feat: add TESTING environment variable feature gate for microvm-init #2264
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Add support for TESTING environment variable that gets passed to the kernel command line as melange.testing=<value>. This allows microvm-init to conditionally enable/disable features during testing and development. The TESTING variable must be a number (0-9, etc.) or empty string. String values are rejected with a warning to prevent injection issues. Usage: TESTING=1 melange build mypackage.yaml In microvm-init, the value can be read from /proc/cmdline as melange.testing
egibs
reviewed
Dec 9, 2025
stevebeattie
reviewed
Dec 9, 2025
Member
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Modulo the comments, this looks good and works as expected. Thanks! |
- Change log level from DEBUG to INFO for better visibility - Remove empty string handling to simplify logic - Update comment to clarify expected values (0 for disabled, non-zero for enabled) Addresses feedback from PR chainguard-dev#2264 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
egibs
approved these changes
Dec 10, 2025
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Summary
Add support for
TESTINGenvironment variable that gets passed to the kernel command line asmelange.testing=<value>. This allows us to feature within staging to test things. In particular, we'd like to make some changes to microvm-init.Changes
pkg/container/qemu_runner.goto readTESTINGenvironment variableTESTINGis a number (or empty string) to prevent injection issuesmelange.testing=<value>Usage
Security
The implementation validates that
TESTINGonly accepts numeric values (or empty string) to prevent kernel command line injection attacks. String values are rejected with a warning message.Test plan
TESTING=1and verifymelange.testing=1appears in kernel cmdlineTESTING=fooand verify warning is logged and value is not passedTESTING=and verifymelange.testing=is passed to kernelTESTINGenv var and verify no changes to existing behavior