Modify pre-existing ELB by Terraform-CodePudding

I would like to import the pre-installed ELB which is not made by Terraform, As far as I know, provisioned EC2s (not created by Terraform) are modified with no problems.

Please refer to: https://www.youtube.com/watch?v=Abv3CHS4HTE

All I want to know is to enable provisioned ELB with the Access logs. (* I don't want to provision a new ELB)

Following is the code I run.

    data "aws_elb_service_account" "main" {}
    
    resource "aws_s3_bucket" "elb_logs" {
      bucket = "<BucketName>"
      acl    = "private"
    
      policy = <<POLICY
    {
      "Id": "Policy",
      "Version": "2012-10-17",
      "Statement": [
        {
          "Action": [
            "s3:PutObject"
          ],
          "Effect": "Allow",
          "Resource": "arn:aws:s3:::<BucketName>/AWSLogs/*",
          "Principal": {
            "AWS": [
              "${data.aws_elb_service_account.main.arn}"
            ]
          }
        }
      ]
    }
    POLICY
    }
    
    resource "aws_lb" "foobar" {
      arn                = "arn:aws:elasticloadbalancing:ap-northeast-1:<AccountName>:loadbalancer/app/<ELBName>/7c6a359c72a9a02e"
      name               = "<ELBName>"
      internal           = false
      load_balancer_type = "application"
        subnets                    = [
            "<Subnet-1Name>",
            "<Subnet-2Name>",
        ]
      access_logs {
        bucket   = "${aws_s3_bucket.elb_logs.bucket}"
      }
    }

CodePudding user response：

You need to import the existing load balancer into the terraform state:

$ terraform import aws_lb.foobar LB_ARN

(replace LB_ARN with the ARN of the load balancer).

CodePudding user response：

You first need to import the resource in Terraform. In your case for ELB, first, create a terraform resource block for ELB like this-

resource "aws_elb" "test" {
  name = "test_elb"
}

And, Import the resource using the command- terraform import aws_elb.test test_elb

It'll create terraform statefile. You can confirm the state using terraform state list command.

Now use the config from the state file in your resource block to exactly match the remote resource state.

Do terraform plan to check.

That's all, Now make any change in your resource block. Your resource is now managed by terraform.