A module may not declare an action: the link may not carry a command to
run, and that bound is what limits a compromised control plane to shapes
it cannot turn into arbitrary code (novox/hq ADR 0005). The host
enforces it, correctly and in the right place.
But a module's resources reach a machine over the link, so a manifest
carrying an action was accepted here, stored, resolved, planned and
pushed — and refused on the machine, in the host's log, with nothing
connecting it back to the manifest that caused it.
The rule held. It was just unusable, which is the same shape as the
network shape earlier today: the refusal was right, arrived far from its
cause, and nobody was reading the log.
The refusal names the rule and what to do instead, because "you may not"
with no alternative is where a module author stops.
Found while checking a claim I had written in the coverage document —
that a module cannot declare one. It could; it just could not deliver
it. The document is corrected.
Provisions were named after roles: provides "database", requires
"database". Nothing distinguished engines, so a module written against
PostgreSQL could be matched to a provider of SQL Server, resolve as
satisfied, deploy, and fail on its first query — with nothing
connecting that error back to a match made elsewhere by something that
believed it had done its job.
The failure is in the direction that hides. Refusing on ambiguity
exists precisely so this does not happen, and the generic name walked
around it: with one provider of each name nothing is ambiguous, so
nothing is asked.
How it got in: every resolver test had exactly one provider per name,
so no mismatch was expressible and none was caught. The fixtures agreed
with the design — the same fault as the imagined test output in
04-ISSUES/005, at the level of a name.
Refused rather than documented, because the old naming *was* the
documented convention. Providing database/db/sql/sql-database is now a
parse error naming what to write instead.
The rule is about coupling, not specificity everywhere: route and
resolver stay role-named, because a consumer genuinely cannot tell
which proxy answered. novox/hq ADR 0027.
jschoubben