
-		return subValR(log, ctx, typedPattern, path, errs)
+		return subValR(ctx, typedPattern, path, errs)
 	default:
 		return pattern
 	}
@@ -68,108 +67,46 @@ func subArray(log logr.Logger, ctx context.EvalInterface, patternList []interfac
 }
 
 // subValR resolves the variables if defined
-func subValR(log logr.Logger, ctx context.EvalInterface, valuePattern string, path string, errs *[]error) interface{} {
+func subValR(ctx context.EvalInterface, valuePattern string, path string, errs *[]error) interface{} {
+	originalPattern := valuePattern
+	var failedVars []interface{}
 
-	// variable values can be scalar values(string,int, float) or they can be obects(map,slice)
-	// - {{variable}}
-	// there is a single variable resolution so the value can be scalar or object
-	// - {{variable1--{{variable2}}}}}
-	// variable2 is evaluted first as an individual variable and can be have scalar or object values
-	// but resolving the outer variable, {{variable--<value>}}
-	// if <value> is scalar then it can replaced, but for object types its tricky
-	// as object cannot be directy replaced, if the object is stringyfied then it loses it structure.
-	// since this might be a potential place for error, required better error reporting and handling
+	defer func() {
+		if len(failedVars) > 0 {
+			*errs = append(*errs, fmt.Errorf("failed to resolve %v at path %s", failedVars, path))
+		}
+	}()
 
-	// object values are only suported for single variable substitution
-	if ok, retVal := processIfSingleVariable(log, ctx, valuePattern, path, errs); ok {
-		return retVal
-	}
-	// var emptyInterface interface{}
-	var failedVars []string
-	// process type string
+	regex := regexp.MustCompile(`\{\{([^{}]*)\}\}`)
 	for {
-		valueStr := valuePattern
-		if len(failedVars) != 0 {
-			log.Info("failed to resolve variablesl short-circuiting")
+		if vars := regex.FindAllString(valuePattern, -1); len(vars) > 0 {
+			for _, variable := range vars {
+				underlyingVariable := strings.ReplaceAll(strings.ReplaceAll(variable, "}}", ""), "{{", "")
+				substitutedVar, err := ctx.Query(underlyingVariable)
+				if err != nil {
+					failedVars = append(failedVars, underlyingVariable)
+					return nil
+				}
+				if val, ok := substitutedVar.(string); ok {
+					if val == "" {
+						failedVars = append(failedVars, underlyingVariable)
+						return nil
+					}
+					valuePattern = strings.Replace(valuePattern, variable, val, -1)
+				} else {
+					if substitutedVar != nil {
+						if originalPattern == variable {
+							return substitutedVar
+						}
+					}
+					failedVars = append(failedVars, underlyingVariable)
+					return nil
+				}
+			}
+		} else {
 			break
 		}
-		// get variables at this level
-		validRegex := regexp.MustCompile(variableRegex)
-		groups := validRegex.FindAllStringSubmatch(valueStr, -1)
-		if len(groups) == 0 {
-			// there was no match
-			// not variable defined
-			break
-		}
-		subs := map[string]interface{}{}
-		for _, group := range groups {
-			if _, ok := subs[group[0]]; ok {
-				// value has already been substituted
-				continue
-			}
-			// here we do the querying of the variables from the context
-			variable, err := ctx.Query(group[1])
-			if err != nil {
-				// error while evaluating
-				failedVars = append(failedVars, group[1])
-				continue
-			}
-			// path not found in context and value stored in null/nill
-			if variable == nil {
-				failedVars = append(failedVars, group[1])
-				continue
-			}
-			// get values for each and replace
-			subs[group[0]] = variable
-		}
-		// perform substitutions
-		newVal := valueStr
-		for k, v := range subs {
-			// if value is of type string then cast else consider it as direct replacement
-			if val, ok := v.(string); ok {
-				newVal = strings.Replace(newVal, k, val, -1)
-				continue
-			}
-			// if type is not scalar then consider this as a failed variable
-			log.Info("variable resolves to non-scalar value. Non-Scalar values are not supported for nested variables", "variable", k, "value", v)
-			failedVars = append(failedVars, k)
-		}
-		valuePattern = newVal
-	}
-	// update errors if any
-	if len(failedVars) > 0 {
-		*errs = append(*errs, fmt.Errorf("failed to resolve %v at path %s", failedVars, path))
 	}
 
 	return valuePattern
 }
-
-// processIfSingleVariable will process the evaluation of single variables
-// {{variable-{{variable}}}} -> compound/nested variables
-// {{variable}}{{variable}} -> multiple variables
-// {{variable}} -> single variable
-// if the value can be evaluted return the value
-// -> return value can be scalar or object type
-// -> if the variable is not present in the context then add an error and dont process further
-func processIfSingleVariable(log logr.Logger, ctx context.EvalInterface, valuePattern interface{}, path string, errs *[]error) (bool, interface{}) {
-	valueStr, ok := valuePattern.(string)
-	if !ok {
-		log.Info("failed to convert to string", "pattern", valuePattern)
-		return false, nil
-	}
-	// get variables at this level
-	validRegex := regexp.MustCompile(singleVarRegex)
-	groups := validRegex.FindAllStringSubmatch(valueStr, -1)
-	if len(groups) == 0 {
-		return false, nil
-	}
-	// as there will be exactly one variable based on the above regex
-	group := groups[0]
-	variable, err := ctx.Query(group[1])
-	if err != nil || variable == nil {
-		*errs = append(*errs, fmt.Errorf("failed to resolve %v at path %s", group[1], path))
-		// return the same value pattern, and add un-resolvable variable error
-		return true, valuePattern
-	}
-	return true, variable
-}

pkg/engine/variables/vars_test.go

@@ -153,5 +153,5 @@ func Test_SubvarRecursive(t *testing.T) {
 	ctx := context.NewContext()
 	assert.Assert(t, ctx.AddResource(resourceRaw))
 	errs := []error{}
-	subValR(log.Log, ctx, string(patternRaw), "/", &errs)
+	subValR(ctx, string(patternRaw), "/", &errs)
 }