resource/aws_datasync_agent: Add support for VPC Endpoints

.changelog/16207.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/aws_datasync_option: Add `private_link_endpoint`, `security_group_arns`, `subnet_arns` and `vpc_endpoint_id` arguments
+```

aws/internal/service/datasync/finder/finder.go

@@ -7,6 +7,34 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
 )
 
+func AgentByARN(conn *datasync.DataSync, arn string) (*datasync.DescribeAgentOutput, error) {
+	input := &datasync.DescribeAgentInput{
+		AgentArn: aws.String(arn),
+	}
+
+	output, err := conn.DescribeAgent(input)
+
+	if tfawserr.ErrMessageContains(err, datasync.ErrCodeInvalidRequestException, "does not exist") {
+		return nil, &resource.NotFoundError{
+			LastError:   err,
+			LastRequest: input,
+		}
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	if output == nil {
+		return nil, &resource.NotFoundError{
+			Message:     "Empty result",
+			LastRequest: input,
+		}
+	}
+
+	return output, nil
+}
+
 func TaskByARN(conn *datasync.DataSync, arn string) (*datasync.DescribeTaskOutput, error) {
 	input := &datasync.DescribeTaskInput{
 		TaskArn: aws.String(arn),

aws/internal/service/datasync/waiter/status.go

@@ -8,6 +8,26 @@ import (
 	"github.com/terraform-providers/terraform-provider-aws/aws/internal/tfresource"
 )
 
+const (
+	agentStatusReady = "ready"
+)
+
+func AgentStatus(conn *datasync.DataSync, arn string) resource.StateRefreshFunc {
+	return func() (interface{}, string, error) {
+		output, err := finder.AgentByARN(conn, arn)
+
+		if tfresource.NotFound(err) {
+			return nil, "", nil
+		}
+
+		if err != nil {
+			return nil, "", err
+		}
+
+		return output, agentStatusReady, nil
+	}
+}
+
 func TaskStatus(conn *datasync.DataSync, arn string) resource.StateRefreshFunc {
 	return func() (interface{}, string, error) {
 		output, err := finder.TaskByARN(conn, arn)

aws/internal/service/datasync/waiter/waiter.go

@@ -10,6 +10,23 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
 )
 
+func AgentReady(conn *datasync.DataSync, arn string, timeout time.Duration) (*datasync.DescribeAgentOutput, error) {
+	stateConf := &resource.StateChangeConf{
+		Pending: []string{},
+		Target:  []string{agentStatusReady},
+		Refresh: AgentStatus(conn, arn),
+		Timeout: timeout,
+	}
+
+	outputRaw, err := stateConf.WaitForState()
+
+	if output, ok := outputRaw.(*datasync.DescribeAgentOutput); ok {
+		return output, err
+	}
+
+	return nil, err
+}
+
 func TaskAvailable(conn *datasync.DataSync, arn string, timeout time.Duration) (*datasync.DescribeTaskOutput, error) {
 	stateConf := &resource.StateChangeConf{
 		Pending: []string{datasync.TaskStatusCreating, datasync.TaskStatusUnavailable},