FreeBSD guests downloaded their test binaries from vnet's
files.tailscale VIP at roughly 250 kB/s in CI, and transfers sometimes
wedged outright for many minutes, which is why TestSubnetRouterFreeBSD
timed out in about a third of its runs. Locally the same path moves
data at 100+ MB/s, so the problem was never CPU; it was TCP behavior
under two independent constraints, both diagnosed with a new
throughput harness (TestVnetPerfFreeBSDDownload), a VNET_TCP_DEBUG
endpoint sampler, and pcaps:
First, throughput is capped at receive-window/RTT. FreeBSD starts its
receive window at 64 kB and autoscales it in slow 16 kB steps, and on
an oversubscribed CI runner the effective RTT of the userspace vnet
data path reaches hundreds of milliseconds, giving almost exactly the
observed 250 kB/s. Fix: raise the FreeBSD guest's TCP buffer sysctls
in cloud-init before the downloads, and raise netstack's receive
buffer sizing for the reverse (upload) direction.
Second, the outright wedge: when netstack bursts more data than the
QEMU socket plus the guest's virtio RX ring can absorb, a wide swath
of segments is dropped downstream of vnet, and netstack's loss
recovery then crawls, retransmitting one or two segments per 200 ms
RTO for minutes at a time (a 33 MB transfer was observed taking 526
seconds against an otherwise idle receiver). Rather than depending on
recovery from mass loss, make the path effectively lossless by keeping
the maximum in-flight data (the 1 MB netstack send buffer) below the
downstream buffering: grow the guests' virtio RX rings from 256 to
1024 descriptors, enlarge the vnet-QEMU unix socket buffers, and grow
the netstack link endpoint queue from 512 to 4096 packets so a send
burst can't overflow it.
Also fixed along the way, found while chasing the above:
* pcapWriter fsync'd after every packet, serializing all traffic
behind disk writes when a test enables pcap; a pcap-enabled run
was capped at about 290 kB/s. Keep the per-packet Flush but drop
the per-packet fsync.
* Traffic originating from vnet's own netstack (control plane,
DERP, file servers) bypassed conditionedWrite, so SetLatency and
SetPacketLoss silently didn't apply to it.
* writeEthernetFrameToVM held one global mutex (and a shared
scratch buffer) across writes to all VMs, so one guest slow to
drain its socket stalled traffic to every VM on the server. The
write lock is now per-VM-connection.
TestSubnetRouterFreeBSD now passes locally in 31s (down from 4.5
minutes), still passes with the vnet simulating a 100 ms RTT
(downloads at 2-8 MB/s, previously 250-600 kB/s), and passes in 65s
with KVM disabled while pinned to two host CPUs, a harsher environment
than the CI runners. The benchmark test is opt-in via
--run-perf-tests (in addition to --run-vm-tests) so CI doesn't spend
a matrix job re-measuring it on every run. VMTEST_NO_KVM=1
forces TCG for reproducing slow-host behavior.
Fixestailscale/corp#44805
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: I1a7945a7e9c7d083b0ea2a3530eda0e9757dff18
Env.Start boots all VM nodes in parallel; each calls
createCloudInitISO -> ensureDebugSSHKey concurrently. When
/tmp/vmtest_key doesn't yet exist, the first goroutine creates it
with os.WriteFile, which opens with O_CREATE|O_TRUNC and briefly
leaves the file existing-but-empty between the open and the
subsequent write. A concurrent goroutine that hits that window
sees ReadFile succeed with zero bytes, then fails ssh.ParsePrivateKey
with "ssh: no key found", causing boot to fail with:
boot: creating cloud-init ISO: parse /tmp/vmtest_key: ssh: no key found
Observed in CI on TestSiteToSite (3 nodes). Wrap the function in
a package-level Mutex so the first caller fully writes the key
before any other caller reads it.
Updates #20228
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: Ie6399dcba0c397bb8041931d3de1c6063a11c568
This adds a fake vnet ACME service, TXT-backed SetDNS support, and a
VM test that fetches a certificate with tailscale cert, serves it with
tailscale serve, and verifies HTTPS from a second node.
This adds coverage motivated by #19915.
Updates #13038
Change-Id: Ie1e53409509337d81c8fbceb63f59f3dfbd48207
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The natlab vmtest suite (tstest/natlab/vmtest) and the integration nat
tests are gated behind --run-vm-tests because they need KVM and are
slow. Until now nothing in CI exercised them apart from a single
canary TestEasyEasy run on every PR.
Add .github/workflows/natlab-test.yml that runs the full opt-in suite
on demand (workflow_dispatch), on PRs labeled "natlab", and on main
every 12 hours via cron. The workflow has two phases:
- "prepare" builds the gokrazy VM image, downloads the Ubuntu and
FreeBSD cloud images once via the new natlabprep tool, and emits
a dynamic JSON matrix of every TestX function it finds in the two
opt-in packages.
- "test" is a per-test matrix that depends on prepare. Each matrix
job restores the shared caches and runs a single test, so adding
a new TestFoo is automatically picked up on the next run without
any workflow edits.
Rename the existing natlab-integrationtest.yml to natlab-basic.yml
since it's the small smoke variant (just TestEasyEasy on every PR);
the new natlab-test.yml is the bigger suite. The job inside is
renamed to EasyEasy for the same reason.
Move the macOS arm64 host check from vmtest.Env.Start into
vmtest.Env.AddNode so a test that adds a vmtest.MacOS node skips
immediately on a non-macOS host, and add an explicit
skipIfNotMacOSArm64 helper at the top of the two macOS-only tests
so the platform requirement is obvious to readers.
Quiet the takeAgentConnOne miss log in tstest/natlab/vnet by default
(it was the overwhelming majority of bytes in CI logs, with no signal
in healthy runs) and replace it with a periodic "still waiting" line
that only fires after 10s, so a truly stuck agent connection still
surfaces.
Updates #13038
Change-Id: I4582098d8865200fd5a73a9b696942319ccf3bf0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Add a vmtest that brings up two Ubuntu nodes, each behind its own
EasyNAT, joined to the tailnet. The sender pushes a small file via
"tailscale file cp" and the receiver fetches it via "tailscale file
get --wait", asserting that the filename and contents round-trip
unchanged.
To make Taildrop work in vmtest, three small pieces were needed:
The Linux/FreeBSD cloud-init now starts tailscaled with --statedir as
well as --state=mem:, so the daemon has a VarRoot to host Taildrop's
incoming-files directory. State itself remains in-memory (so nothing
persists across reboots); only the var-root scratch space is on disk.
vmtest.New grows a variadic EnvOption parameter and a SameTailnetUser
helper. When the option is passed, Start sets AllNodesSameUser=true
on the embedded testcontrol.Server. Cross-node Taildrop requires the
sender and receiver to share a Tailnet user (or have an explicit
PeerCapabilityFileSharingTarget granted between them, which we don't
plumb here), so TestTaildrop opts in. Existing tests don't.
cmd/tta gains /taildrop-send and /taildrop-recv handlers that wrap
"tailscale file cp" and "tailscale file get --wait", plus
Env.SendTaildropFile and Env.RecvTaildropFile helpers in vmtest that
drive them.
Updates #13038
Change-Id: I8f5f70f88106e6e2ee07780dd46fe00f8efcfdf1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
As a warm-up to making natlab support multiple operating systems,
start with an easy one (in that it's also Unixy and open source like
Linux) and add FreeBSD 15.0 as a VM OS option for the vmtest
integration test framework, and add TestSubnetRouterFreeBSD which
tests subnet routing through a FreeBSD VM (Gokrazy → FreeBSD →
Gokrazy).
Key changes:
- Add FreeBSD150 OSImage using the official FreeBSD 15.0
BASIC-CLOUDINIT cloud image (xz-compressed qcow2)
- Add GOOS()/IsFreeBSD() methods to OSImage for cross-compilation
and OS-specific behavior
- Handle xz-compressed image downloads in ensureImage
- Refactor compileBinaries into compileBinariesForOS to support
multiple GOOS targets (linux, freebsd), with binaries registered
at <goos>/<name> paths on the file server VIP
- Add FreeBSD-specific cloud-init (nuageinit) user-data generation:
string-form runcmd (nuageinit doesn't support YAML arrays),
fetch(1) instead of curl, FreeBSD sysctl names for IP forwarding,
mkdir /usr/local/bin, PATH setup for tta
- Skip network-config in cidata ISO for FreeBSD (DHCP via rc.conf)
Updates tailscale/tailscale#13038
Change-Id: Ibeb4f7d02659d5cd8e3a7c3a66ee7b1a92a0110d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Add tstest/natlab/vmtest, a high-level framework for running multi-VM
integration tests with mixed OS types (gokrazy + Ubuntu/Debian cloud
images) connected via natlab's vnet virtual network.
The vmtest package provides:
- Env type that orchestrates vnet, QEMU processes, and agent connections
- OS image support (Gokrazy, Ubuntu2404, Debian12) with download/cache
- QEMU launch per OS type (microvm for gokrazy, q35+KVM for cloud)
- Cloud-init seed ISO generation with network-config for multi-NIC
- Cross-compilation of test binaries for cloud VMs
- Debug SSH NIC on cloud VMs for interactive debugging
- Test helpers: ApproveRoutes, HTTPGet, TailscalePing, DumpStatus,
WaitForPeerRoute, SSHExec
TTA enhancements (cmd/tta):
- Parameterize /up (accept-routes, advertise-routes, snat-subnet-routes)
- Add /set, /start-webserver, /http-get endpoints
- /http-get uses local.Client.UserDial for Tailscale-routed requests
- Fix /ping for non-gokrazy systems
TestSubnetRouter exercises a 3-VM subnet router scenario:
client (gokrazy) → subnet-router (Ubuntu, dual-NIC) → backend (gokrazy)
Verifies HTTP access to the backend webserver through the Tailscale
subnet route. Passes in ~30 seconds.
Updates tailscale/tailscale#13038
Change-Id: I165b64af241d37f5f5870e796a52502fc56146fa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Mario MinardiandMario Minardi
Brad FitzpatrickandBrad Fitzpatrick