Add CIDR collapse functionality

[zachsdd]

Adding a CIDR collapse function to terraform for squashing network ranges to avoid use of external data sources (often not encouraged by security policies)

Takes in a list of cidr ranges as a string list and returns a list of superset string values.

[hashicorp-cla]

All committers have signed the CLA.

[mootpt]

@zachsdd could you add docs for new function similar to https://github.com/hashicorp/terraform/blob/main/website/docs/language/functions/cidrnetmask.mdx

[digital-content-events]

📄 Content Checks

Updated: Wed, 30 Aug 2023 19:29:41 GMT

Found 1 error(s)

docs/language/functions/cidrcollapse.mdx

Position	Description	Rule
1:1-1:1	This file is not present in the nav data file at data/language-nav-data.json. Either add a path that maps to this file in the nav data or remove the file. If you want the page to exist but not be linked in the navigation, add a hidden property to the associated nav node.	no-unlinked-pages

[crw]

Thanks for this submission! Ultimately, this function will need to be built as a plugin function provider, as opposed to a function built into Terraform. As such it is waiting for the implementation of plugin function providers. Please see:

• Allow plugins to export custom functions #2771
• Extending terraform with custom functions #27696

There are a number of other CIDR-related function PRs, probably the ideal goal would be to wrap those together into one CIDR function provider. The organization for such an effort remains to be seen. Thanks again for your submission!