Files
mesh-controller/internal/catalogue/chosen.go
T
jschoubben cf84117638 A pin names the module as well as the node; a node that answers twice is refused
A provider is a (node, module) pair (design 23), and the pin — the one way a
consumer names its provider — named only the node. Two modules on one node
can both answer a provision (public-acme and step-ca both offer acme-ca on
novox), and then the resolver, given a pin naming that node, took the last
provider listed: a coin flip. The same ambiguity beside the consumer was
settled by a map walk — random per plan — which is how novox's own
route-proxy got its issuer (novox/hq #258).

- `pin <node> <provision> <from-node> <module>`: both halves, always. The
  console gains `pin` and `unpin`. The provider may be on the consumer's own
  node, since two modules beside it can both answer.
- The resolver refuses ambiguity instead of picking, across machines and
  beside the consumer alike, naming every candidate as node/module and the
  form of the pin that settles it. A plain capability that grants nothing
  and serves nothing (three shells beside an editor) is not a choice to put
  to anybody and stays as it was.
- provision_pin gains a nullable module (0050); records made before are
  completed where the node they name answers once, and left for a person
  where it answers twice (0051).
- The provider of something already satisfied is looked for among what was
  assigned, not only what the walk has reached — a consumer reached before
  the provider beside it no longer loses its binding.
- The start-time check that every declared verb is runnable samples each
  verb's required arguments from its schema instead of three guessed keys.

Live consequence: a node that has two providers of one bound provision
assigned (novox: acme-ca) resolves only once pinned —
`pin novox acme-ca novox public-acme`.
2026-10-01 17:23:31 +02:00

101 lines
2.7 KiB
Go

package catalogue
import (
"sort"
)
// Chosen is the provider somebody named for a provision: the module, and the node it runs on. Both,
// always (novox/hq #258) — a provision comes from a module, and the same module on two machines is
// two answers, so neither half alone says which. Module is empty only on a record made before this
// was asked, and such a record is honoured exactly as long as it is unambiguous.
type Chosen struct {
Node string
Module string
}
func (c Chosen) String() string {
if c.Module == "" {
return c.Node
}
return c.Node + "/" + c.Module
}
// matches is whether this provider is the one chosen.
func (c Chosen) matches(p Provider) bool {
return p.Node == c.Node && (c.Module == "" || p.Module == c.Module)
}
// among is every offered provider the choice names — one, when the choice is whole.
func (c Chosen) among(where []Provider) []Provider {
var out []Provider
for _, p := range where {
if c.matches(p) {
out = append(out, p)
}
}
return out
}
// nameOf is how a refusal names a provider: the node and the module on it.
func nameOf(p Provider) string {
return Chosen{Node: p.Node, Module: p.Module}.String()
}
// providerNames is every provider named, sorted, for a refusal to list.
func providerNames(where []Provider) []string {
out := make([]string, 0, len(where))
for _, p := range where {
out = append(out, nameOf(p))
}
sort.Strings(out)
return out
}
// providersHere is which modules in this node's own set offer a provision, sorted.
func providersHere(catalogue map[string]Manifest, here func(string) bool, want string) []string {
var out []string
for name, m := range catalogue {
if !here(name) {
continue
}
for _, o := range m.Offers() {
if o == want {
out = append(out, name)
break
}
}
}
sort.Strings(out)
return out
}
// servedByOne is what one provider beside the consumer says a consumer needs to know, or nothing.
//
// Serving is *whether* a need is created at all when the provider is on this same machine (novox/hq
// 04-ISSUES/038's sibling): a need never created is a binding the consumer never gets. The manifest
// alone answers that; the values are settled later, with the node's settings.
func servedByOne(m Manifest, want string) map[string]any {
if _, ok := m.Serves[want]; ok {
return ServedOn(m, want, nil)
}
return nil
}
// sharedByOne is the own secret that provider names as its credential (ADR 0158), or "" when it
// gives each consumer its own.
func sharedByOne(m Manifest, want string) string {
if own, shared := m.SharedCredentialOf(want); shared {
return own
}
return ""
}
func oneOf(list []string, s string) bool {
for _, x := range list {
if x == s {
return true
}
}
return false
}