Two setup faults, each of which looked like the thing being tested failing.
The builder module was assigned without its artifact ever being built, so
nothing could start — and the build has to happen while the hand-started
builder is still alive. Same chicken-and-egg as the registry, resolved the same
way: the builder that exists builds the one that replaces it.
The firewall test's listeners were squeezed through three levels of shell
quoting and never started, so the test failed on its own setup — which reads
exactly like the firewall working.
Written and loaded are different things, and loaded and enforcing are different
again. The test opens two ports on a machine, declares one of them, and checks
from the other machine that the declared one answers and the undeclared one
does not — then removes the module and checks the port closes with nobody
editing a rule.
The base image gains nftables, read back through `nft --version` like the other
three: a machine that cannot load a rule set applies the mesh's filtering,
reports success and filters nothing, which is the exact fault the derivation
exists to remove.
Two earlier tests were asking for things that are not there. The lab's registry
drops tags when it stocks, so `registry:2` is not served and the mirror test
failed with "not found" — it now uses the pinned digest, which is what a
declaration carries anyway.
went
`exec` waited two minutes always. A build, or anything that waits on
another machine, needs longer — and a caller that cannot say so has to
split the work to fit, which is a test shaped by its harness rather than
by what it is testing.
The scenario also places a build machine when one is given, so anything
in it can ask the mesh to build something. Nothing else here would start
one.
And the mesh-runs-its-own-artifact-store test is not here. It needs a
fourth image so the module has a registry to mirror, and that is caught
behind 04-ISSUES/012 — left as a note saying where it went and why,
rather than silently deleted, because what it asserted is worth
asserting.
Broken with a package that does not exist, so the failure is real and
fixable. The mesh reports it failed; the resources that could be applied
were, because one broken thing no longer blocks the rest; `push --behind`
names that machine and not the one that is fine; the module is corrected;
and the machine recovers with nobody naming it.
And with nothing behind, it says so rather than doing nothing quietly.
Two properties the design claims and neither had been run.
A push to a machine that is switched off must not be lost — a machine is
disconnected as an ordinary situation, not an exception. The queue is
durable and the message persistent, which ought to be enough, but a lost
declaration is silent and "ought to be" is not a property. It waits: the
machine's host is stopped, the push happens, nothing changes on the
machine, and when it listens again it applies what it missed with no
second push and nobody saying anything.
Getting there found a real fault, now fixed in mesh-host and recorded as
04-ISSUES/011: the machine stopped at the first failing resource, so one
broken module blocked every module after it for ever. The evidence was
the broker's queues being EMPTY — the declaration had been delivered and
read.
And removal: two modules assigned, one unassigned, and the machine loses
exactly that one's file while keeping the other's — and keeps the store,
broker and control plane it raised from its own bundle, which the mesh
never declared and must never remove.
Two of my own traps recorded in the test, because both cost real time:
`pkill -f` matches the shell running it, which kills the connection
carrying the command and hangs the caller for ever; and a test that
depends on state another test left behind fails for a reason that has
nothing to do with what it claims.
The status path was demonstrated with inserted rows, which proves the
query and not the path. This sends a real machine something it will
genuinely fail at — a package that does not exist — and asks the mesh
afterwards.
A failure of the ordinary kind: the host tries, the package manager says
no, some of the declaration is applied and some is not. That is the
situation `status` exists to distinguish from a machine that refused
everything, and the test asserts the distinction survives the whole way:
the machine is listed as failed rather than refused, the failing resource
is named in the host's own words, and the machine that did as it was told
is not implicated.
The chain this closes: a repository exists, the mesh asks for it, a build
machine takes the work, publishes what it made, and the catalogue then
says what the module is, which commit it came from, and — after the
source moves — that it is behind.
Three assertions, against a real broker and registry, because what is
under test is four processes agreeing over a wire:
- the mesh asks, a machine builds, and the artifact is really in the
registry at the digest the manifest names
- a build that cannot succeed says why and records nothing. A failure
that is silent is indistinguishable from a builder that is not running
- the source moving makes the catalogue say "behind", and rebuilding
catches it up
git is now in the base image, with the same reasoning as docker and
wireguard-tools: a machine that builds modules clones them, and a sealed
scenario cannot install anything. Read back from `git --version` rather
than from the package manager — an installed package is not a
capability, and a build machine whose clone fails does so three minutes
into a scenario with the failure reported as a build problem rather than
a lab one.
Everything before this proved a part. This proves the parts meet, which
the project keeps saying cannot be checked any other way.
A bare machine applies the substrate bundle and becomes a mesh — store,
schemas, broker with a certificate it generated itself, control plane
serving. Both machines then join it with nothing but a token. A database
is declared on one and an application on the other, and after a push:
- both ends hold the SAME password, or nothing could authenticate
- it is mode 0600 on the machine that uses it
- it appears in neither machine's stored declaration, neither machine's
reported state, nor the control plane's database — so it was not
readable by the broker that carried it or the mesh that sent it
- the consumer is also told where its database is, by a name the mesh
wrote into that machine's hosts file
The bundle's image references are rewritten to the ones this scenario's
registry serves. A digest belongs to whatever registry serves it, so a
committed bundle names a registry that is not this one — rewriting is
what makes it applicable rather than a placeholder to tidy away.
Two faults found getting here, both fixed in mesh-host: `apply` could not
read a file the bundle could, and the token did not say what the mesh
calls the machine.
The mesh generates a password, seals it to the machine that must accept
it, and discards the plaintext — so it cannot tell PostgreSQL to start
accepting it. Something on that machine reads what the host wrote and
makes it true. Everything up to that step is proven elsewhere; this is
where a password either becomes a login or does not.
A scenario with one machine and a database, and six assertions: the
password works, running again reaches the same state and says nothing,
rotation makes the new one work and the old one stop, a departed consumer
loses its login, a role nobody here made is left alone, and a manifest
naming a credential that was never written is refused rather than
creating a login with no password.
Each was confirmed to fail — and only it to fail — with the behaviour
removed from the provisioner: only-creates breaks rotation, no-revoke
breaks revocation, revoking everything breaks the bystander role, and
ignoring a missing credential breaks the refusal.
Two faults in the test itself, both worth recording:
- it checked logins from inside the database's own container over
127.0.0.1, which PostgreSQL's default pg_hba trusts. No password was
ever verified. Demonstrated directly: over loopback a deliberately
wrong password still returns a row. Only the rotation assertion
noticed, because it is the one that requires a password to STOP
working — which is an argument for writing that assertion every time.
- the fix then read .NetworkSettings.IPAddress, which docker 29 no
longer populates. It templates to empty, psql falls back to a unix
socket that is not there, and every login looks impossible rather than
misconfigured.
'incus list' failed because this shell had no permission to reach the daemon,
incusOk returned null, and the caller wrote ?? "[]". So 'mesh-lab list'
printed 'no scenario instances standing' -- confidently, about a question it
had never managed to ask.
The comment on incusOk warns about exactly this, in those words: absence and
success made indistinguishable. Three of its own callers then did it. Two
listings and the live diagram, which would have drawn an empty scenario rather
than fail -- a picture that is confidently wrong, which is worse than none.
Anything enumerating what exists now goes through enumerate() and throws.
incusOk stays right where failure genuinely means no, like instanceExists,
and there is a test holding that line so this does not get over-corrected
until nothing can be asked at all.
Worth noting 'mesh-lab check' already diagnoses this precise cause, down to
'a session that predates it cannot see it'. The diagnosis existed; the
listing just never asked for it.
Comments naming records that no longer exist now point at the consolidated
record holding their reasoning -- the four lab records are 0016, a test defends
a decision is 0017.
Issue 009's resolution, proven manually end to end before any of it was
written.
A sealed machine pulled an image BY DIGEST from a registry on its own segment
and ran it; then the host applied all four shapes -- package, service with
boot, container from that digest, and an action inside it -- idempotently. That
is the first time the container shape has worked anywhere but a workstation,
and it was the shape blocking the whole substrate bootstrap.
The registry's digests are its own, not Docker Hub's, and that is correct
rather than a compromise: ADR 0046 requires a reference that is exact and
cannot move, and a digest this registry assigned is both. It is also not a
lab workaround -- 0048 names an OCI registry as substrate and 0046 says a first
node fetches "upstream, wherever the image ordinarily lives". This IS that
upstream, scenery in the same sense the transit router is the internet.
The base image now trusts the RFC 5737 and RFC 3849 documentation ranges as
plain-HTTP registries. Scoped to those rather than an address because they
never route on the real internet, so it cannot make a real machine trust a real
registry whatever it is copied onto.
Three faults found while verifying, two of them mine:
My probe script picked an interface with `ls /sys/class/net | head -1`, which
returns docker0 once a runtime exists -- so it addressed the wrong interface and
then, because that address overlapped the segment, broke routing on the machine
entirely. The lab itself is immune: it matches by MAC, for a related reason it
already recorded (bus-position naming on multi-homed machines).
And a test that proved nothing: I asserted `sha256:tooshort` is rejected, but
its letters fall outside a-f, so it failed the character class rather than the
length check. Replaced with hex of the wrong length, after which removing the
length check bites.
ADR 0046's open consequence: "the lab needs a way to place images, and the
machine it places them into needs a container runtime, which a sealed scenario
cannot install either."
The runtime half is done, and it is research 012's reframing applied literally
-- fetch at build time on a machine with a network, apply on a target that
needs nothing. `mesh-lab base build` launches a machine WITH a network,
installs a runtime, verifies it by asking the runtime rather than the package
manager, and publishes the result. Measured: ~30s to install, ~60s to publish,
~700MiB, paid once per lab rather than per scenario.
A scenario that places `runtime` or an image is then raised from that base
image, chosen rather than declared -- a scenario says what it needs, not which
image provides it. If the base does not exist it says so and how to build it.
Verified in a genuinely sealed machine (no route out, confirmed by ping):
package, service including the new `boot: enabled`, and action all applied,
were idempotent on a second run, and read back correctly. Those three had never
run anywhere but a workstation.
The image half is NOT done, and testing found why: a digest-pinned image cannot
be placed from an archive. `docker save alpine@sha256:...` produces an archive
with no repo tag, because a repo digest only exists for an image a registry
served -- so it loads dangling and a container declaring that digest reaches
for a registry the machine cannot see.
That collides with ADR 0046, which has the host REFUSE an unpinned image. Tag
refused by the host, digest unusable in the lab: there is currently no
declaration the lab can raise that exercises the container shape at all. Filed
as 04-ISSUES/009, whose resolution is a registry inside the scenario -- which is
what the real mesh does rather than a workaround for the lab.
Also fixed a weak check of my own, which is the same fault in miniature: the
load was tested with `includes("Loaded image")`, a prefix of both `Loaded
image:` and `Loaded image ID:`. So an unusable dangling load reported success
and the failure surfaced later as a container that would not start.
The lab raised an underlay and put nothing on it: correct, and useless, because
the thing it exists to test did not exist. Tier 0 now does, so `place: [host]`
works and a raised scenario finally contains something.
The refusal narrows rather than disappearing. A scenario placing a host and a
substrate is told which half is missing, by name — not that `place:` is
unsupported when half of it now works.
Placement reads back rather than assuming. A file arriving is not a host
working, so the binary is run before it is trusted to answer questions, and what
it reports is read from the machine (ADR 0035). The binary comes from an
explicit path, because the declaration design leaves where artifacts come from
open and a search would harden into the answer by accident.
The integration test that matters is the one asserting the host reports the
MACHINE and not the workstation that placed it. A raised VM and this workstation
differ in every capability — root versus uid 1000, a clean init versus a
degraded one, no docker versus docker, no wireguard versus wg0 — so a host
reporting the wrong machine is obvious here and invisible anywhere else.
And the placed host independently confirms ADR 0031: overlay absent on a freshly
raised machine. The underlay suite already asserted that by looking for
wireguard interfaces; this is a second witness rather than the same check twice.
Two tests failed the moment placement worked, which is what they were for. They
defended "there is nothing to place yet" while that was true; the decision
changed, so they change with it rather than being deleted.
Gate: 75 unit, 20 integration.
The suite next door raises one scenario and asks deep questions of it. This one
asks shallow questions of every scenario — the half that was missing, since both
faults found by hand lived in scenarios nothing ever built.
Adds bootstrap-single, the cheapest, and the loop that lets the list grow. Also
adds the second universal invariant: every address a scenario declared is one
the machine actually holds. A machine that came up bare looks identical to one
that came up correctly until something asks it.
Verified to bite rather than assumed: against a live instance, the real
declaration passes and a declaration claiming an address nothing holds fails
with 'anchor declared 192.0.2.99 on hosting but holds 192.0.2.10'.
Integration now runs with --test-concurrency=1. Two files raise real instances,
node --test runs files in parallel by default, and two concurrent runs of this
suite already produced a whole-suite failure once — every test red, from
resource contention rather than from any fault in the code.
Gate: 45.7s -> 60.2s.
The address collision was found by eye. This is the mechanical form of it: no
two machines hold one address on one segment.
Pure over already-collected facts, so the logic is tested without a hypervisor
— including the cases that would make it useless if got wrong: the same address
on DIFFERENT segments is normal and must not be reported, and one machine
holding an address twice is not two machines.
Asserted against whatever the integration suite has standing, read from the
hypervisor rather than from the declaration. The declaration is what was
accepted, and it was accepted.
Found by asking what gw-devices and gw-home actually were, in a picture that
finally made them easy to see side by side.
planRouters grouped on the exact address list, so `home` declaring a v4 and a v6
address and `devices` declaring only the v4 became two router containers — both
holding 198.51.100.7 on the same segment. The lab raised it without complaint.
Not theoretical. On the raised instance the transit router resolved that one
address to two different MACs across a cache flush:
198.51.100.7 -> 02:c9:16:70:23:29 (gw0, which HAS the :443 dnat)
198.51.100.7 -> 02:bd:75:0b:b0:75 (gw1, which has none)
So home-server's published port worked or did not depending on which container
answered ARP last — intermittent, and it would have presented as a flaky test
rather than as a broken scenario.
One public address is one box. Checked against the thing this models rather than
argued from the model: a bridged modem, a single gateway holding the public
address, one network behind it, and every port forward landing on one host at
that address. Two routers on one address is not a topology, it is a collision.
Gateways to the same segment sharing any address are now one router and their
address lists union, so a v6 address declared on only one of the segments it
serves is still carried. Where such declarations disagree on nat, forwardable or
mapping_ttl, validate refuses — one box cannot behave two ways.
the-ordinary-shape now raises 7 machines instead of 8, and gw0 holds the public
address on eth0 while serving home on eth1 and devices on eth2.
The drawings were confusing, and looking at them showed why: a single stack
ordered by depth put a private network far from the public one it sits behind,
so a gateway's link to the outside ran the full height of the picture through
three networks it had nothing to do with — and two such links overlapped, so
they read as one wire.
Now each public network is followed by everything behind it, depth first. Every
gateway is adjacent to the network it serves, every link is a short stub, and
"behind" is shown by INDENTATION rather than by a line to follow. Gaps are sized
to what they hold, so a gap with no gateway in it takes no room. Transit is not
on a boundary — it reaches every public network at once — so it is stated once
at the top instead of drawing a line to each.
Both sources now order by name rather than by the order the source yielded. The
hypervisor cannot know declaration order, and two pictures laid out differently
cannot be compared, which is the whole point of having both.
Fixed while testing: the gap size and the box placement each decided separately
which network a gateway sat above, and disagreed — reserving the gap above one
sibling while drawing the box above the other, which landed a gateway on top of
a machine in an unrelated network. Both now read one map.
Five new tests, run across every scenario: no link crosses a network it does not
touch, no box is drawn inside a network it is not on, a network behind another
is indented inside it, a public network is not split apart by another group, and
both sources lay the same topology out identically.
`mesh-lab diagram` renders a scenario as draw.io, from either source, through
one layout — so a difference between what was asked for and what exists is a
difference you can see.
The shape says what a resource is and is fixed per kind. The badges say what is
true about that particular one and come entirely from metadata: translation,
forwardability, mapping expiry, refuses-inbound, container-or-VM, running. The
interesting properties of a network are exactly the ones with no visual
consequence — a translated address looks identical to an untranslated one.
For the live picture to be a record rather than a restatement, raise now writes
down what it applied: a segment's kind, ranges and MTU on the link; a gateway's
translation, forwardability and expiry on the gateway; inbound: deny on the
machine. Every behavioural tag is written AFTER the thing works, never at
creation — a failed raise leaves wreckage standing on purpose, and a picture of
that wreckage must not badge translation the router never got.
The pairing earned itself immediately: drawn side by side, every virtual machine
held no addresses. A container's interface carries the device's name and a VM
names its own, so joining them by name silently dropped one whole class of
machine. Fixed by joining on MAC.
Also brings tests under the typecheck gate, which caught integration timeouts
being passed as a 4th argument and therefore ignored entirely.
Reviewed and the criticism was right: 1,072 of 2,128 lines untested, all of
it the half that touches the hypervisor, and no gate. The verification I had
done was real — pings across NAT, TTL counts, ruleset comparisons — and none
of it survived the terminal it ran in, which is 04-ISSUES/005 in miniature.
Ten integration tests against a real hypervisor, each named for what it
defends. ADR 0031: a raised machine carries no overlay, no wireguard, no
mesh config — a scenario that pre-built peering would certify its own work.
ADR 0032: exec is the only way in. ADR 0033: routers are containers while
machines are virtual machines. And the design's claims: raise waits for
usable, snapshots are whole-scenario, NAT hides a private address,
published reaches the machine at the gateway's address.
Mocking the hypervisor is forbidden, so they skip with a reason on a
machine that cannot raise scenarios rather than passing green having
checked nothing.
The suite earned itself on its first run. It found that a snapshot of a
running machine could miss a file written seconds earlier — not stale,
absent — because the write was still in the guest's page cache. That is
exactly the question the lifecycle design listed as open: does a scenario
snapshot need the machines stopped? It does not, but it does need them
flushed. snapshot now syncs every machine before capturing, and the design
records the answer.
The fix buys write-durability, not application-consistency: anything
mid-transaction is still captured mid-transaction, and that is now stated
rather than assumed.
npm run check is the gate — typecheck, 40 unit tests, 10 integration tests.
The full topology now raises: four machines, three routers, a transit
router, six segments, in 35 seconds. Everything the declaration model can
express except `place`, which is refused because the node host it would
place does not exist yet.
Transit was a real gap, not a bug. The design says public networks are
unrelated and routed to each other, never bridged — and I built the
segments and never built the thing that routes between them, so three
public networks were islands and nothing crossed. A transit router now
holds an interface on every public segment, forwarding and no translation:
the closest thing the lab has to the internet, deliberately dumb.
Proven rather than asserted, by ping TTL across the raised topology:
within one segment ttl=64 no hops
across two unrelated public networks ttl=62 gateway + transit
multicast between public networks 0 replies
A flat internet would have shown ttl=64 and answered multicast — which
would let a node discover a peer it could never reach in production, and
report success. That is the fault the as-is layer records the mesh already
hitting with multicast name resolution.
inbound: deny is implemented as a host firewall on the machine, read back
after applying. A declared refusal that silently did not load leaves the
machine wide open, which looks exactly like a machine that is working.
Established and related traffic is accepted, so a defended machine can
still dial out rather than being a disconnected one.
Verified by running, all of it:
home -> devices (policy allow) reachable
devices -> home (policy deny) blocked
behind unforwardable NAT -> out reachable
in -> behind unforwardable NAT unreachable
inbound: deny, dialling out reachable
reaching a machine that denies inbound refused
The two routers differ exactly as declared: the forwardable one carries the
policy rule and no inbound drop, the unforwardable one carries `ct state
new drop` and no DNAT.
A gateway is the one implicit machine in a declaration — a scenario says a
segment sits behind one and never names the thing that serves it. This
materialises it.
A router is a container, not a virtual machine, because it is scenery
rather than something under test (hq ADR 0033). Verified before building
that a plain unprivileged container can do all of it: ip_forward and ipv6
forwarding settable, nftables masquerade accepted, and the conntrack
timeouts mapping_ttl depends on both writable. No privileged mode.
Verified by running, on a machine behind a household gateway reached from
one on a routable address:
home-server -> anchor 0% loss, through masquerade
anchor -> 192.168.1.135 (private, direct) unreachable
anchor -> 192.0.2.50:8080 (the GATEWAY) HTTP 200
The last line is the published-but-behind-NAT case research 004 says only
exists in production. It is now a 32-second scenario on a workstation.
Segments sharing a gateway declaration share ONE router — that is what a
VLAN-capable router is, and two routers sharing an external address would
not work anyway.
mapping_ttl is read back after setting rather than assumed. Those sysctls
are not on every kernel, and a scenario that declared an expiring mapping
and silently got a permanent one would be exactly the fault being built
against.
Four bugs found by running it, three of them the same fault — a failure
made invisible.
The router had no route to a package repository, by design, so installing
nftables at raise time could not work. The image is now built once with
temporary connectivity and cached; every scenario after that needs no
network. That failure was hidden behind `|| true`, which is why it took a
raise to find.
The builder then failed on DNS: exec works before a container has an
address, and I had treated usable as ready. It now waits for the thing
actually needed.
The stock Alpine image ships `auto eth0 / inet dhcp` and its boot-time
networking service flushed the static address the scenario set — on eth0
only, so the outside interface came up bare while inside ones were fine.
The image build now neutralises it: a router reconfiguring itself from an
image default is the lab overriding the declaration. `ip addr add … || true`
had hidden this too, and is now `ip addr replace` with no swallow.
And routers were orphaned by destroy, holding their networks open so
destroy reported removing zero segments. They now carry the same machine
tag as everything else, so one query finds an instance's resources.
A declaration goes in and a disposable mesh comes out. Verified on a
workstation, not asserted: two machines raised and addressed in 14.6s,
snapshot 0.28s, restore-to-usable 11.6s, both families pinging with no
loss, and the workstation with no route into any of it.
The declaration layer implements the model in full — three positions a
machine can be in, keyed on forwardability; gateways carrying the address
the world sees them as; both address families; multi-homing; MTU;
inter-segment policy. It is validated hard because the failures it prevents
are silent: a private range on a public segment produces no error, the mesh
simply never forms. Public segments are refused unless they use RFC 5737 or
RFC 3849 space, and a range wider than the reserved block is refused too.
33 tests, all offline.
The runtime implements less than the model, and refuses the difference.
A scenario declaring gateways, published ports, policy, inbound deny or
place is rejected at raise with every gap named. Raising it would produce a
mesh that silently lacks what it declared, which is the fault this lab
exists to catch — 04-ISSUES/003, where a firewall key is declared in five
manifests and read by no code.
Three bugs found by review and by running it, all of one family:
The readiness check truthiness-tested incusOk's return. `exec … true`
succeeds with EMPTY output, so every machine reported unreachable while
incus exec on it worked perfectly. succeeds() now exists so the mistake is
not available, and network delete had the same bug — it counted zero
segments removed while removing them.
list() split instance from machine on the last dash, so a machine called
home-server absorbed half the instance id and destroy found nothing.
Resources are now found by the metadata they carry, never by name.
restore reported success in 0.79s while the machine's agent was still
starting, so the next command failed. Both raise and restore now wait for
usable and say how long that took — reporting the earlier number is
transport reported as effect, which is the fault the lab is being built to
find.
Two incus behaviours worth recording. Its CLI reads a YAML definition from
stdin when stdin is not a terminal, so a spawned command hangs until the
timeout kills it and arrives with empty stderr — a failure with no
explanation, on a command that works when typed. And it assigns a MAC at
runtime without recording it in device config, so MACs are derived and set
explicitly, which the guest needs anyway: it names interfaces by bus
position, and matching by name configures the wrong one on a multi-homed
machine.
No build step; Node strips the types. The lifecycle has no unit tests
because a fake hypervisor would assert that the fake behaves as expected,
which is the shape of test this project exists to stop shipping.
jschoubben