[Bug]: Fixed-response in ALB listener rule fails with multibyte characters exceeding 342 characters

[akhn1004]

Terraform Core Version

1.7.5

AWS Provider Version

5.5.2

Affected Resource(s)

• aws_lb_listener_rule

Expected Behavior

Can be configured with 1024 characters (even multi byte characters).

Actual Behavior

Failure in terraform plan.

Error: expected length of action.0.fixed_response.0.message_body to be in the range (0 - 1024), got ......

Relevant Error/Panic Output Snippet

│ Error: expected length of action.0.fixed_response.0.message_body to be in the range (0 - 1024), got １２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２
│
│   with aws_lb_listener_rule.test,
│   on share_elb_main.tf line 94, in resource "aws_lb_listener_rule" "test":
│   94:       message_body = "１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２"

Terraform Configuration Files

resource "aws_lb_listener_rule" "test" {
  listener_arn = aws_alb_listener.test.arn
  priority     = 100
  action {
    type = "fixed-response"

    fixed_response {
      content_type = "text/plain"
      message_body = "１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２"
      status_code  = 200
    }
  }

Steps to Reproduce

1. Create an empty AWS ALB.
2. Create an empty AWS ELB listener.
3. Create an empty AWS ELB target group.
4. Create a AWS ELB listerner rule with fixed_response. Set 342 characters in message body of fixed_response.

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

None

[github-actions]

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[akhn1004]

I set default_action / fixed_response to ELB listener and set more than 342 characters as well and it failed with plan as well.

[justinretzolk]

@akhn1004 👋 Thanks for taking the time to raise this! It looks like the validation is checking byte length rather than character length (removing a couple of characters to get it under 1024 bytes made the validation pass). Are you able to do the same from the API without issue?

$ export TEST_STRING='１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０ １２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６ ７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２３４５６７８９０１２'

# byte count
$ echo "$TEST_STRING" | wc -c
    1028

# word count
$ echo "$TEST_STRING" | wc -m
     344

[pf-siedler]

I had same issue.

I tried it on managed console.
I created listener rule contain multibyte strings (600 characters / 1800 bytes). It passed.

but, terraform validation failed.

$ terraform plan
╷
│ Error: expected length of action.0.fixed_response.0.message_body to be in the range (0 - 1024), got ああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああ
│ 
│   with aws_lb_listener_rule.multibyte_string,
│   on main.tf line 47, in resource "aws_lb_listener_rule" "multibyte_string":
│   47:       message_body = "ああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああああ"
│ 
╵

---

That validation is defined here.

terraform-provider-aws/internal/service/elbv2/listener_rule.go

Line 205 in c4fa4f5

ValidateFunc: validation.StringLenBetween(0, 1024),

StringLenBetween is defined here.
https://github.com/hashicorp/terraform-plugin-sdk/blob/843f27434cd7d30104dbee895e5767a61239ccea/helper/validation/strings.go#L82

len() counts byte size (not character).

[seth-peters97101]

This has been a probelm for over 4 years, can this be prioritized?

See:

• action.fixed_response.message_body in aws_lb_listener_rule is validated not by length, but by bytes #19846 (June 2021)
• ELBv2 FixedResponse with message_body (<= 1024 chars && > 1024bytes) cannot be registered  #22949 (February 2022)

There's also an open PR in the terraform plugin sdk repo: hashicorp/terraform-plugin-sdk#985