hal dnsmasq-app conversion, hq 08-connectivity. Converting the resolver from the module it
replaces made it forward what it cannot answer, which is what the predecessor's does, and
that found two things the controller did not say.
A resolver that forwards must not send a mesh name it does not know upstream: the
`node-zones` fact now carries `local=/<suffix>/` beside the wildcards, written here rather
than in the daemon's configuration because the suffix is the mesh's choice and this file is
the one place the mesh writes what it chose. The default lives in one helper now instead of
being spelled in two functions.
The predecessor points the container runtime's `dns` at the machine's own tunnel address —
a container cannot reach the machine's loopback. A module writing that key needs the
address, and `${machine:at}` is the machine's name; a runtime's resolver list cannot be a
name it would need that resolver to look up. So a module may say `${machine:address}`: what
`at` resolves to, read from the same names the hosts file and the wildcards are written
from, absent — and refused — off the network like `at` is.
The `mesh-resolver` and `resolver-data` constants go: nothing provided or consumed either,
the fact and `mesh-addressing` are the mechanism, and a requirement nothing provides is
refused at resolution.
Tests: the catalogue's dnsmasq, resolv-conf and resolved-split-dns manifests are parsed
and composed as a machine would receive them — fixed upstreams, no-resolv, 127.0.0.1, the
machines file, the runtime's key, the pair that decides what a machine asks refused on one
node; and on a real mesh the resolver's machines file is composed with a wildcard per
machine on the network and composed again without one that left, mirroring the hosts fact.
Review found the first pass aliased its answer under both ends of a mapping, which is
wrong wherever two mappings share a number: the alias lands on a key belonging to another
mapping, the later write wins, and the filter and the container then disagree — the very
fault this change exists to close. Two reproduced cases: a module publishing 8080:80 beside
9090:8080 had an explicit setting silently overwritten; a module publishing 4001:80 beside
4002:80 composed both containers onto one machine port, where before it was safely refused.
Now a mapping's answer is filed once, under the end the module names in its listens — the
number the plan, the filter, the openings, the guard and the consumer all ask for — and a
key that names two mappings is refused in the same words as a setting that does.
Also: the guard assertion in the end-to-end test failed open when the resource was absent;
the plan-mirroring helper now says it stands in only where the plan does not allocate, and
the assertions it feeds are narrowed to the port under test.
A module publishing `2222:22` — the machine's own ssh daemon holds 22, so
the module takes 2222 and says so in `listens` — could not be moved. The
setting was read against the last segment of each mapping alone, so the
number the module uses everywhere else was refused as a port it does not
publish, and the node's every push failed for as long as the setting was
stored. The one key that was accepted, the container's own port, was then
read only when the container's mapping was rewritten: the mapping moved
and the ports map, the filter, the adopted node's openings, its guard and
what a consumer is told all stayed on the number the software had left.
Either end of a mapping now names it, and a given port comes back under
both, so every reader finds the same number under the key it holds.
Ambiguity is refused where it is real — one number naming two different
mappings, or the two ends of one mapping given two different numbers.
${port:…} answered only inside a file's content, and the one place a module
routinely writes its own address is a container's `env` — where the literal is
wrong on every node whose assignment differs from the manifest's number, and
wrong again on a node given that port as a setting (ADR 0100). Nothing checked
it: the value is a string like any other, and it fails at runtime, on one node.
Filled by the control plane, like a bound value: a port is not secret, so there
is nothing for the host to be the only witness of and it learns no new field.
That is the line ADR 0086 draws — its objection is to a secret being in an
environment at all, not to who fills one in — so a port crosses it and a
credential still does not. Same guard as before: a port the module never said it
listens on is refused, now naming the container and the variable.
The env map is the catalogue's, shared by every node running the module, and the
resource around it is a shallow copy, so a filled value goes into a fresh map —
otherwise the first node composed writes its own port into the manifest and
every node after it is told that one.
Inert on the catalogue as it stands: ${port:…} is written in one other place in
it, a file. Renamed off _files, which this no longer is.
The builder carries a binding because at genesis nothing provides
`package-registry` to resolve one from; once the forge is a module the same
consumer is told what the forge serves. Nothing held the two to the same number,
so the catalogue could drift into dialling one port before the forge is assigned
and another after.
And `at` is now protected, for the reason it had to be: a setting that moves it
points the builder, and the registry password it sends, at a host somebody else
chose.
novox/hq 04-ISSUES/085
The package registry was the one foundation port not resolved from what its
module serves. Nothing in the controller had to change for it — `ports` on the
forge moves its container, what it serves and what consumers are told, and the
builder's carried binding is settable like any other mergeable file — but
nothing said so, which is how it came to be special in the first place.
Two tests over the catalogue's own manifests: the forge's port is given on a
node and reaches what it serves, and the builder's carried binding takes the
port from the node while keeping who the binding is with.
novox/hq 04-ISSUES/085
jschoubben