Switch from the envd /init endpoint pushing host time via syscall to
chronyd reading the KVM PTP hardware clock (/dev/ptp0) continuously.
This fixes clock drift between init calls and handles snapshot resume
gracefully.
Changes:
- Add clocksource=kvm-clock kernel boot arg
- Start chronyd in wrenn-init.sh before tini (PHC /dev/ptp0, makestep 1.0 -1)
- Remove clock_settime logic from envd SetData and shouldSetSystemTime
- Remove client.Init() clock sync calls from sandbox manager (3 sites)
- Remove Init() method from envdclient (no longer needed)
- Simplify rootfs scripts: socat/chrony now come from apt in the container
image, only envd/wrenn-init/tini are injected by build scripts
- Use tini as PID 1 in wrenn-init.sh so zombie processes are reaped
and signals are forwarded correctly to envd
- Set standard PATH in wrenn-init.sh so child processes spawned by envd
can find common binaries (fixes "nice: ls command not found")
- Add envdclient.Init() to POST /init on envd after every boot/resume,
syncing the guest clock via unix.ClockSettime — critical after snapshot
resume where the guest clock is frozen
- Run Init in a background goroutine so it doesn't block the CreateSandbox
RPC response; a slow Init (vCPU busy with envd startup) was causing the
RPC context to be canceled before the response reached the control plane
- Update rootfs-from-container.sh and update-debug-rootfs.sh to inject
tini into the rootfs, checking the container image and host first,
downloading from GitHub releases as fallback
Add resolv.conf to wrenn-init so guests can resolve DNS, and fix the
host MASQUERADE rule to match vpeerIP (the actual source after namespace
SNAT) instead of hostIP.
Implement the host agent as a Connect RPC server that orchestrates
sandbox creation, destruction, pause/resume, and command execution.
Includes sandbox manager with TTL-based reaper, network slot allocator,
rootfs cloning, hostagent proto definition with generated stubs, and
test/debug scripts. Fix Firecracker process lifetime bug where VM was
tied to HTTP request context instead of background context.
Implements Phase 1: boot a Firecracker microVM, execute a command inside
it via envd, and get the output back. Uses raw Firecracker HTTP API via
Unix socket (not the Go SDK) for full control over the VM lifecycle.
- internal/vm: VM manager with create/pause/resume/destroy, Firecracker
HTTP client, process launcher with unshare + ip netns exec isolation
- internal/network: per-sandbox network namespace with veth pair, TAP
device, NAT rules, and IP forwarding
- internal/envdclient: Connect RPC client for envd process/filesystem
services with health check retry
- cmd/host-agent: demo binary that boots a VM, runs "echo hello", prints
output, and cleans up
- proto/envd: canonical proto files with buf + protoc-gen-connect-go
code generation
- images/wrenn-init.sh: minimal PID 1 init script for guest VMs
- CLAUDE.md: updated architecture to reflect TAP networking (not vsock)
and Firecracker HTTP API (not Go SDK)
