fix(kubernetes): Only filter out files that contain Helm built-in variables and functions

[eirmich]

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Description

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

Currently Kubernetes files that contain {{ are assumed to be part of a Helm chart, which in turn excludes them from analysis. However, this is not always the case, an example as described in #5643 (comment).

This PR filters out only files that include Helm built-in variables or functions, namely .Release, .Values, if, end and with.

Fixes #5643

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes

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Generated description

Below is a concise technical summary of the changes proposed in this PR:

Modifies the Kubernetes YAML parser to improve the detection of Helm templates. Updates the load function in k8_yaml.py to use regex patterns for identifying Helm-specific variables and functions. Adds a new test case in test_k8_yaml.py to verify the correct handling of non-Helm templates containing curly braces. Includes a sample YAML file not_helm_configmap.yaml for testing purposes.

Topic	Details
Test coverage	Adds test cases to verify the updated Helm template detection logic Modified files (2) tests/kubernetes/parser/examples/yaml/not_helm_configmap.yaml tests/kubernetes/parser/test_k8_yaml.py Latest Contributors(2) User Commit Date gruebel feat-kubernetes-suppor... April 02, 2023 [email protected] Exclude-raw-HELM-templ... February 22, 2022
Helm detection	Refines the logic for identifying Helm templates in Kubernetes YAML files Modified files (1) checkov/kubernetes/parser/k8_yaml.py Latest Contributors(2) User Commit Date bo156 feat-general-Add-resou... July 19, 2023 gruebel feat-general-support-U... July 10, 2023

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