Scoping the image tag was never sufficient on its own. Every build read one
unscoped directory in the working tree, into which each run copies the
binaries it just built, so two concurrent runs raced on the contents of the
context as well as on the name of the result — and a run could produce a
correctly-per-run-tagged image built from the other run's binaries.
The run now copies the context's tracked files into its own directory,
installs its binaries there, and builds from it, exporting the path so every
other consumer follows. Deliberately not carried over: a previous run's
binaries, since inheriting them is the failure this prevents. The path is
absolute because compose resolves a relative build context against the
compose file's own directory rather than the working directory, which was
measured rather than assumed.
The chaos entry script gated the whole simulation on a binary in the shared
directory by literal path, so it moves in this same commit: left behind, it
would have failed on a clean checkout and, worse on a host with leftovers,
passed while reading a binary that was not the one under test.
Teardown removes the directory on red runs as well as green, since it holds
only reproducible content and is never the evidence of a failure. The
worker's SIGKILL runs no trap, so the cleanup script also sweeps contexts
left by a preempted run, and the ignore rule keeps a concurrent run from
showing up as untracked working-tree noise.
The isolation loop and the failure-log dump both built container names
without the run suffix, so under a suffixed run they addressed containers
that do not exist.
The consequence was worse than the visible failure. Two of the three
checks in that loop assert a ping FAILS, and a ping into a non-existent
container fails for the wrong reason - so both passed vacuously, and the
security assertion the loop exists for was silently a no-op. Only the
third check, which expects a ping to succeed, noticed anything was wrong.
Add a guard that fails loudly when the container is absent, so a future
naming slip cannot quietly turn these back into no-ops rather than
surfacing as one confusing failure among two false passes.
These sites were missed because the suite passes when run by hand: with no
suffix set the unsuffixed names are correct, and the defect only appears
under the automation that sets one. Verified this time with the suffix
set, which is the condition that matters: 18 of 18, container names
resolving to real containers.
Making the sidecar network name unique per run exposed a latent problem
rather than causing a new one. With a fixed name, compose found any
existing network and reused it, which quietly masked the fact that the
address range was hardcoded. With a unique name there is nothing to
reuse, so the range is requested every time and the run fails outright if
anything already holds it.
Claim the range instead of assuming it. The suite now tries to create its
network on a candidate range and, if the daemon reports an overlap, moves
to the next candidate. The daemon's own address pool becomes the arbiter,
so two concurrent runs cannot land on the same range at all - as opposed
to a range derived from the run identifier, which only makes a collision
unlikely, and a collision is the precise failure being avoided.
The node addresses are derived from whichever range is claimed rather than
written alongside it, including the gateway address the isolation check
probes. Moved to a range that nothing in the tree claims and that sits
outside the daemon's default pool.
Only an overlap is worth advancing on. Any other creation failure is real
and is reported with the daemon's own message, rather than being retried
sixty-four times and buried - a lesson from a failure elsewhere in the
harness this week that was undiagnosable because its error output was
discarded.
All three nodes now attach to the pre-created network as external, so
teardown removes it explicitly.
Verified: three concurrent claims take three distinct ranges; a
non-overlap error fails fast rather than looping; the suite passes 18/18;
and the claimed gateway address is confirmed pingable when not firewalled,
so the isolation assertions still mean something.
Two runs on one host destroyed each other's containers, producing
mid-test "No such container" failures that look like real defects. The
automated builder runs a full local CI on the same box every few minutes,
so the machine is contended almost always and this has red-ed both a hand
run and an automated gate.
Two independent causes are fixed here. Container names were hardcoded, and
docker names are global rather than scoped by compose project, so two runs
collided on the same name; every name now takes an optional suffix that
the harness sets from the run id. And the cleanup sweep matched a label
shared by every run, so one run's teardown force-removed another's
containers; resources now also carry a per-run label and the sweep can be
narrowed to it.
A third hazard turned up that was not in the original report: the sidecar
suite passes explicit compose project names, which override the run-scoped
project and put it outside the shared prefix entirely. Its project names,
network, and derived container references are now scoped too.
Both are default-off. With the suffix unset, names render exactly as they
do today and a bare compose invocation is unchanged, which is what keeps
the hosted CI and the documentation correct. A cleanup run with no run id
still reaps everything, which is what a manual "clear the box" wants.
The literal-name sweep was not sufficient: six scripts build container
names dynamically from node labels, and two suites create their own
containers outside compose. Those are handled at their construction sites.
Verified: syntax check on all modified scripts; compose validation on
every modified file with the suffix both set and unset; and a synthetic
two-run reproduction that shows the old cleanup destroying a bystander run
and the new one leaving it alone.
Known gap: subnets are still hardcoded, so two concurrent full runs will
still collide on address-pool overlap. That fix reaches into topology
configs, chaos scenarios, diagrams and production source, so it is left
for its own change rather than half-done here.
The sidecar chain test intends node-a to be a standalone root ("node-a: no
outbound peers"), but started node-a without clearing FIPS_PEER_*, so it
inherited the external peer default from testing/sidecar/.env (a real public
mesh node, test-us01.fips.network) and auto-connected to the live mesh. The
whole a-b-c chain then attached under an external root, inflating tree depth and
breaking test isolation; this also produced spurious multi-hop failures.
Set FIPS_PEER_NPUB/FIPS_PEER_ADDR empty for node-a, matching how node-b and
node-c already get explicit inline peers, so the suite is hermetic regardless of
the .env default. Validated against the unmodified .env: node-a comes up with a
single link to node-b, no external attachment, multi-hop passes 18/18.
Add wait_until_connected to the shared convergence helpers: it polls a
suite's own pairwise pings (the signal it actually asserts on), returns
as soon as every pair is reachable, extends its deadline while the
reachable-pair count is still climbing, and gives up only when progress
stalls.
Use it in the rekey, static-mesh, and sidecar suites in place of the
fixed wall-clock baseline timeout and the blind sleep, which timed out
under concurrent CI load while the mesh was still converging.
Tailscale-style sidecar pattern: a FIPS container provides mesh
networking, and a companion app container shares its network namespace
via network_mode: service:fips.
Security model:
- iptables enforces strict isolation — the app container can only
communicate over the FIPS mesh (fd::/8 via fips0)
- No IPv4 access: eth0 restricted to FIPS UDP transport (port 2121)
- No IPv6 on eth0: ip6tables blocks all eth0 IPv6 traffic
- Only fips0 and loopback are reachable from the app container
The sidecar accepts peer configuration via environment variables
(FIPS_NSEC, FIPS_PEER_NPUB, FIPS_PEER_ADDR), so it can be pointed
at any FIPS node without config file generation.
Files:
- testing/sidecar/: Dockerfile, Dockerfile.app, docker-compose.yml,
entrypoint.sh, .env, resolv.conf, scripts/build.sh
- testing/sidecar/README.md: security model, quick-start, architecture,
DNS resolution, troubleshooting, production considerations
- testing/sidecar/scripts/test-sidecar.sh: 3-node chain integration
test verifying link establishment, multi-hop connectivity, and
network isolation on each app container
- .github/workflows/ci.yml: sidecar integration test matrix entry
Johnathan Corgan