CloudWatch: Handle permissions error and update docs (#88524)

docs/sources/datasources/aws-cloudwatch/_index.md

@@ -123,6 +123,12 @@ You can attach these permissions to the IAM role or IAM user you configured in [
       "Effect": "Allow",
       "Action": "tag:GetResources",
       "Resource": "*"
+    },
+    {
+      "Sid": "AllowReadingResourceMetricsFromPerformanceInsights",
+      "Effect": "Allow",
+      "Action": "pi:GetResourceMetrics",
+      "Resource": "*"
     }
   ]
 }
@@ -182,6 +188,12 @@ You can attach these permissions to the IAM role or IAM user you configured in [
       ],
       "Resource": "*"
     },
+    {
+      "Sid": "AllowReadingResourceMetricsFromPerformanceInsights",
+      "Effect": "Allow",
+      "Action": "pi:GetResourceMetrics",
+      "Resource": "*"
+    },
     {
       "Sid": "AllowReadingLogsFromCloudWatch",
       "Effect": "Allow",

pkg/tsdb/cloudwatch/models/query_row_response.go

@@ -1,6 +1,8 @@
 package models
 
-import "github.com/aws/aws-sdk-go/service/cloudwatch"
+import (
+	"github.com/aws/aws-sdk-go/service/cloudwatch"
+)
 
 // queryRowResponse represents the GetMetricData response for a query row in the query editor.
 type QueryRowResponse struct {
@@ -8,6 +10,8 @@ type QueryRowResponse struct {
 	ErrorCodes             map[string]bool
 	HasArithmeticError     bool
 	ArithmeticErrorMessage string
+	HasPermissionError     bool
+	PermissionErrorMessage string
 	Metrics                []*cloudwatch.MetricDataResult
 	StatusCode             string
 }
@@ -23,6 +27,10 @@ func NewQueryRowResponse(errors map[string]bool) QueryRowResponse {
 }
 
 func (q *QueryRowResponse) AddMetricDataResult(mdr *cloudwatch.MetricDataResult) {
+	if mdr.Label == nil {
+		return
+	}
+
 	if partialData, ok := q.partialDataSet[*mdr.Label]; ok {
 		partialData.Timestamps = append(partialData.Timestamps, mdr.Timestamps...)
 		partialData.Values = append(partialData.Values, mdr.Values...)
@@ -44,3 +52,8 @@ func (q *QueryRowResponse) AddArithmeticError(message *string) {
 	q.HasArithmeticError = true
 	q.ArithmeticErrorMessage = *message
 }
+
+func (q *QueryRowResponse) AddPermissionError(message *string) {
+	q.HasPermissionError = true
+	q.PermissionErrorMessage = *message
+}

pkg/tsdb/cloudwatch/response_parser.go

@@ -35,6 +35,10 @@ func (e *cloudWatchExecutor) parseResponse(ctx context.Context, startTime time.T
 			dataRes.Error = fmt.Errorf("ArithmeticError in query %q: %s", queryRow.RefId, response.ArithmeticErrorMessage)
 		}
 
+		if response.HasPermissionError {
+			dataRes.Error = fmt.Errorf("PermissionError in query %q: %s", queryRow.RefId, response.PermissionErrorMessage)
+		}
+
 		var err error
 		dataRes.Frames, err = buildDataFrames(ctx, startTime, endTime, response, queryRow)
 		if err != nil {
@@ -79,6 +83,9 @@ func aggregateResponse(getMetricDataOutputs []*cloudwatch.GetMetricDataOutput) m
 				if *message.Code == "ArithmeticError" {
 					response.AddArithmeticError(message.Value)
 				}
+				if *message.Code == "Forbidden" {
+					response.AddPermissionError(message.Value)
+				}
 			}
 
 			response.AddMetricDataResult(r)

pkg/tsdb/cloudwatch/response_parser_test.go

@@ -135,6 +135,15 @@ func TestCloudWatchResponseParser(t *testing.T) {
 			})
 		})
 	})
+
+	t.Run("when receiving a permissions error should pass it to the user", func(t *testing.T) {
+		getMetricDataOutputs, err := loadGetMetricDataOutputsFromFile("./testdata/permissions-error-output.json")
+		require.NoError(t, err)
+		aggregatedResponse := aggregateResponse(getMetricDataOutputs)
+
+		assert.True(t, aggregatedResponse["a"].HasPermissionError)
+		assert.Equal(t, "Access denied when getting data - please check that you have the pi:GetResourceMetrics permission", aggregatedResponse["a"].PermissionErrorMessage)
+	})
 }
 
 func Test_buildDataFrames_parse_label_to_name_and_labels(t *testing.T) {

pkg/tsdb/cloudwatch/testdata/permissions-error-output.json

@@ -0,0 +1,16 @@
+[
+  {
+    "Messages": null,
+    "MetricDataResults": [
+      {
+        "Id": "a",
+        "Messages": [{
+          "Code": "Forbidden",
+          "Value": "Access denied when getting data - please check that you have the pi:GetResourceMetrics permission"
+        }],
+        "StatusCode": "Forbidden"
+      }
+    ],
+    "NextToken": null
+  }
+]