The s3 backend does not respect the NO_PROXY variable

[Yantrio]

OpenTofu Version

1.6.0

OpenTofu Configuration Files

terraform {
  backend "s3" {
    bucket="tf-state-test"
    region="eu-central-1"
    key="test/test.tfstate"
  }
}

Debug Output

External gist link: Debug Output

Expected Behavior

OpenTofu should respect the NO_PROXY environment variable, specifically for requests to http://169.254.169.254. The NO_PROXY variable is set as follows:

export NO_PROXY="169.254.169.254"

Actual Behavior

OpenTofu only honors HTTP_PROXY and HTTPS_PROXY variables, ignoring the NO_PROXY setting. As a result, certain local requests use a proxy when they shouldn't.

Steps to Reproduce

1. Run terraform init

Additional Context

export HTTP_PROXY="http://proxy:3128"
export HTTPS_PROXY="http://proxy:3128"
export NO_PROXY="169.254.169.254"

References

• Original report: hashicorp/terraform#33987
• Original functionality was added: backend/s3: add http_proxy and related arguments #33748
• Looks like this is an issue in aws-sdk-go-base as mentioned in this comment

[tarruda]

Even though the issue appears to be in aws-sdk-go-base, we can probably fix this locally by resetting the HTTP_PROXY /HTTPS_PROXY env vars if NO_PROXY is set. I can investigate/tackle this one @cube2222 (I had misunderstood the meaning of NO_PROXY, so this won't work)