Cache a pre-booted macOS VM snapshot on disk so subsequent test runs
restore from the snapshot instead of cold-booting. The snapshot is keyed
by the Tart base image digest and a code version constant
(macOSSnapshotCodeVersion); bumping either invalidates the cache.
Snapshot preparation (one-time):
- Boot the Tart base image with a NAT NIC (--nat-nic flag)
- Wait for SSH, compile and install cmd/tta as a LaunchDaemon
- TTA polls the host via AF_VSOCK for an IP assignment; during prep
the host replies "wait"
- Disconnect NIC, save VM state via SIGINT
Test fast path (cached, ~7s to agent connected):
- APFS clone the snapshot, write test-specific config.json
- Launch Host.app with --disconnected-nic --attach-network --assign-ip
- VZ restores from SaveFile.vzvmsave (~5s with 4GB RAM)
- TTA's vsock poll gets the IP config, sets static IP via ifconfig
(bypasses DHCP entirely), switches driver addr to the IP directly
(bypasses DNS), and resets the dial context so the reverse-dial
reconnects immediately
- TTA agent connects to test driver within ~2s of IP assignment
Key optimizations:
- 4GB RAM instead of 8GB: halves SaveFile.vzvmsave (1.4GB vs 2.4GB),
halves restore time (5.5s vs 11s)
- AF_VSOCK IP assignment: bypasses macOS DHCP (~5-7s saved)
- Direct IP dial: bypasses DNS resolution for test-driver.tailscale
- Dial context reset: cancels stale in-flight dials from snapshot
- Kill instead of SIGINT for test VM cleanup (no state save needed)
- Parallel VM launches
Also:
- Add TestDriverIPv4/TestDriverPort constants to vnet
- Add --nat-nic and --assign-ip flags to Host.app
- Fix SIGINT handler: retain DispatchSource globally, use dispatchMain()
- Add vsock listener (port 51011) to Host.app for IP config protocol
- Add disconnectNetwork() to VMController for clean snapshot state
- Fix Makefile: set -o pipefail so xcodebuild failures aren't swallowed
Updates #13038
Change-Id: Icbab73b57af7df3ae96136fb49cda2536310f31b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Multi-NIC support:
- Add nodeNIC type and node.extraNICs for secondary network interfaces
- Add netForMAC/macForNet to route packets to the correct network by MAC
- Update initFromConfig to allocate a MAC + LAN IP per network
- Fix handleEthernetFrameFromVM, ServeUnixConn to use netForMAC
- Fix MACOfIP, writeEth, WriteUDPPacketNoNAT, gVisor write path, and
createARPResponse to use macForNet (return the MAC actually on that
network, not the node's primary MAC)
- Fix createDHCPResponse for multi-NIC (correct client IP and subnet)
- Add nodeNICMac for secondary NIC MAC generation
- Add Node accessors: NumNICs, NICMac, Networks, LanIP
DHCP fixes:
- Include LeaseTime, SubnetMask, Router, DNS in DHCP Offer (not just
Ack). systemd-networkd requires these to accept an Offer.
- Fix DHCP response source IP: use gateway IP instead of echoing
the request's destination (which was 255.255.255.255 for discovers)
New VIPs:
- cloud-init.tailscale: serves per-node cloud-init meta-data, user-data,
and network-config for VMs booting with nocloud datasource
- files.tailscale: serves binary files (tta, tailscale, tailscaled)
registered via RegisterFile for cloud VM provisioning
- Add ControlServer() accessor for test control server
This is necessary for a three-VM natlab subnet router
integration test, coming later.
Updates #13038
Change-Id: I59f9f356bae9b5509c117265237983972dfdd5af
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This file was never truly necessary and has never actually been used in
the history of Tailscale's open source releases.
A Brief History of AUTHORS files
---
The AUTHORS file was a pattern developed at Google, originally for
Chromium, then adopted by Go and a bunch of other projects. The problem
was that Chromium originally had a copyright line only recognizing
Google as the copyright holder. Because Google (and most open source
projects) do not require copyright assignemnt for contributions, each
contributor maintains their copyright. Some large corporate contributors
then tried to add their own name to the copyright line in the LICENSE
file or in file headers. This quickly becomes unwieldy, and puts a
tremendous burden on anyone building on top of Chromium, since the
license requires that they keep all copyright lines intact.
The compromise was to create an AUTHORS file that would list all of the
copyright holders. The LICENSE file and source file headers would then
include that list by reference, listing the copyright holder as "The
Chromium Authors".
This also become cumbersome to simply keep the file up to date with a
high rate of new contributors. Plus it's not always obvious who the
copyright holder is. Sometimes it is the individual making the
contribution, but many times it may be their employer. There is no way
for the proejct maintainer to know.
Eventually, Google changed their policy to no longer recommend trying to
keep the AUTHORS file up to date proactively, and instead to only add to
it when requested: https://opensource.google/docs/releasing/authors.
They are also clear that:
> Adding contributors to the AUTHORS file is entirely within the
> project's discretion and has no implications for copyright ownership.
It was primarily added to appease a small number of large contributors
that insisted that they be recognized as copyright holders (which was
entirely their right to do). But it's not truly necessary, and not even
the most accurate way of identifying contributors and/or copyright
holders.
In practice, we've never added anyone to our AUTHORS file. It only lists
Tailscale, so it's not really serving any purpose. It also causes
confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header
in other open source repos which don't actually have an AUTHORS file, so
it's ambiguous what that means.
Instead, we just acknowledge that the contributors to Tailscale (whoever
they are) are copyright holders for their individual contributions. We
also have the benefit of using the DCO (developercertificate.org) which
provides some additional certification of their right to make the
contribution.
The source file changes were purely mechanical with:
git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g'
Updates #cleanup
Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>
All the magic service names with virtual IPs will need IPv6 variants.
Pull this out in prep.
Updates #13038
Change-Id: I53b5eebd0679f9fa43dc0674805049258c83a0de
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Brad Fitzpatrick
Will Norris
Joe Tsai