add hip-0019

Signed-off-by: Danilo Patrucco <[email protected]>

hips/hip-0019.md

@@ -0,0 +1,46 @@
+---
+hip: 0019
+title: "Add Exclude File Option to Helm Lint Command"
+authors: Danilo Patrucco
+created: "2024-07-03"
+type: "feature"
+status: "draft"
+---
+
+## Abstract 
+This proposal suggests enhancing the `helm lint` command to exclude specific files or patterns from linting through a `.helmlintignore` file, similar to `.gitignore` or `.helmignore`. Additionally, a `--lint-ignore-file` flag will be introduced to specify alternative locations for the `.helmlintignore` file, facilitating its use in projects with multiple sub-charts. 
+## Motivation 
+In large Helm charts, certain files or configurations may deviate from standard linting rules but are accepted by the maintainers. Currently, `helm lint` evaluates all files within a chart, leading to irrelevant warnings or errors. An exclusion option and the ability to specify ignore file locations would allow developers to better manage lint results. 
+## Rationale 
+This proposal aims to give developers and integrators greater control over the linting process by allowing exclusions for: 
+- Files imported or managed by third parties that are not directly editable. 
+- Files that may not conform to static linting rules. 
+- Files containing intentional deviations from standard practices due to specific deployment scenarios. 
+The `.helmlintignore` file will support simple patterns to match files and directories for easy exclusion management. The `--lint-ignore-file` flag enhances this by allowing centralized management of lint exclusions in complex projects. 
+## Specification 
+### `.helmlintignore` File Format 
+The `.helmlintignore` file allows chart developers to specify filenames or glob patterns to exclude from linting. The format is straightforward, with one pattern per line, similar to `.gitignore` files. 
+#### Example 
+ ``` 
+# .helmlintignore file example 
+template/test/test.sh  # Exclude this file from linting 
+template/test/test.yaml  {{template "fullname" .}}  # Exclude this specific line from findings in this specific file (error is still detected but no output is generated)
+``` 
+Patterns can be a simple `path/to/my/file` to exclude a whole file, or `path/to/my/file line.triggering.error` to ignore specific error-triggering lines in the error output. 
+### Command Behavior 
+When `helm lint` is executed, it will first check for the presence of a `.helmlintignore` file in the chart directory or at a specified location using the `--lint-ignore-file` flag. This allows the command to parse the file and exclude any files or directories matching the patterns. Additionally, if a file contains a specific error line that matches a pattern, that error will not be displayed. 
+## Backwards Compatibility 
+This proposal introduces no breaking changes. Charts without a `.helmlintignore` file or without using the `--lint-ignore-file` flag will function as they currently do. 
+## Security Implications 
+No significant security implications are expected. The `.helmlintignore` file is processed locally by `helm lint` without modifying chart content or involving network activity. 
+## How to Teach This 
+Documentation for the `.helmlintignore` file and the `--lint-ignore-file` flag will be included in the official Helm docs under the `helm lint` section. Examples and common patterns will be provided to aid new users. 
+## Reference Implementation 
+No reference implementation yet. Post-acceptance, an issue will be created in the Helm community GitHub repository to add the HIP 
+## Open Issues 
+- Finalizing an effective and user-friendly pattern syntax for the `.helmlintignore` file. 
+- Potential inclusion of in-file annotations for temporarily excluding specific chart sections from linting. 
+## Rejected Ideas 
+None at this time. 
+## References 
+- This proposal is in line with the practices outlined in [HIP-0001](https://github.com/helm/community/blob/master/hips/hip-0001.md).