fix (gke): comment out authorized_cidr in GKE blueprints and validate authorised_cidr

[saumyasharma03]

comment out authorized_cidr in GKE blueprints and validate authorised_cidr

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• Fork your PR branch from the Toolkit "develop" branch (not main)
• Test all changes with pre-commit in a local branch #
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• Add or modify unit tests to cover code changes
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• Update all applicable documentation
• Follow Cluster Toolkit Contribution guidelines #

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request improves the security and reliability of GKE blueprint deployments by preventing the use of placeholder CIDR values. It introduces a formal validation mechanism for CIDR inputs and updates existing example configurations to require explicit user configuration, reducing the risk of misconfigured network access controls.

Highlights

• GKE Blueprint Updates: Commented out the 'authorized_cidr' variable in various GKE example blueprints to prevent accidental deployment with placeholder values.
• New CIDR Validator: Implemented a new 'cidr' validator in the toolkit to ensure that 'master_authorized_networks' entries are correctly formatted as valid CIDR blocks.
• Validation Integration: Updated the GKE cluster module metadata and Terraform variables to enforce CIDR validation, ensuring robust configuration checks.
• Testing and Tooling: Added comprehensive unit tests for the new validator and updated the configuration validation script to handle the commented-out CIDR variables during testing.

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[gemini-code-assist]

Code Review

This pull request introduces a new CIDR validator (CIDRValidator) in Go to validate CIDR blocks in blueprints, registers it, and adds corresponding unit tests. It also adds a Terraform-level validation block to the master_authorized_networks variable in the GKE cluster module, comments out placeholder CIDR values in several example blueprints, and updates the configuration validation script to handle these placeholders. The review feedback highlights several improvement opportunities: ensuring that non-string types, missing object keys, and missing map keys in the CIDR validator return explicit errors rather than silently succeeding, and refining the grep pattern in the validation script to avoid matching commented-out lines.

[saumyasharma03]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a new CIDR validator to verify IP CIDR blocks in module metadata and variables. It implements the CIDRValidator in Go, registers it, adds corresponding unit tests, and updates the configuration validation script to handle the authorized_cidr variable. Additionally, it comments out the placeholder <your-ip-address>/32 in several GKE example blueprints and adds a Terraform validation block to the master_authorized_networks variable in the GKE cluster module. Feedback was provided to explicitly handle null values in the Terraform variable validation to prevent potential evaluation failures.