Add support for filtering expected resource types

Add optional resource-types input parameter that allows specifying which AWS
resource types the stack update is expected to change. The value is passed to
CloudFormation UpdateStack API as ResourceTypes parameter.

Author: artyom

action.yml

@@ -11,6 +11,9 @@ inputs:
       Newline-separated parameters to change in the Name=Value format.
       Stack parameters not set here would retain their existing values.
     required: true
+  resource-types:
+    description: >
+      Optional newline-separated AWS resource types that stack update is expected to change.
 
 runs:
   using: docker

go.mod

@@ -1,15 +1,15 @@
 module github.com/artyom/update-cloudformation-stack
 
-go 1.23.3
+go 1.25.0
 
 require (
+	github.com/aws/aws-sdk-go-v2 v1.32.5
 	github.com/aws/aws-sdk-go-v2/config v1.28.5
 	github.com/aws/aws-sdk-go-v2/service/cloudformation v1.56.0
 	github.com/aws/smithy-go v1.22.1
 )
 
 require (
-	github.com/aws/aws-sdk-go-v2 v1.32.5 // indirect
 	github.com/aws/aws-sdk-go-v2/credentials v1.17.46 // indirect
 	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.20 // indirect
 	github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.24 // indirect

main.go

@@ -52,6 +52,15 @@ func run(ctx context.Context, stackName string, args []string) error {
 		return errors.New("empty parameters list")
 	}
 	debugf("loaded parameters: %v", toReplace)
+	var resourceTypes []string
+	if val := os.Getenv("INPUT_RESOURCE-TYPES"); val != "" {
+		for s := range strings.Lines(val) {
+			if s = strings.TrimSpace(s); s != "" {
+				resourceTypes = append(resourceTypes, s)
+			}
+		}
+	}
+	debugf("resource types: %v", resourceTypes)
 	cfg, err := config.LoadDefaultConfig(ctx)
 	if err != nil {
 		return err
@@ -96,6 +105,7 @@ func run(ctx context.Context, stackName string, args []string) error {
 		ClientRequestToken:  &token,
 		UsePreviousTemplate: ptr(true),
 		Parameters:          params,
+		ResourceTypes:       resourceTypes,
 		Capabilities:        stack.Capabilities,
 		NotificationARNs:    stack.NotificationARNs,
 	})