mesh-sdk/go/catalogue/seat_paths_test.go

package catalogue

import (
	"strings"
	"testing"
)

// Defends novox/hq ADR 0287 (issue 412): a seat names the paths its holder owns, a claim without them is
// refused, and only a claimant declares a seat's path.

// The starting set, exactly: node-hostname names /etc/hosts and /etc/hostname, node-uplink the resolver
// file stepping back for node-resolver, node-resolver the resolver file, and every other seat names none.
func TestTheSeatsThatNamePathsAreTheStartingSet(t *testing.T) {
	want := map[string]string{
		"node-hostname": "/etc/hosts /etc/hostname",
		"node-uplink":   "/etc/resolv.conf>node-resolver",
		ResolverSeat:    "/etc/resolv.conf",
	}
	for _, s := range DefaultSeats() {
		var got []string
		for _, p := range s.Paths {
			if p.StepsBackFor != "" {
				got = append(got, p.Path+">"+p.StepsBackFor)
			} else {
				got = append(got, p.Path)
			}
		}
		if strings.Join(got, " ") != want[s.Name] {
			t.Errorf("%s names %v; ADR 0287 gives it %q", s.Name, got, want[s.Name])
		}
	}
}

// What the store's rows carry is never the paths: a row read back keeps the compiled ones.
func TestTheSeatPathsSurviveTheStoresRows(t *testing.T) {
	before := seats
	t.Cleanup(func() { seats = before })
	UseSeats([]Seat{{Name: "node-hostname", Scope: ScopeNode}})
	s, _ := SeatNamed("node-hostname")
	if len(s.Paths) != 2 {
		t.Fatalf("node-hostname read back from its row names %v", s.Paths)
	}
}

func hostnameSeat(t *testing.T) Seat {
	t.Helper()
	s, ok := SeatNamed("node-hostname")
	if !ok {
		t.Fatal("no node-hostname seat")
	}
	return s
}

func hostnameHolder(resources ...map[string]any) Manifest {
	return Manifest{Module: "names", Version: "1", Claims: []Claim{{Name: "node-hostname", Scope: ScopeNode,
		Serves: []string{"entries", "add", "remove"}}}, Resources: resources}
}

type writesHosts struct{}

func (writesHosts) Resources(string) ([]map[string]any, bool, error) {
	return []map[string]any{{"id": "hosts", "type": "file", "path": "/etc/hosts", "into": "block",
		"content": "10.42.0.1 anchor\n"}}, true, nil
}

// The controller is bound too: what it generates for a machine on a seat's path is refused at composition.
func TestAGeneratedResourceOnASeatsPathIsRefused(t *testing.T) {
	r := Resolution{Node: "workstation", Modules: []Manifest{
		{Module: "mesh-names", Computed: "mesh-names"},
	}}
	_, err := r.Declaration(Rendering{Generators: map[string]Generator{"mesh-names": writesHosts{}}})
	if err == nil {
		t.Fatal("a generated resource on /etc/hosts was composed")
	}
	for _, want := range []string{"mesh-names", "/etc/hosts", "node-hostname"} {
		if !strings.Contains(err.Error(), want) {
			t.Errorf("the refusal does not name %s: %v", want, err)
		}
	}
}

// Who owns a seat's path on a machine: the seat naming it and its holder there, with the stepping back
// applied — the resolver's holder where node-resolver is held, else the uplink's.
func TestPathOwnersApplyTheSteppingBack(t *testing.T) {
	held := []Held{
		{Claim: "node-uplink", Scope: ScopeNode, Node: "laptop", Module: "networkmanager"},
		{Claim: ResolverSeat, Scope: ScopeNode, Node: "laptop", Module: "systemd-resolved"},
		{Claim: "node-uplink", Scope: ScopeNode, Node: "server", Module: "systemd-networkd"},
		{Claim: "node-hostname", Scope: ScopeNode, Node: "server", Module: "hostname"},
	}
	var got []string
	for _, o := range PathOwners(Seats(), held) {
		got = append(got, o.Path+" "+o.Node+" "+o.Seat+" "+o.Module)
	}
	want := []string{
		"/etc/hostname server node-hostname hostname",
		"/etc/hosts server node-hostname hostname",
		"/etc/resolv.conf laptop node-resolver systemd-resolved",
		"/etc/resolv.conf server node-uplink systemd-networkd",
	}
	if strings.Join(got, "\n") != strings.Join(want, "\n") {
		t.Errorf("the owners are\n%s\nnot\n%s", strings.Join(got, "\n"), strings.Join(want, "\n"))
	}
}

// The stepping back comes from the seat, and is of a rendered file only: an uplink holder declaring the
// resolver file as a resource beside a node-resolver holder is two writers of one path, refused when the
// machine is resolved — never composed twice — as before the seat named its paths.
func TestAnUplinkDeclaringTheResolverFileAsAResourceIsRefusedBesideTheResolver(t *testing.T) {
	shelf := resolverShelf(t)
	uplink := shelf["systemd-networkd"]
	uplink.Facts = nil
	uplink.Resources = append(append([]map[string]any(nil), uplink.Resources...),
		map[string]any{"id": "resolvers", "type": "file", "path": ResolverFile, "content": "nameserver 10.42.0.1\n"})
	shelf["systemd-networkd"] = uplink
	shelf["local-resolver"] = localResolver()
	_, err := Resolve(shelf, []string{"dnsmasq", "systemd-networkd", "local-resolver"}, splitDNSLaptop(), World{})
	if err == nil || !strings.Contains(err.Error(), `both declare the path "/etc/resolv.conf"`) {
		t.Fatalf("an uplink declaring the resolver file as a resource beside the resolver was not refused: %v", err)
	}
	// Its rendered file steps back, by the seat's definition, and nothing else of it does.
	rendered := Manifest{Module: "uplink", Version: "1", Claims: []Claim{{Name: "node-uplink"}},
		Facts: map[string]RosterFile{"resolvers": {Path: "/etc//resolv.conf", Template: "x"},
			"other": {Path: "/etc/uplink.conf", Template: "x"}}}
	got := stepsBack(rendered, []Manifest{rendered, localResolver()})
	if len(got.Facts) != 1 || got.Facts["other"].Path == "" {
		t.Errorf("the uplink's holder renders %v beside the resolver", got.Facts)
	}
}