Update readme

README.md

@@ -31,6 +31,6 @@ export ACR_ODOO_OAUTH_CLIENT_ID="your_client_id" # see https://docs.central.vshn
 export ACR_ODOO_OAUTH_CLIENT_SECRET="your_client_secret"
 
 # Run a query
-go run . report --query 'sum by (label) (metric)' --begin "2023-07-08T13:00:00Z" --product-id "your-odoo-product-id" --instance-pattern "instance-%(label)s" --unit-id "your_odoo_unit_id" --timerange 1h --item-desc-pattern "This is a description." --item-group-desc-pattern "Instance %(label)s"
+go run . report --query 'sum by (label) (metric)' --begin "2023-07-08T13:00:00Z" --product-id "your-odoo-product-id" --instance-jsonnet 'local labels = std.extVar("labels"); "instance-%(label)s" % labels' --unit-id "your_odoo_unit_id" --timerange 1h --item-description-jsonnet '"This is a description."' --item-group-description-jsonnet 'local labels = std.extVar("labels"); "Instance %(label)s" % labels'
 
-```
+```

pkg/report/report.go

@@ -132,14 +132,14 @@ func processSample(ctx context.Context, odooClient OdooClient, args ReportArgs,
 	instanceStr := ""
 	err = json.Unmarshal([]byte(instance), &instanceStr)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to interpolate instance template: %w", err)
 	}
 
 	var groupStr string
 	if args.ItemGroupDescriptionJsonnet != "" {
 		group, err := vm.EvaluateAnonymousSnippet("group.json", args.ItemGroupDescriptionJsonnet)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to interpolate group description template: %w", err)
 		}
 		err = json.Unmarshal([]byte(group), &groupStr)
 		if err != nil {
@@ -151,7 +151,7 @@ func processSample(ctx context.Context, odooClient OdooClient, args ReportArgs,
 	if args.ItemDescriptionJsonnet != "" {
 		description, err := vm.EvaluateAnonymousSnippet("description.json", args.ItemDescriptionJsonnet)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to interpolate description template: %w", err)
 		}
 		err = json.Unmarshal([]byte(description), &descriptionStr)
 		if err != nil {