mesh-sdk/go/catalogue/seat_paths.go

package catalogue

import (
	"path"
	"strings"
)

// SeatPath is one path a seat's holder owns: absolute, literal, on the machine where the holder runs.
type SeatPath struct {
	Path string `json:"path"`
	// StepsBackFor is a node seat whose holder owns the path instead, on a machine where that seat is held
	// (novox/hq ADR 0287, ADR 0247): this seat's holder still declares the path, and its declaration is not
	// composed there. Only the mesh's own seats step back, each by a record.
	StepsBackFor string `json:"steps-back-for,omitempty"`
}

// declaredPaths is every machine path a module declares it owns: a resource's literal path, and a file
// the mesh renders for it outside the operator's home. An access is not here — reading is not owning.
//
// **Cleaned, because the machine writes the cleaned path**: /etc//hosts, /etc/./hosts, /etc/../etc/hosts and
// /etc/hosts/ are all /etc/hosts to it, and a seat's path is clean by its own rule, so a declaration compared
// as written would pass for a path nobody named.
func declaredPaths(m Manifest) map[string]bool {
	out := map[string]bool{}
	if m.OwnsPaths != nil {
		// Carried: what its manifest declares, never what runs of it (issue 1126, seed-8: f1-circuits, snake and txt-game
		// on ace owned their /var/lib paths on the node and none on the controller).
		for _, p := range m.OwnsPaths {
			out[p] = true
		}
		return out
	}
	for _, r := range m.Resources {
		if p, ok := r["path"].(string); ok && strings.HasPrefix(p, "/") {
			out[path.Clean(p)] = true
		}
	}
	for _, f := range m.Facts {
		if !f.Home && strings.HasPrefix(f.Path, "/") {
			out[path.Clean(f.Path)] = true
		}
	}
	return out
}

// missingPaths is each path a seat names that a module does not declare, in the seat's order.
func missingPaths(m Manifest, paths []SeatPath) []string {
	if len(paths) == 0 {
		return nil
	}
	has := declaredPaths(m)
	var missing []string
	for _, p := range paths {
		if !has[p.Path] {
			missing = append(missing, p.Path)
		}
	}
	return missing
}