Upgrading to Terraform v1.5

Terraform v1.5 is a minor release in the stable Terraform v1.0 series.

Terraform v1.5 honors the Terraform v1.0 Compatibility Promises, but there are some behavior changes outside of those promises that may affect a small number of users. Specifically, the following updates may require additional upgrade steps:

• End of support for older macOS releases
• Linux DNS resolver changes

See the full changelog for more details. If you encounter any problems during upgrading which are not covered this guide, please start a new topic in the Terraform community forum to discuss it.

End of support for older macOS releases

Terraform v1.5 will be the last release supported on macOS 10.13 High Sierra and macOS 10.14 Mojave, both of which are no longer maintained by Apple.

Terraform v1.5 itself supports these older macOS versions, but we strongly recommend upgrading during the v1.5 release period so that you'll be ready to use Terraform v1.6 once it is released.

Linux DNS resolver changes

Terraform on Linux uses a built-in DNS resolver rather than using the DNS resolver from the platform's C library, because this allows Terraform to run on systems with many different C libraries.

In Terraform v1.5, the DNS resolver will now notice when you have set the trust-ad option in your /etc/resolve.conf file, and will respond by setting the "authentic data" option in outgoing DNS requests to better match the behavior of the GNU libc DNS resolver.

Terraform does not pay any attention to the corresponding option in responses, but some DNSSEC-aware recursive resolvers return different responses when the request option isn't set. This should therefore avoid some potential situations where a DNS request from Terraform might get a different response than a similar request from other software on your system.

We don't expect this behavior change to be significant for most Terraform users.

Note that this change affects only DNS requests made by Terraform CLI itself, and not requests made by providers. Provider plugins are separate programs which handle DNS resolution themselves and so may have different behavior.