mesh-sdk/go/catalogue/settings.go

package catalogue

// Merge is how a file's content is combined with settings. A module names one per resource.
const (
	// MergeJSON treats the content as a JSON document and merges settings into it by key.
	MergeJSON = "json"
)

// Layer is one source of settings, in the order they are applied.
type Layer struct {
	// Where these came from, for saying which layer set a value.
	From   string
	Values map[string]any
	// Default marks the layer a module's own defaults make (novox/hq ADR 0262). Marked rather than
	// recognised by From, which is a node's name for a node's layer, and a node may be called anything.
	Default bool
	// Placement is the assignment's placement at this layer's scope — `places`, `accesses`, `networks`,
	// `endpoints`, `expose`, `reach`, `ports` — which the controller holds apart from settings (novox/hq
	// ADR 0348 clause 11, issues 651 and 736): read by their readers only, and never from Values. LayerOf
	// splits a layer as a person says it into the two.
	Placement map[string]any
}

// ServedSettings is every key a module's served values and its zone's name fill from its settings (`${setting:<key>}`
// in a top-level string, as Settle fills them), sorted: what every consumer of the module is told, wherever it runs,
// and so the one part of a module's config values on its node that a node composing a consumer elsewhere reads (issue
// 1126). None for a module that serves only literals.
func ServedSettings(m Manifest) []string {
	seen := map[string]bool{}
	note := func(v any) {
		if s, ok := v.(string); ok {
			for _, k := range settingsUsed(s) {
				seen[k] = true
			}
		}
	}
	for _, values := range m.Serves {
		for _, v := range values {
			note(v)
		}
	}
	if m.Zone != nil {
		note(m.Zone.Name)
	}
	return sortedKeys(seen)
}

// NetworksSetting is the settings key that keeps a found network for a taken container, on one
// adopted machine (novox/hq ADR 0163, rule 4):
//
//	{"networks": {"server": ["predecessor_default"]}}
//
// has the module's container `server` also join `predecessor_default` once taken, so a neighbour
// that resolves it by name on that network keeps resolving it. Migration scaffolding in the sense
// of ADR 0104: assigned only on an adopted machine, reported while it stands, removed when the
// neighbours are taken. Keyed by the container's resource id; the value is the networks it keeps.
const NetworksSetting = "networks"