Steward 0.1.0 (in development): a DHCPv4 server with a web UI, API and CLI

Subnets served per interface, pools, reservations, options at three
levels, leases in SQLite saved before the ACK, ping and decline conflict
checks, validated changes with history and undo, users and tokens, an
audit log, a Kea importer, a sandboxed systemd unit and Debian packages.
Tested with real udhcpc and dhcpcd clients in Docker (scripts/e2e.sh).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/engine/engine_test.go

@@ -0,0 +1,140 @@
+package engine
+
+import (
+	"context"
+	"net/netip"
+	"strings"
+	"testing"
+
+	"steward/internal/auth"
+	"steward/internal/model"
+	"steward/internal/store"
+)
+
+func newEngine(t *testing.T) *Engine {
+	t.Helper()
+	st, err := store.Open(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	e, err := New(context.Background(), st, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return e
+}
+
+var admin = &auth.Principal{User: &model.User{ID: 1, Username: "admin", Admin: true}, Method: "session"}
+
+func addOffice(t *testing.T, e *Engine) int64 {
+	t.Helper()
+	var id int64
+	res, err := e.Apply(context.Background(), admin, "", Options{Via: "cli"}, func(st *model.State, newID func() int64) error {
+		p, _ := model.ParsePool("10.0.10.100-10.0.10.199")
+		id = newID()
+		st.Subnets = append(st.Subnets, &model.Subnet{ID: id, Name: "office", Interface: "eth0", Prefix: netip.MustParsePrefix("10.0.10.0/24"),
+			Pools: []model.Pool{p}, Options: []model.OptionValue{{Code: 6, Value: "10.0.10.2,10.0.10.3"}}})
+		return nil
+	})
+	if err != nil || !res.Applied || res.HistoryID == 0 {
+		t.Fatalf("apply: %+v %v", res, err)
+	}
+	return id
+}
+
+func TestApplyNormalizesAndRecords(t *testing.T) {
+	e := newEngine(t)
+	id := addOffice(t, e)
+	s := e.State().SubnetByID(id)
+	if s.Options[0].Value != "10.0.10.2, 10.0.10.3" || s.Options[0].Name != "domain-name-servers" {
+		t.Errorf("options not normalized: %+v", s.Options)
+	}
+	h, _ := e.Store().ListHistory(context.Background(), 10, 0)
+	if len(h) != 1 || h[0].Description != "create subnet office (10.0.10.0/24)" || h[0].Via != "cli" || h[0].Username != "admin" {
+		t.Errorf("history %+v", h[0])
+	}
+	// Nothing changed: nothing recorded.
+	res, err := e.Apply(context.Background(), admin, "", Options{}, func(st *model.State, _ func() int64) error { return nil })
+	if err != nil || res.Applied || len(res.Changes) != 0 {
+		t.Errorf("empty change: %+v %v", res, err)
+	}
+	// Reloading from the database gives the same state.
+	e2, err := New(context.Background(), e.Store(), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d := Diff(e.State(), e2.State()); len(d) != 0 {
+		t.Errorf("reloaded state differs: %+v", d)
+	}
+}
+
+func TestValidationRefuses(t *testing.T) {
+	e := newEngine(t)
+	addOffice(t, e)
+	_, err := e.Apply(context.Background(), admin, "", Options{}, func(st *model.State, newID func() int64) error {
+		st.Subnets = append(st.Subnets, &model.Subnet{ID: newID(), Interface: "eth1", Prefix: netip.MustParsePrefix("10.0.0.0/16")})
+		return nil
+	})
+	ee, ok := AsError(err)
+	if !ok || ee.Kind != KindValidation || !strings.Contains(ee.Message, "overlaps subnet office") {
+		t.Fatalf("got %v", err)
+	}
+	if len(e.State().Subnets) != 1 {
+		t.Error("refused change was kept")
+	}
+}
+
+func TestDryRun(t *testing.T) {
+	e := newEngine(t)
+	res, err := e.Apply(context.Background(), admin, "", Options{DryRun: true}, func(st *model.State, newID func() int64) error {
+		st.Subnets = append(st.Subnets, &model.Subnet{ID: newID(), Interface: "eth0", Prefix: netip.MustParsePrefix("10.0.10.0/24")})
+		return nil
+	})
+	if err != nil || res.Applied || len(res.Changes) != 1 || len(res.Warnings) != 1 || res.Warnings[0].Code != "subnet_no_pools" {
+		t.Fatalf("dry run: %+v %v", res, err)
+	}
+	if len(e.State().Subnets) != 0 {
+		t.Error("dry run changed the state")
+	}
+}
+
+func TestRevert(t *testing.T) {
+	ctx := context.Background()
+	e := newEngine(t)
+	var got *model.State
+	e.OnChange = func(st *model.State) { got = st }
+	id := addOffice(t, e)
+	res, err := e.Apply(ctx, admin, "longer leases", Options{}, func(st *model.State, _ func() int64) error {
+		st.SubnetByID(id).LeaseTime = 86400
+		return nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got == nil || got.SubnetByID(id).LeaseTime != 86400 {
+		t.Error("OnChange didn't get the new state")
+	}
+	// Undoing the creation conflicts: the subnet changed since.
+	if _, err := e.Revert(ctx, admin, 1, Options{}); err == nil || !strings.Contains(err.Error(), "has changed since entry 1") {
+		t.Fatalf("revert of an older entry: %v", err)
+	}
+	if _, err := e.Revert(ctx, admin, res.HistoryID, Options{}); err != nil {
+		t.Fatal(err)
+	}
+	if e.State().SubnetByID(id).LeaseTime != 0 {
+		t.Error("revert didn't restore the lease time")
+	}
+	if _, err := e.Revert(ctx, admin, res.HistoryID, Options{}); err == nil || !strings.Contains(err.Error(), "already undone") {
+		t.Errorf("second revert: %v", err)
+	}
+	if _, err := e.Revert(ctx, admin, 1, Options{}); err != nil {
+		t.Fatalf("revert of the creation: %v", err)
+	}
+	if len(e.State().Subnets) != 0 {
+		t.Error("subnet still there")
+	}
+	h, _ := e.Store().GetHistory(ctx, 1)
+	if h.RevertedBy == 0 {
+		t.Error("entry 1 not marked undone")
+	}
+}