- Fixes#776
- Release 2.9.0 of `grpc-swift-nio-transport` fixes
the HTTP/2 initialization race that required a
`HTTP2ConnectBufferingHandler` for the vminitd
API. This upgrades the dependency and eliminates
the workaround.
apple/containerization currently runs containers in per-container VMs on
macOS hosts via Virtualization.framework. This adds a second VMM backend
so the same Swift orchestration layer (LinuxContainer / LinuxPod /
Vminitd gRPC contract) runs on Linux hosts via cloud-hypervisor + KVM.
**CloudHypervisor Swift package** (`Sources/CloudHypervisor/`) — a thin
client for cloud-hypervisor's REST-over-UDS API, layered on
AsyncHTTPClient. Endpoints cover VMM / VM lifecycle / hotplug (disk, fs,
net, vsock, remove-device). Cross-platform (compiles on macOS for unit
tests; consumed at runtime only by the Linux side of Containerization).
**CH backend in Containerization** — one cloud-hypervisor subprocess per
VM, gated behind `#if os(Linux)`. CHVirtualMachineManager /
CHVirtualMachineInstance mirror the VZ shape behind the existing
VirtualMachineManager / VirtualMachineInstance protocol. CHProcess and
VirtiofsdProcess manage the binaries; CHHotplugProvider handles
virtio-blk and virtio-fs runtime hotplug (with one virtiofsd per unique
source-hash tag, refcounted across containers).
**Linux host networking** — BridgeManager brings up a Linux bridge with
an IPv4 subnet and (opt-in via `--enable-nat`) iptables MASQUERADE +
scoped FORWARD rules. LinuxBridgedNetwork enslaves a fresh TAP per
container to the bridge. State is recorded under `/run/containerization`
so `cctl bridge delete` reverses exactly what create did. Bridge
teardown verifies the link kind via sysfs to refuse deleting non-bridge
interfaces.
**cctl run / bridge** — end-to-end Linux container run path (image pull,
ext4 rootfs assembly, VM boot, container exec) plus `cctl bridge
create|delete` for the host network plumbing.
**Build & dist** — `make linux-build` / `make linux-integration` build
and exercise the host side inside an apple/container `--virtualization`
dev container. `make dist-x86_64` produces a deployment tarball (cctl +
cloud-hypervisor + virtiofsd + initfs + kernel) cross-compiled from the
aarch64 dev container; pipeline documented in `docs/x86_64-build.md`.
Static-musl C deps and the Zig cross compiler are pinned by SHA256.
The host orchestrator runs as root. Per-VM runtime state lives under
`/run/containerization/ch/<UUID>` with mode 0700; UDS sockets inside are
bound with mode 0600. Vminitd's gRPC channel inherits that trust
boundary — socket-file perms are the auth.
Sandbox flags are upstream-secure by default. Two per-component opt-outs
exist for the apple/container dev-container case (where the host seccomp
profile SIGSYS-kills CH and virtiofsd):
- `CONTAINERIZATION_NO_CH_SECCOMP=1` — `cloud-hypervisor --seccomp
false`.
- `CONTAINERIZATION_NO_VIRTIOFSD_SANDBOX=1` — `virtiofsd --sandbox
none`. Each emits a one-shot `logger.warning` at process start. Legacy
alias `CONTAINERIZATION_RELAXED_SANDBOX=1` flips both. cctl spawns both
binaries with `setsid` and a minimal env allowlist (PATH / HOME /
RUST_LOG / RUST_BACKTRACE) so the parent's secrets don't leak to
children.
`make linux-integration` runs the cross-platform integration suite
against a real cloud-hypervisor VM inside the dev container. Linux runs
the cross-platform subset (`process true`/`false`/`echo hi`, virtiofs
round-trip, hotplug); the macOS suite is unchanged.
Signed-off-by: michael_crosby <michael_crosby@apple.com>
The `--log-level` option when running the agent sub-command for vminitd
was being silently ignored cause of the way the agent is being run. As a
workaround we need to read `/proc/self/cmdline` to get the right args
Extends the network plumbing to support per-interface IPv6 address
configuration.
The `Interface` protocol supports `ipv6Address` and `ipv6Gateway`.
The agent's networking RPCs carry per-family fields via new
`InterfaceAddress`, `LinkRoute`, and `DefaultRoute` types in
`ContainerizationExtras`.
`NetlinkSession` adds IPv6 methods for address and route operations.
---------
Co-authored-by: michael_crosby <michael_crosby@apple.com>
Co-authored-by: Michael Crosby <crosbymichael@gmail.com>
- Closes#712.
- Replace synchronous `write()` calls in
`BidirectionalRelay` with non-blocking I/O
and `DispatchSourceWrite` backpressure
handling. Under concurrent vsock proxy load,
a single blocked write on the shared serial
dispatch queue would freeze all relay
connections permanently, including unrelated
new connections.
- Set relay file descriptors to `O_NONBLOCK`
and handle `EAGAIN` by suspending reads and
installing a write source to drain pending data.
- Give each `BidirectionalRelay` its own serial queue
instead of sharing one from `UnixSocketRelayManager`,
eliminating cross-connection blocking.
- Resume suspended read sources before cancelling
in `stop()` — GCD does not deliver cancel handlers
on suspended dispatch sources, which caused file
descriptor and memory leaks on teardown under
backpressure.
- Guard-unwrap `buf.baseAddress` in
`drainPendingWrite`.
External Swift Package Manager consumers can only see products declared
in the top-level `Package.swift`. The `VminitdCore` library was declared
inside the `vminitd` subpackage, so it was impossible to build a custom
`vminitd` against it via a URL dependency on `containerization`. This
change moves the `VminitdCore` to the top-level `Package.swift`.
This pull request enhances the handling of file and directory copy
operations in Linux containers, particularly by improving destination
path resolution and error handling for the `copyIn` operation with the
`Stat RPC`
This PR is needed for
[container#1190](https://github.com/apple/container/pull/1190)
- We were using Swift 6.3, which can pick up a newer version that is out
of sync of both the `.swift-version` file for the project and the Swift
SDK downloaded in the Dockerfile.
The stdout and stdin IOPairs in TerminalIO share the same Terminal fd.
Closing stdin first would close the Terminal, causing stdout to read -1
from fileDescriptor and fail to unregister from epoll. This left stale
handler closures (capturing the IOPair) in ProcessSupervisor.handlers
indefinitely.
Additionally, vsock sockets created in TerminalIO.start() with
closeOnDeinit disabled were never closed if the process exited before
attach() created IOPairs.
If someone wanted to use a custom guest agent/guest image in general the
overhead we chose is kind of a nuisance.. This allows the values to be
configurable, and raises the default to 128, and vminitds cgroup
monitoring to 80.
Add `Stat` RPC to vminitd.
`Stat` RPC is used to stat file system objects in the VM. It accepts the
path to the object (resolved against VM root) and returns the stat
result.
- Setting 6.3 in the .swift-version is pulling in 6.3.1 but we can't go
there until there is a docker image for it, or Linux build breaks.
Alternatively we'd need to have different Swift SDKs for Linux musl
build vs macOS.
Sets `memory.low` for `vminitd` cgroup to make kernel avoid reclaiming
its memory under high memory pressure. Even if the container process
runs in memory cgroup, consuming lots of page cache can lead to
reclaiming `vminitd`'s page cache memory , which hangs the `vminitd`.
Setting `memory.low` makes kernel avoid reclaiming `vminitd`'s page so
that we can guarantee the proper `vminitd` operation under high memory
pressure.
- Closes#51. Again.
- No real notable API changes. The largest change code-wise is in
Vminitd. The connection loop is set up immediately in the new API by
calling runConnections() on the client, and this blocks until either the
task it's running on is cancelled or beginGracefulShutdown is called.
Because of this, either we'd have to modify our API to have
VirtualMachineAgent implementations call some run() method, or we just
put runConnections in an internal task on Vminitd. This change uses the
latter approach as it's simpler.
- Updated dependencies to pick up latest protobuf and grpc-swift-2
fixes.
- ClientBootstrap.withConnectedSocket(fd).wait() registers the vsock fd
with epoll/kqueue immediately. vminitd sends its HTTP/2 SETTINGS frame
right away upon accepting the connection, so those bytes can arrive on
the fd — and be read by NIO — before the gRPC pipeline is installed.
With a bare pipeline, NIO has nowhere to send the bytes and discards
them.
- Buffer until ClientConnectionHandler is in the pipeline so it can
process the SETTINGS frame and fire .ready, then schedule delivery of
the buffered data with assumeIsolatedUnsafeUnchecked().execute.
- To help produce more accurate merged logs, defines a
`StderrLogHandler` in the vminitd Application.swift that writes
timestamps to the boot log with millisecond precision and format
identical to that of the log files created using the `--log-root` arg on
`container`.
- Updates hawkeye to latest version (v6.5.1).
- In vminitd, use the Server event loop group for the gRPC server.
Co-authored-by: Danny Canter <danny_canter@apple.com>
Today our CI builds all of the linux code we have with musl and libc to
ensure everything is silky smooth. We should have a way to do the same
locally. This adds a new macOS only goal that spins up a container
(requires `container` to be installed) that builds an image with our
deps (libarchive and compression libs) and then builds the project. It
supports supplying whatever libc (musl or glibc) to verify they both
work.
Related to https://github.com/apple/containerization/issues/606
To make sure the project (and many linux specific libraries) builds on
linux lets add a linux step to build for both musl and glibc. Eventually
this will run unit tests as well. This change needs a bit more libc
agnostic-ifying work to make sure things work for both libcs.
To be able to test vminitd/vmexec/linux specific packages on ci it'd be
a heck of a lot easier if `make` just worked. This should be the last
bit needed. The default goal currently compiles just fine after the
linux specific `make deps` is ran. Next in line would be adding decent
unit tests/actually getting ci setup for the linux bits.
Adds the vminitd version to the logs.
Switching to a local version of vminitd is non-trivial:
```
- .define("CZ_VERSION", to: "\"\(scVersion)\""),
+ .define("CZ_VERSION", to: "\"latest\""),
```
Having an additional confirmation of the used version in the logs is
vital.
Prior to this change, `make vmintid` failed with `which swift` equals to
`/usr/bin/swift`:
>
/Users/Dmitry/Apple/containerization/vminitd/.build/checkouts/swift-protobuf/Sources/SwiftProtobuf/AnyMessageStorage.swift:16:8:
error: compiled module was created by an older version of the compiler;
rebuild 'Foundation' and try again:
/Users/Dmitry/Library/org.swift.swiftpm/swift-sdks/swift-6.3-DEVELOPMENT-SNAPSHOT-2026-02-27-a_static-linux-0.1.0.artifactbundle/swift-6.3-DEVELOPMENT-SNAPSHOT-2026-02-27-a_static-linux-0.1.0/swift-linux-musl/musl-1.2.5.sdk/aarch64/usr/lib/swift_static/linux-static/Foundation.swiftmodule/aarch64-swift-linux-musl.swiftmodule
With an explicit path to Swift from Swiftly, `make vminitd` works both
with `which swift` equals to `~/.swiftly/bin/swift` or `/usr/bin/swift`.
- No real notable API changes. The largest change code-wise is in
Vminitd. The connection loop is set up immediately in the new API by
calling runConnections() on the client, and this blocks until either the
task it's running on is cancelled or beginGracefulShutdown is called.
Because of this, either we'd have to modify our API to have
VirtualMachineAgent implementations call some run() method, or we just
put runConnections in an internal task on Vminitd. This change uses the
latter approach as it's simpler.
- Updated dependencies to pick up latest protobuf and grpc-swift-2
fixes.
- ClientBootstrap.withConnectedSocket(fd).wait() registers the vsock fd
with epoll/kqueue immediately. vminitd sends its HTTP/2 SETTINGS frame
right away upon accepting the connection, so those bytes can arrive on
the fd — and be read by NIO — before the gRPC pipeline is installed.
With a bare pipeline, NIO has nowhere to send the bytes and discards
them.
- Buffer until ClientConnectionHandler is in the pipeline so it can
process the SETTINGS frame and fire .ready, then schedule delivery of
the buffered data with assumeIsolatedUnsafeUnchecked().execute.
- To help produce more accurate merged logs, defines a
`StderrLogHandler` in the vminitd Application.swift that writes
timestamps to the boot log with millisecond precision and format
identical to that of the log files created using the `--log-root` arg on
`container`.
- Updates hawkeye to latest version (v6.5.1).
---------
Co-authored-by: Danny Canter <danny_canter@apple.com>
Now that the static linux SDK we use has libarchive linked against it,
we can finally live our dream (/s) of supporting copying directories
in/out a little easier. This was.. kind of annoying. I think the very
simple route of writing archive to guest/host -> streaming over grpc is
simplest, but on the guest end we have a couple problems:
1. The VMs rootfs is read only today always, which is a good thing to me
and I don't want to change if we don't have to.
2. Writing the archive to the containers rootfs temporarily could work,
but it's a bit weird, and the user can make the containers rootfs
readonly which would screw that plan.
3. We could write it to /run or /tmp, but they're tmpfs and dealing with
the headache of the user possibly tarring an enormous dir is one I don't
want to care about.
So, that leaves us with the (truthfully better to me) approach of trying
to write the tar data directly to the host and skipping grpc which kinda
forces us to have a temp spot. Because of that, I made it such that we
pass a port number from host<->guest, and transfer the actual data
(either the single file or tarred dir contents) over the vsock port
instead. The stream is kinda clunky, but it just serves as a means to
exchange metadata and a "we're done" signifier.
Closes#221
This contains (in the static linux sdk but the swift version and the sdk
must match) libarchive support and mimalloc! This also (unrelated to the
sdk bump it seems) raises the amount of retries we do when dialing
vminitd. It seems CI on rare occasions recently has timed out on some
tests. We could also explore just lowering the concurrency on the
integration suite.
There are some workloads that benefit from having a "true" init process
that reaps zombies. This change implements a minimal init as part of
vminitd and exposes an API to be able to use this init process in our
containers. signals will be forwarded, any child procs will be reaped
and the exit code of the actual workload will be propagated. The
LinuxContainer/LinuxPod API is a very simple bool to ask to use this as
our init process, and the init simply spawns whatever command you want
as a child underneath this.
```
➜ ./bin/cctl run --kernel bin/kernel.arm64 --init
/ # ps aux
PID USER TIME COMMAND
1 root 0:00 /.cz-init -- /bin/sh
2 root 0:00 /bin/sh
3 root 0:00 ps aux
```
These two stats are import to calculate the following
- wss bytes (memory usage - inactive files)
- rss bytes (anonymous memory)
- available bytes (limit - wss bytes)
Just exposing these two in `SandboxContext.proto` as we already collect
them in `readMemoryStats()` in `Cgroup2Manager`
This adds a small flag named --log-level to be able to set the log level
of vminitd and the pause command. I imagine this won't be the last time
we'll have to add flags to vminitd so I went ahead and converted vminitd
to be a Argument Parser based binary as well.
- Adds a public method to wait for the relay to complete when both
directions close
- Improves error handling
- Moves `UnixSocketRelayManager` into a separate file
- Renames `SocketRelay` to `UnixSocketRelay`
- Adds logs at the info level after converting other logs to the debug
level previously
Michael Crosby