amazon-web-services - 在 Terraform 中将 "Application Load Balancer"附加到 "Auto Scaling Group"会出现错误

Question

当在 AWS 控制台中创建 ASG(Auto Scaling 组)时，有一个选项可以选中“从一个或多个负载均衡器接收流量”？

我尝试使用“aws_autoscaling_attachment”资源来做同样的事情，但是我在下面遇到了错误。我可以看到“MyALBWP”出现在控制台中。

ERROR: Failure attaching AutoScaling Group MyWPReaderNodesASGroup with Elastic Load Balancer: arn:aws:elasticloadbalancing:eu-west-2:262702952852:loadbalancer/app/MyALBWP/ef1dd71d87b8742b: ValidationError: Provided Load Balancers may not be valid. Please ensure they exist and try again.

resource "aws_launch_configuration" "MyWPLC" {
  name          = "MyWPLCReaderNodes"
  #count                = 2     Was giving error as min, max size is mentioned in ASG
  #name_prefix          = "LC-"  Error: "name_prefix": conflicts with name
  image_id      =  aws_ami_from_instance.MyWPReaderNodes.id
  instance_type = "t2.micro"
  iam_instance_profile = aws_iam_instance_profile.MyWebInstanceProfile2.name # Attach S3 role to EC2 Instance
  security_groups    = [aws_security_group.WebDMZ.id]  # Attach WebDMZ SG
  user_data          = file("./AutoScaleLaunch.sh")
  lifecycle {
    #prevent_destroy       = "${var.prevent_destroy}"
    create_before_destroy = true
  }
  #   tags = {     NOT VALID GIVES ERROR
  #   Name = "MyWPLC"
  # }

}

# # Create AutoScaling Group for Reader Nodes
# Name: MyWPReaderNodesASGroup
# Launch Configuration : MyWPLC
# Group Size : 2
# Network : Select your VPC
# Subnets : Select your public Subnets
# Receive traffic from Load Balancer   <<< Tried in "aws_autoscaling_attachment" gives 
# Target Group : MyWPInstances
# Health Check : ELB or EC2, Select ELB
# Health check grace period : 60 seconds
# tags name MyWPReaderNodesGroup

resource "aws_autoscaling_group" "MyWPReaderNodesASGroup" {
  name                      = "MyWPReaderNodesASGroup"
  # We want this to explicitly depend on the launch config above
  depends_on = [aws_launch_configuration.MyWPLC]
  max_size                  = 2
  min_size                  = 2
  health_check_grace_period = 60
  health_check_type         = "ELB"
  desired_capacity          = 2
  force_delete              = true
  launch_configuration      = aws_launch_configuration.MyWPLC.id
  vpc_zone_identifier       = [aws_subnet.PublicSubNet1.id, aws_subnet.PublicSubNet2.id]
  target_group_arns = [aws_lb_target_group.MyWPInstancesTG.arn] #  A list of aws_alb_target_group ARNs, for use with Application or Network Load Balancing.
  #target_group_arns = [aws_lb.MyALBWP.id] #  A list of aws_alb_target_group ARNs, for use with Application or Network Load Balancing.
  #error: ValidationError: Provided Target Groups may not be valid. Please ensure they exist and try again.
  # tags = {        NOT REQUIRED GIVES ERROR  : Error : Inappropriate value for attribute "tags": set of map of string required.
  #   Name = "MyWPReaderNodesGroup"
  # }
}

# Create a new load balancer attachment
# ERROR: Failure attaching AutoScaling Group MyWPReaderNodesASGroup with Elastic Load Balancer: arn:aws:elasticloadbalancing:eu-west-2:262702952852:loadbalancer/app/MyALBWP/ef1dd71d87b8742b: 
# ValidationError: Provided Load Balancers may not be valid. Please ensure they exist and try again.

resource "aws_autoscaling_attachment" "asg_attachment_elb" {
  autoscaling_group_name = aws_autoscaling_group.MyWPReaderNodesASGroup.id
  elb                    = aws_lb.MyALBWP.id
}

Answer 1

NOTE on AutoScaling Groups and ASG Attachments: Terraform currently provides both a standalone ASG Attachment resource (describing an ASG attached to an ELB), and an AutoScaling Group resource with load_balancers defined in-line. At this time you cannot use an ASG with in-line load balancers in conjunction with an ASG Attachment resource. Doing so will cause a conflict and will overwrite attachments.

来自 Resource: aws_autoscaling_attachment docs .

你有两个选择:

1. 删除aws_autoscaling_attachment资源
2. 从 aws_autoscaling_group 资源中删除 target_group_arns 参数，从 aws_autoscaling_attachment 资源中删除使用 elb 参数，并将 alb_target_group_arn 添加到 aws_autoscaling_attachment 资源

选项 1 如下所示:

resource "aws_autoscaling_group" "MyWPReaderNodesASGroup" {
  name                      = "MyWPReaderNodesASGroup"
  # We want this to explicitly depend on the launch config above
  depends_on = [aws_launch_configuration.MyWPLC]
  max_size                  = 2
  min_size                  = 2
  health_check_grace_period = 60
  health_check_type         = "ELB"
  desired_capacity          = 2
  force_delete              = true
  launch_configuration      = aws_launch_configuration.MyWPLC.id
  vpc_zone_identifier       = [aws_subnet.PublicSubNet1.id, aws_subnet.PublicSubNet2.id]
  target_group_arns = [aws_lb_target_group.MyWPInstancesTG.arn] #  A list of aws_alb_target_group ARNs, for use with Application or Network Load Balancing.
}

选项 2 如下所示:

resource "aws_autoscaling_group" "MyWPReaderNodesASGroup" {
  name                      = "MyWPReaderNodesASGroup"
  # We want this to explicitly depend on the launch config above
  depends_on = [aws_launch_configuration.MyWPLC]
  max_size                  = 2
  min_size                  = 2
  health_check_grace_period = 60
  health_check_type         = "ELB"
  desired_capacity          = 2
  force_delete              = true
  launch_configuration      = aws_launch_configuration.MyWPLC.id
  vpc_zone_identifier       = [aws_subnet.PublicSubNet1.id, aws_subnet.PublicSubNet2.id]
}

resource "aws_autoscaling_attachment" "asg_attachment_elb" {
  autoscaling_group_name = aws_autoscaling_group.MyWPReaderNodesASGroup.id
  alb_target_group_arn = aws_lb_target_group.MyWPInstancesTG.arn
}