fix(unikernels): reject single quotes in Linux init args to prevent boot-cmdline corruption - #898
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…oot-cmdline corruption parseCmdLine() wrapped multi-word arguments in unescaped single quotes for urunit compatibility. An argument containing both a space and a single quote, for example sh -c "echo it's broken", produced an unbalanced quote sequence, corrupting the token-boundary parsing that urunit performs on /proc/cmdline and causing the guest init process to receive the wrong arguments. Since urunit's cmdline parser lives outside this repo and its escaping semantics are unknown, reject arguments containing a single quote with a clear error instead of guessing an escaping scheme. Fixes urunc-dev#897
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Summary
parseCmdLine() in pkg/unikontainers/unikernels/linux.go wraps multi-word arguments in single quotes so urunit can recover argument boundaries from the guest's boot cmdline. It does this with plain string concatenation and does not escape quote characters already present in the argument.
If an argument contains both a space and a single quote, for example sh -c "echo it's broken", the wrap produces an unbalanced quote sequence such as 'sh' 'echo it's broken', which corrupts the token boundaries that urunit parses out of /proc/cmdline. The guest init process can then receive the wrong arguments with no error surfaced to the user.
Since urunit's own cmdline parser lives outside this repo and its escaping rules are not known here, this change rejects arguments containing a single quote with a clear error instead of guessing an escaping scheme that might not match what urunit actually supports.
Fixes #897
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