mesh-controller/internal/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])
		}
	}
}

// The compiled set keeps the rules: node seats only, absolute and literal, one seat per path without
// stepping back, and a stepping back that cannot cycle.
func TestTheCompiledSeatPathsKeepTheRules(t *testing.T) {
	if p := SeatPathProblems(DefaultSeats()); len(p) != 0 {
		t.Fatalf("the compiled set breaks ADR 0287: %v", p)
	}
	for _, c := range []struct {
		why  string
		set  []Seat
		want string
	}{
		{"a mesh seat naming a path", []Seat{{Name: "mesh-x", Scope: ScopeMesh, Paths: []SeatPath{{Path: "/etc/x"}}}},
			"only a node seat names paths"},
		{"a placeholder", []Seat{{Name: "node-x", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/${setting:x}"}}}},
			"placeholder"},
		{"a relative path", []Seat{{Name: "node-x", Scope: ScopeNode, Paths: []SeatPath{{Path: "etc/x"}}}},
			"not a clean absolute path"},
		{"two owners", []Seat{
			{Name: "node-a", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/x"}}},
			{Name: "node-b", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/x"}}}}, "no two seats name one path"},
		{"a cycle", []Seat{
			{Name: "node-a", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/x", StepsBackFor: "node-b"}}},
			{Name: "node-b", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/x", StepsBackFor: "node-a"}}}},
			"does not own that path itself"},
		{"stepping back for nobody", []Seat{
			{Name: "node-a", Scope: ScopeNode, Paths: []SeatPath{{Path: "/etc/x", StepsBackFor: "node-z"}}}},
			"not a node seat"},
	} {
		if got := strings.Join(SeatPathProblems(c.set), "; "); !strings.Contains(got, c.want) {
			t.Errorf("%s: %q does not say %q", c.why, got, c.want)
		}
	}
}

// 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}
}

// A holder declares every path its seat names, as a resource or as a file the mesh renders for it, or
// CanHold refuses it naming the seat and each missing path — the judgement registration and handover share.
func TestAClaimWithoutTheSeatsPathsIsRefused(t *testing.T) {
	seat := hostnameSeat(t)
	hosts := map[string]any{"id": "hosts", "type": "file", "path": "/etc/hosts", "content": "x"}
	name := map[string]any{"id": "name", "type": "file", "path": "/etc/hostname", "content": "x"}

	if err := CanHold(hostnameHolder(hosts, name), seat); err != nil {
		t.Errorf("a holder declaring both paths as resources was refused: %v", err)
	}
	rendered := hostnameHolder(hosts)
	rendered.Facts = map[string]RosterFile{"name": {Path: "/etc/hostname", Template: "{{.Node}}\n"}}
	if err := CanHold(rendered, seat); err != nil {
		t.Errorf("a holder declaring a path as a file the mesh renders was refused: %v", err)
	}
	err := CanHold(hostnameHolder(), seat)
	if err == nil {
		t.Fatal("a holder declaring neither path was accepted")
	}
	for _, want := range []string{"node-hostname", "/etc/hosts", "/etc/hostname", "ADR 0287"} {
		if !strings.Contains(err.Error(), want) {
			t.Errorf("the refusal does not name %s: %v", want, err)
		}
	}
	// A file under the operator's home is placed per account: it is not the machine's path.
	home := hostnameHolder(hosts)
	home.Facts = map[string]RosterFile{"name": {Path: "/etc/hostname", Home: true, Template: "x"}}
	if err := CanHold(home, seat); err == nil {
		t.Error("a file in the operator's home counted as the machine's /etc/hostname")
	}
	// At registration, the same refusal.
	if got := strings.Join(CatalogueProblems(Shelf{"names": hostnameHolder(hosts)}), "; "); !strings.Contains(got,
		"does not declare /etc/hostname") {
		t.Errorf("registration let a holder without /etc/hostname through: %q", got)
	}
}

// Only a claimant declares a seat's path: a module claiming no seat that names /etc/hosts and declaring
// it is refused at registration naming the seat; the uplink's holder and the resolver's both declaring
// the resolver file are each a claimant of a seat naming it. Reading a seat's path is access, and allowed.
func TestOnlyAClaimantDeclaresASeatsPath(t *testing.T) {
	stranger := Manifest{Module: "stranger", Version: "1", Resources: []map[string]any{
		{"id": "hosts", "type": "file", "path": "/etc/hosts", "into": "block", "content": "10.0.0.1 x\n"}}}
	got := strings.Join(CatalogueProblems(Shelf{"stranger": stranger}), "; ")
	if !strings.Contains(got, `stranger declares the path "/etc/hosts", which the seat node-hostname names`) {
		t.Errorf("a module declaring /etc/hosts without claiming node-hostname was not refused: %q", got)
	}
	reader := Manifest{Module: "reader", Version: "1", Accesses: []Access{{ID: "hosts", Path: "/etc/hosts"}}}
	if got := CatalogueProblems(Shelf{"reader": reader}); len(got) != 0 {
		t.Errorf("reading /etc/hosts was refused: %v", got)
	}
	uplink := Manifest{Module: "uplink", Version: "1", Claims: []Claim{{Name: "node-uplink", Scope: ScopeNode}},
		Facts: map[string]RosterFile{"resolvers": {Path: ResolverFile, Template: "nameserver 10.42.0.1\n"}}}
	resolver := localResolver()
	resolver.Claims[0].Serves = []string{"routes", "route", "unroute"}
	if got := CatalogueProblems(Shelf{"uplink": uplink, resolver.Module: resolver}); len(got) != 0 {
		t.Errorf("the uplink's holder and the resolver's declaring the resolver file were refused: %v", got)
	}
}

// A module's own seat names paths under the same rules: a node seat only, literal, and none another seat
// names — the second declaration loses. Its holder declares them, as a mesh seat's does.
func TestAModulesOwnSeatNamesPathsUnderTheSameRules(t *testing.T) {
	meshScoped := Manifest{Module: "a", Version: "1", DefinesSeats: []SeatDeclaration{
		{Name: "a-seat", Paths: []string{"/etc/a"}}}}
	if got := strings.Join(declaredSeatProblems(meshScoped), "; "); !strings.Contains(got, "only a node seat names paths") {
		t.Errorf("a module's mesh seat naming a path was accepted: %q", got)
	}
	placeholder := Manifest{Module: "a", Version: "1", DefinesSeats: []SeatDeclaration{
		{Name: "a-seat", Scope: ScopeNode, Paths: []string{"${dir:state}/a"}}}}
	if got := strings.Join(declaredSeatProblems(placeholder), "; "); !strings.Contains(got, "placeholder") {
		t.Errorf("a module's seat naming a path with a placeholder was accepted: %q", got)
	}

	taken := Manifest{Module: "b", Version: "1", DefinesSeats: []SeatDeclaration{
		{Name: "b-seat", Scope: ScopeNode, Paths: []string{"/etc/hosts"}}}}
	if got := strings.Join(CatalogueProblems(Shelf{"b": taken}), "; "); !strings.Contains(got,
		`b declares the seat b-seat naming the path "/etc/hosts", which node-hostname already names`) {
		t.Errorf("a module's seat naming /etc/hosts was accepted: %q", got)
	}

	own := Manifest{Module: "c", Version: "1",
		DefinesSeats: []SeatDeclaration{{Name: "c-seat", Scope: ScopeNode, Paths: []string{"/etc/c.conf"}}},
		Claims:       []Claim{{Name: "c-seat", Scope: ScopeNode}}}
	if got := strings.Join(CatalogueProblems(Shelf{"c": own}), "; "); !strings.Contains(got,
		"c claims c-seat but does not declare /etc/c.conf") {
		t.Errorf("a holder of a module's seat without its path was accepted: %q", got)
	}
	own.Resources = []map[string]any{{"id": "conf", "type": "file", "path": "/etc/c.conf", "content": "x"}}
	if got := CatalogueProblems(Shelf{"c": own}); len(got) != 0 {
		t.Errorf("a holder declaring its own seat's path was refused: %v", got)
	}
	other := Manifest{Module: "d", Version: "1", Resources: []map[string]any{
		{"id": "conf", "type": "file", "path": "/etc/c.conf", "content": "x"}}}
	if got := strings.Join(CatalogueProblems(Shelf{"c": own, "d": other}), "; "); !strings.Contains(got,
		`d declares the path "/etc/c.conf", which the seat c-seat names`) {
		t.Errorf("a module not claiming c-seat declared its path: %q", got)
	}
}

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: an uplink holder declaring the resolver file as a resource rather
// than a rendered file steps back too, and keeps everything else.
func TestTheUplinkStepsBackByTheSeatsDefinition(t *testing.T) {
	uplink := Manifest{Module: "uplink", Version: "1", Claims: []Claim{{Name: "node-uplink"}},
		Resources: []map[string]any{
			{"id": "resolvers", "type": "file", "path": ResolverFile, "content": "nameserver 10.42.0.1\n"},
			{"id": "conf", "type": "file", "path": "/etc/uplink.conf", "content": "x"}}}
	got := stepsBack(uplink, []Manifest{uplink, localResolver()})
	if len(got.Resources) != 1 || got.Resources[0]["id"] != "conf" {
		t.Errorf("the uplink's holder composes %v beside the resolver", got.Resources)
	}
	if p := checkResources([]Manifest{uplink, localResolver()}); len(p) != 0 {
		t.Errorf("the uplink's holder and the resolver's were refused together: %v", p)
	}
}

// The catalogue as it is passes: no holder of a seat naming a path is missing one, and nobody else
// declares one.
func TestTheCataloguePassesTheSeatPathRules(t *testing.T) {
	shelf := Shelf{}
	for _, m := range theCatalogue(t) {
		shelf[m.Module] = m
	}
	for _, p := range CatalogueProblems(shelf) {
		if strings.Contains(p, "ADR 0287") {
			t.Errorf("the catalogue breaks ADR 0287: %s", p)
		}
	}
}