Got TargetGroupVerifyError due to exceeding the limit of DescribeTags

[chatchai-outreach]

Got the following errors when rolling out an application with a load balancer that has 21 target groups.

Failed to verify Service testservice-alb-canary (TargetGroup unknown): operation error Elastic Load Balancing v2: DescribeTags, https response error StatusCode: 400, RequestID: xxxxxx-1234-5678-8901-xxxxxxxx, api error ValidationError: Cannot have more than 20 resources described

AWS ALB API Spec supports 20 ARNs max - https://docs.aws.amazon.com/elasticloadbalancing/latest/APIReference/API_DescribeTags.html

Resource Arns.member.N - The Amazon Resource Names (ARN) of the resources. You can specify up to 20 resources in a single call.

argo-rollouts/utils/aws/aws.go

Lines 173 to 186 in 3321a89

	tagsIn := elbv2.DescribeTagsInput{
	ResourceArns: tgARNs,
	}
	tagsOut, err := c.ELBV2.DescribeTags(ctx, &tagsIn)
	if err != nil {
	return nil, err
	}
	for _, tagDesc := range tagsOut.TagDescriptions {
	for _, tag := range tagDesc.Tags {
	if _, ok := tgMetaMap[*tagDesc.ResourceArn]; ok {
	tgMetaMap[*tagDesc.ResourceArn].Tags[*tag.Key] = *tag.Value
	}
	}
	}

should DescribeTargetGroups be called with pagination and/or DescribeTags requested in batches?