DDI/agent/core/leases_test.go

// SPDX-License-Identifier: Apache-2.0

package core

import (
	"context"
	"errors"
	"fmt"
	"net/netip"
	"testing"
	"time"
)

func mustAddr(s string) netip.Addr { return netip.MustParseAddr(s) }

func lease(ip, mac string) Lease {
	return Lease{
		IP: mustAddr(ip), MAC: mac, Hostname: "host-" + ip, State: LeaseActive,
		Expires: time.Unix(1_800_000_000, 0), Updated: time.Unix(1_700_000_000, 0), SubnetID: 1,
	}
}

func TestDiffLeases(t *testing.T) {
	a, b, c := lease("10.0.0.1", "aa:00:00:00:00:01"), lease("10.0.0.2", "aa:00:00:00:00:02"), lease("10.0.0.3", "aa:00:00:00:00:03")
	changes, known := diffLeases(nil, []Lease{b, a, {}})
	if len(changes) != 2 || changes[0].IP != a.IP || changes[1].IP != b.IP || len(known) != 2 {
		t.Fatalf("initial changes = %+v", changes)
	}
	if changes, _ := diffLeases(known, []Lease{a, b}); len(changes) != 0 {
		t.Errorf("unchanged leases reported: %+v", changes)
	}
	b2 := b
	b2.Expires = b.Expires.Add(time.Hour)
	changes, next := diffLeases(known, []Lease{b2, c})
	if len(changes) != 3 {
		t.Fatalf("changes = %+v", changes)
	}
	if changes[0].IP != a.IP || changes[0].State != LeaseExpired {
		t.Errorf("disappeared lease = %+v", changes[0])
	}
	if !changes[1].Expires.Equal(b2.Expires) || changes[2].IP != c.IP {
		t.Errorf("changes = %+v", changes)
	}
	if len(next) != 2 {
		t.Errorf("next = %v", next)
	}
	// Equal instants in different locations are not a change.
	b3 := b2
	b3.Expires = b2.Expires.In(time.FixedZone("x", 3600))
	if changes, _ := diffLeases(next, []Lease{b3, c}); len(changes) != 0 {
		t.Errorf("time zone change reported: %+v", changes)
	}
}

func TestPollLeases(t *testing.T) {
	f := newFixture(t, KindDHCP)
	ctx := context.Background()
	tr := &leaseTracker{needFull: true}
	a, b := lease("10.0.0.1", "aa:00:00:00:00:01"), lease("10.0.0.2", "aa:00:00:00:00:02")
	f.role.setLeases([]Lease{a, b})

	f.agent.pollLeases(ctx, f.role, tr)
	batches := f.src.leaseBatches()
	if len(batches) != 1 || !batches[0].FullSync || batches[0].Sequence != 1 || len(batches[0].Leases) != 2 {
		t.Fatalf("batches = %+v", batches)
	}

	// No change: nothing is sent.
	f.agent.pollLeases(ctx, f.role, tr)
	if n := len(f.src.leaseBatches()); n != 1 {
		t.Fatalf("%d batches after an unchanged poll", n)
	}

	// b released, a gone, c new: one delta.
	b.State = LeaseReleased
	c := lease("10.0.0.3", "aa:00:00:00:00:03")
	f.role.setLeases([]Lease{b, c})
	f.agent.pollLeases(ctx, f.role, tr)
	batches = f.src.leaseBatches()
	if len(batches) != 2 {
		t.Fatalf("batches = %+v", batches)
	}
	d := batches[1]
	if d.FullSync || d.Sequence != 2 || len(d.Leases) != 3 || d.Leases[0].State != LeaseExpired || d.Leases[1].State != LeaseReleased {
		t.Fatalf("delta = %+v", d)
	}

	// A failed report forces a full snapshot next time.
	f.src.mu.Lock()
	f.src.leaseErr = errors.New("down")
	f.src.mu.Unlock()
	c.Hostname = "renamed"
	f.role.setLeases([]Lease{b, c})
	f.agent.pollLeases(ctx, f.role, tr)
	if !tr.needFull {
		t.Fatal("failure did not request a full snapshot")
	}
	f.src.mu.Lock()
	f.src.leaseErr = nil
	f.src.mu.Unlock()
	f.agent.pollLeases(ctx, f.role, tr)
	batches = f.src.leaseBatches()
	last := batches[len(batches)-1]
	if !last.FullSync || len(last.Leases) != 2 || last.Sequence != 4 {
		t.Fatalf("snapshot after failure = %+v", last)
	}

	// The sequence survives a restart.
	st, err := f.store.LoadState()
	if err != nil {
		t.Fatal(err)
	}
	if st.LeaseSequence != 4 {
		t.Errorf("persisted sequence = %d", st.LeaseSequence)
	}

	// The full sync interval triggers a snapshot.
	tr.lastFull = time.Now().Add(-2 * time.Hour)
	f.agent.pollLeases(ctx, f.role, tr)
	batches = f.src.leaseBatches()
	if last := batches[len(batches)-1]; !last.FullSync || last.Sequence != 5 {
		t.Errorf("periodic snapshot = %+v", last)
	}

	// Errors of the role and a busy role skip the round.
	f.role.mu.Lock()
	f.role.leasesErr = errors.New("socket gone")
	f.role.mu.Unlock()
	n := len(f.src.leaseBatches())
	tr.needFull = true
	f.agent.pollLeases(ctx, f.role, tr)
	f.role.mu.Lock()
	f.role.leasesErr = nil
	f.role.mu.Unlock()
	f.agent.roleMu.Lock()
	f.agent.pollLeases(ctx, f.role, tr)
	f.agent.roleMu.Unlock()
	if len(f.src.leaseBatches()) != n {
		t.Error("leases reported despite an error or a running apply")
	}
}

func TestPollLeasesEmptySnapshot(t *testing.T) {
	f := newFixture(t, KindDHCP)
	tr := &leaseTracker{needFull: true}
	f.agent.pollLeases(context.Background(), f.role, tr)
	b := f.src.leaseBatches()
	if len(b) != 1 || !b[0].FullSync || len(b[0].Leases) != 0 {
		t.Fatalf("batches = %+v", b)
	}
}

func TestLeaseBatching(t *testing.T) {
	f := newFixture(t, KindDHCP)
	var leases []Lease
	for i := 0; i < 2*maxLeasesPerBatch+1; i++ {
		ip := netip.AddrFrom4([4]byte{10, byte(i >> 16), byte(i >> 8), byte(i)})
		leases = append(leases, Lease{IP: ip, MAC: fmt.Sprintf("aa:00:00:%02x:%02x:%02x", byte(i>>16), byte(i>>8), byte(i)), State: LeaseActive})
	}
	f.role.setLeases(leases)
	f.agent.pollLeases(context.Background(), f.role, &leaseTracker{needFull: true})
	b := f.src.leaseBatches()
	if len(b) != 3 {
		t.Fatalf("%d batches", len(b))
	}
	if !b[0].FullSync || b[1].FullSync || b[2].FullSync {
		t.Errorf("full_sync flags = %v %v %v", b[0].FullSync, b[1].FullSync, b[2].FullSync)
	}
	if len(b[0].Leases) != maxLeasesPerBatch || len(b[2].Leases) != 1 || b[0].Sequence != 1 || b[2].Sequence != 3 {
		t.Errorf("batches: %d/%d/%d leases, sequences %d..%d", len(b[0].Leases), len(b[1].Leases), len(b[2].Leases), b[0].Sequence, b[2].Sequence)
	}
}

func TestLeaseLoopNotStartedForDNS(t *testing.T) {
	f := newFixture(t, KindDNS)
	role := dnsOnlyRole{f.role}
	a, err := NewAgent(KindDNS, f.agent.cfg, role, f.store, &Identity{AgentID: testAgentID, BundleKey: f.agent.bundleKey}, f.src, testLogger())
	if err != nil {
		t.Fatal(err)
	}
	if _, ok := a.role.(LeaseSource); ok {
		t.Fatal("DNS test role implements LeaseSource")
	}
	ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
	defer cancel()
	if err := a.Run(ctx); err != nil {
		t.Fatal(err)
	}
	if n := len(f.src.leaseBatches()); n != 0 {
		t.Errorf("%d lease batches from a DNS agent", n)
	}
}