## What
Add a `DNS.validate()` method that verifies all nameserver entries are
valid IPv4 or IPv6 addresses. The method is called from
`Vminitd.configureDNS()` before applying the configuration.
## Why
Closes#467. Currently, any arbitrary string can be passed as a
nameserver in `DNSConfiguration`, which silently results in an invalid
`/etc/resolv.conf` inside the container. Hostname strings like
`dns.example.com` would be written to resolv.conf but would not work as
nameservers.
## How
- Added `DNS.validate() throws` method in `DNSConfiguration.swift` that
iterates over all nameservers and attempts to parse each as either an
`IPv4Address` or `IPv6Address` (using the existing parsers in
`ContainerizationExtras`)
- Added `import ContainerizationExtras` to `DNSConfiguration.swift` (the
`Containerization` target already depends on `ContainerizationExtras`)
- Called `config.validate()` at the start of `Vminitd.configureDNS()` so
validation happens before any GRPC call
## Testing
Added 6 new unit tests in `DNSTests.swift`:
- ✅ Valid IPv4 nameservers accepted
- ✅ Valid IPv6 nameservers accepted
- ✅ Mixed IPv4/IPv6 nameservers accepted
- ✅ Empty nameserver list accepted
- ❌ Hostname rejected
- ❌ Invalid address rejected
## Checklist
- [x] Tests added
- [x] No breaking changes to existing API (validate() is a new method,
existing init is unchanged)
- [x] Follows existing patterns (uses ContainerizationExtras IP address
types, ContainerizationError for errors)
Signed-off-by: Maxime Grenu <maxime.grenu@gmail.com>
This change adds documentation to quite a few existing public types that
didn't have a blurb before.
Additionally, this fixes a couple things that I think either didn't make
sense when going to document them:
- Rename ConnectionStream to VsockConnectionStream. This type only
functions for vsock connections.
- Deletes NsLock+Closure. This was not used anywhere.
- Rename ContainerizationOCI/Config.swift to ImageConfig.swift.
Signed-off-by: Danny Canter <danny_canter@apple.com>
Maxime Grenu