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Permission allow-fs-* to resolve env variables

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#65,422 1 comment 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
55/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Active
Tech stack
javascript
Domain
cli, security

Research direction

Start by tracing how Node.js parses --allow-fs-read and --allow-fs-write from direct arguments, NODE_OPTIONS, and configuration files. Check the existing permission-option tests and add coverage for exact environment-variable values in string and array forms. Done means supported permission inputs resolve environment variables consistently, including behavior when a variable is unset.

Written by the indexing model from the issue text.

Description

feature request permission
What is the problem this feature will solve?

While it is possible to pass values of env variables when calling node directly

node --permission --allow-fs-read=$HOME

there are other ways to set permissions (in config file or via NODE_OPTIONS) that don't go through the shell first.

I'd like to make it possible for all methods of passing in permissions to support using environment variables.

{
  "nodeOptions": {
    "--permission": true,
    "--allow-fs-read": [
      "$HOME"
    ]
  }
}
What is the feature you are proposing to solve the problem?

Pseudocode:

    const replaceEnvVar = (value) => {
      const envVarMatch = value.match(/^\$([A-Z_][A-Z0-9_]*)$/i)
      if (envVarMatch) {
        const envVarName = envVarMatch[1]
        if (process.env[envVarName] !== undefined) {
          return process.env[envVarName]
        } else {
          console.error(
            `[LavaMoat] Environment variable "${envVarName}" referenced in config but not found in environment`
          )
        }
      }
      return value
    }

    for (const key of ['--allow-fs-read', '--allow-fs-write']) {
      if (Array.isArray(configOptions[key])) {
        configOptions[key] = configOptions[key].map(replaceEnvVar)
      } else if (typeof configOptions[key] === 'string') {
        configOptions[key] = replaceEnvVar(configOptions[key])
      }
    }
What alternatives have you considered?

I've considered more advanced support where this would also work:

{
  "nodeOptions": {
    "--permission": true,
    "--allow-fs-read": [
      "/home/${MY_USER}/some/place/else"
    ]
  }
}

but it seems unnecessarily complex and error prone to be worth it IMHO.

Dominant language
JavaScript
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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