Converge openings through the firewall an adopted node was found with, and retire it only when the node converges (hq ADR 0100)

internal/declaration/declaration.go

@@ -78,6 +78,12 @@ const (
 	// cadence. Tools, hooks and event consumers are not separate modes: they are loaded by a tool
 	// host, which is itself a process that stays up.
 	TypeProcess Type = "process"
+
+	// TypeOpening is a port the mesh needs reachable on an adopted node, converged through the
+	// firewall found there in that firewall's own terms (novox/hq ADR 0100). A state, not a
+	// command: the host adds the rule it marks as the mesh's when it is missing, and removes only
+	// what it marked — which is what lets it travel over the link.
+	TypeOpening Type = "opening"
 )
 
 // Resource is one thing that should be true of the machine.
@@ -603,6 +609,74 @@ func (s *Service) validate(where string, _ bool) []string {
 	return problems
 }
 
+// Opening is a port reachable on an adopted node, from where, and on which path.
+//
+// **From** is everywhere or mesh — the private network, by its interface. **Path** is incoming,
+// for something listening on the machine, or forwarded, for a published container port: the found
+// firewall sees a published port after the runtime has translated it, so a forwarded opening names
+// the container's own port in To as well as the machine's in Port.
+type Opening struct {
+	ID       string `json:"id"`
+	Type     Type   `json:"type"`
+	Port     int    `json:"port"`
+	Protocol string `json:"protocol"`
+	From     string `json:"from"`
+	Path     string `json:"path"`
+	To       int    `json:"to,omitempty"`
+}
+
+// Where an opening admits from, and the path it is on.
+const (
+	FromEverywhere = "everywhere"
+	FromMesh       = "mesh"
+	PathIncoming   = "incoming"
+	PathForwarded  = "forwarded"
+)
+
+func (o *Opening) Identity() string { return o.ID }
+func (o *Opening) Kind() Type       { return TypeOpening }
+
+func (o *Opening) Target() string {
+	if o.Path == PathForwarded {
+		return fmt.Sprintf("%s/%d forwarded to %d from %s", o.Protocol, o.Port, o.To, o.From)
+	}
+	return fmt.Sprintf("%s/%d %s from %s", o.Protocol, o.Port, o.Path, o.From)
+}
+
+func (o *Opening) validate(where string, _ bool) []string {
+	var problems []string
+	if o.Port < 1 || o.Port > 65535 {
+		problems = append(problems, fmt.Sprintf("%s: an opening's port is 1-65535, not %d", where, o.Port))
+	}
+	if o.Protocol != "tcp" && o.Protocol != "udp" {
+		problems = append(problems, fmt.Sprintf("%s: an opening is tcp or udp, not %q", where, o.Protocol))
+	}
+	if o.From != FromEverywhere && o.From != FromMesh {
+		problems = append(problems, fmt.Sprintf(
+			"%s: an opening is from %q or %q, not %q", where, FromEverywhere, FromMesh, o.From))
+	}
+	switch o.Path {
+	case PathIncoming:
+		if o.To != 0 {
+			problems = append(problems, where+
+				": an incoming opening names no container port; only a forwarded one does")
+		}
+	case PathForwarded:
+		if o.To < 1 || o.To > 65535 {
+			problems = append(problems, where+
+				": a forwarded opening names the container's port it reaches, as to, 1-65535")
+		}
+	default:
+		problems = append(problems, fmt.Sprintf(
+			"%s: an opening's path is %q or %q, not %q", where, PathIncoming, PathForwarded, o.Path))
+	}
+	if !strings.HasPrefix(o.ID, AdoptionPrefix) {
+		problems = append(problems, fmt.Sprintf(
+			"%s: an opening is the mesh's own, so its id starts %q", where, AdoptionPrefix))
+	}
+	return problems
+}
+
 // Package is a package that should be present.
 //
 // Present is the whole of what it asserts, never a version: version is the package manager's
@@ -810,6 +884,8 @@ func newOf(t Type) Resource {
 		return &Access{}
 	case TypeProcess:
 		return &Process{}
+	case TypeOpening:
+		return &Opening{}
 	}
 	return nil
 }
@@ -818,7 +894,7 @@ func newOf(t Type) Resource {
 func Vocabulary() []Type {
 	return []Type{
 		TypeAccess, TypeAction, TypeArchive, TypeContainer, TypeDirectory, TypeFile,
-		TypeNetwork, TypePackage, TypeProcess, TypeService, TypeUser,
+		TypeNetwork, TypeOpening, TypePackage, TypeProcess, TypeService, TypeUser,
 	}
 }
 
@@ -1051,6 +1127,18 @@ func parse(raw []byte, allowActions bool) (*Declaration, error) {
 		d.Resources = append(d.Resources, resource)
 	}
 	problems = append(problems, checkAdoption(env.Adoption, d.Resources, allowActions)...)
+	if env.Adoption == nil {
+		for _, r := range d.Resources {
+			if r.Kind() == TypeOpening {
+				// On a converged node the mesh's own filter admits what is declared, and the
+				// found firewall is retired; an opening there would be a rule in a firewall the
+				// mesh has disabled (novox/hq ADR 0100).
+				problems = append(problems, fmt.Sprintf(
+					"resource %q: an opening is for an adopted node, and this declaration does not "+
+						"say the node is adopted", r.Identity()))
+			}
+		}
+	}
 
 	if len(problems) > 0 {
 		return nil, &RefusalError{Problems: problems}