- In Alpine Linux containers (commonly used as Docker base images),
standard DNS resolution is provided by **musl**, a lightweight C
standard library (libc). Musl implements DNS lookups via
`getaddrinfo()`, which queries AAAA (IPv6) records first.
- Problem: DNS did not work correctly **inside containers**. Any
system command attempting to resolve hostnames
(e.g., `ping dynamodb-admin`) **failed** when the DNS server
responded NXDOMAIN for AAAA records, even if A (IPv4) records
existed. Explicitly forcing IPv4 (`ping -4dynamodb-admin`) worked
correctly, showing the issue is specific to musl’s IPv6-first behavior.
- Consequence: In IPv4-only environments, Alpine-based containers
cannot resolve hostnames using standard tools or libraries.
Applications relying on `getaddrinfo()` fail with ENOTFOUND,
breaking networking and inter-container communication.
- Root cause: Following RFC 8305 / RFC 6724, musl treats NXDOMAIN
for AAAA as “hostname does not exist” and does not fallback to A
(IPv4) records.
- Fix: The Apple Container DNS engine now behaves as follows:
* If an **A record exists**, AAAA queries return **NOERROR with empty
answer (NODATA)**.
* If neither **A nor AAAA** exist, NXDOMAIN is returned.
This ensures that Alpine-based containers in IPv4-only networks can
correctly resolve hostnames inside containers without modifying
container images or application code.
- Closes#752.
- Currently, there is no way to specify a custom MAC address for a
container's network interface and the MAC address is auto-generated by
the system.
- Use Cases
- **Network Testing**: Developers testing network-dependent applications
that need predictable MAC addresses
- **License Management**: Running containerized software with MAC-based
license keys
- **Network Automation**: Scripts and tools that expect specific MAC
addresses for configuration
- **Debugging**: Consistent MAC addresses across container restarts for
easier troubleshooting
- Closes#508.
## Type of Change
- [ ] Bug fix
- [x] New feature
- [ ] Breaking change
- [ ] Documentation update
## Motivation and Context
Adds a `container volume prune` command that removes volumes with no
container references and reports the amount of disk space reclaimed.
This helps users clean up unused volumes and easily reclaim disk space.
Also updates the `volume delete` documentation to clarify and highlight
how the `--all` flag works.
## Testing
- [x] Tested locally
- [x] Added/updated tests
- [x] Added/updated docs
- Part of #653.
- No need for `defaultCommand` since ContainerService startup will write
a new launchd plist with the `start` subcommand included.
## Type of Change
- [ ] Bug fix
- [ ] New feature
- [ ] Breaking change
- [ ] Documentation update
## Motivation and Context
Allows us to add commands to support post-installation, migration, etc.
## Testing
- [x] Tested locally
- [ ] Added/updated tests
- [ ] Added/updated docs
- Closes#615.
Improves project organization. Separates service so it can be tested and
used separately from the executable target. No functional changes.
- Closes#557.
- Breaking change: removes `.upToNextOption` for labels on volumes as
this is not what is done for containers, and it forces the argument to
precede the options if a label is supplied, which is non-intuitive.
## Type of Change
- [ ] Bug fix
- [x] New feature
- [x] Breaking change
- [x] Documentation update
## Motivation and Context
Consistent features and UX across managed resources.
## Testing
- [x] Tested locally
- [x] Added/updated tests
- [x] Added/updated docs
Define a `UnpackStrategy` function type in the `SnapshotStore` to give
more control over how an image is unpacked.
Previously, we were creating a 512 GB sparse block file for the initial
file system of a container, which is overkill.
With this change, the vminit image is unpacked to a smaller block file,
while container images are unpacked to the 512 GB block
Follows the same pattern as
https://github.com/apple/container/blob/main/Sources/Helpers/RuntimeLinux/RuntimeLinuxHelper.swift#L71
Signed-off-by: Aditya Ramani <a_ramani@apple.com>
See discussion below for example. For multiple network interfaces in a
single container we'll want to integrate against a containerization that
includes apple/containerization#156.
The change bumps the containerization dependency to 0.2.0 and addresses
the breaking API changes.
```console
% container network
OVERVIEW: Manage container networks
USAGE: container network <subcommand>
OPTIONS:
--version Show the version.
-h, --help Show help information.
SUBCOMMANDS:
create Create a new network
delete, rm Delete one or more networks
list, ls List networks
inspect Display information about one or more networks
See 'container help network <subcommand>' for detailed help.
```
Rado Kubiak | Rado x Tech