From e94163e475825bb642e218dd627436bbcf3303e7 Mon Sep 17 00:00:00 2001
From: Josh Black <raskchanky@gmail.com>
Date: Fri, 12 Apr 2024 09:28:16 -0700
Subject: [PATCH] add regeneration intent log (#26354)

---
 vault/activity_log.go      | 26 +++++++++++
 vault/activity_log_test.go | 96 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/vault/activity_log.go b/vault/activity_log.go
index 12a9496450..cdfa9d97d6 100644
--- a/vault/activity_log.go
+++ b/vault/activity_log.go
@@ -1175,6 +1175,32 @@ func (c *Core) setupActivityLogLocked(ctx context.Context, wg *sync.WaitGroup) e
 	return nil
 }
 
+func (a *ActivityLog) createRegenerationIntentLog(ctx context.Context, now time.Time) (*ActivityIntentLog, error) {
+	intentLog := &ActivityIntentLog{}
+	segments, err := a.availableLogs(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("error fetching available logs: %w", err)
+	}
+
+	for i, segment := range segments {
+		if timeutil.IsCurrentMonth(segment, now) {
+			continue
+		}
+
+		intentLog.PreviousMonth = segment.Unix()
+		if i > 0 {
+			intentLog.NextMonth = segments[i-1].Unix()
+			break
+		}
+	}
+
+	if intentLog.NextMonth == 0 || intentLog.PreviousMonth == 0 {
+		return nil, fmt.Errorf("insufficient data to create a regeneration intent log")
+	}
+
+	return intentLog, nil
+}
+
 // stopActivityLogLocked removes the ActivityLog from Core
 // and frees any resources.
 // this function should be called with activityLogLock
diff --git a/vault/activity_log_test.go b/vault/activity_log_test.go
index f1aae77a2d..644284c9bb 100644
--- a/vault/activity_log_test.go
+++ b/vault/activity_log_test.go
@@ -662,6 +662,102 @@ func TestActivityLog_availableLogs(t *testing.T) {
 	}
 }
 
+// TestActivityLog_createRegenerationIntentLog tests that we can correctly create a regeneration intent log given the segments in storage
+func TestActivityLog_createRegenerationIntentLog(t *testing.T) {
+	testCases := []struct {
+		name          string
+		times         []time.Time
+		expectedLog   *ActivityIntentLog
+		expectedError bool
+	}{
+		{
+			"no segments",
+			[]time.Time{},
+			nil,
+			true,
+		},
+		{
+			"one segment",
+			[]time.Time{
+				time.Date(2024, 4, 4, 10, 54, 12, 0, time.UTC),
+			},
+			nil,
+			true,
+		},
+		{
+			"most recent segment is 3 months ago",
+			[]time.Time{
+				time.Date(2024, 1, 4, 10, 54, 12, 0, time.UTC),
+				time.Date(2024, 1, 3, 10, 54, 12, 0, time.UTC),
+			},
+			&ActivityIntentLog{NextMonth: 1704365652, PreviousMonth: 1704279252},
+			false,
+		},
+		{
+			"lots of segments",
+			[]time.Time{
+				// two this month
+				time.Date(2024, 4, 4, 10, 54, 12, 0, time.UTC),
+				time.Date(2024, 4, 6, 10, 54, 12, 0, time.UTC),
+				// three last month
+				time.Date(2024, 3, 3, 10, 54, 12, 0, time.UTC),
+				time.Date(2024, 3, 6, 10, 54, 12, 0, time.UTC),
+				time.Date(2024, 3, 14, 10, 54, 12, 0, time.UTC),
+				// two the month before that
+				time.Date(2024, 2, 10, 10, 54, 12, 0, time.UTC),
+				time.Date(2024, 2, 17, 10, 54, 12, 0, time.UTC),
+			},
+			&ActivityIntentLog{NextMonth: 1712228052, PreviousMonth: 1710413652},
+			false,
+		},
+	}
+
+	core, _, _ := TestCoreUnsealed(t)
+	a := core.activityLog
+	now := time.Date(2024, 4, 10, 10, 54, 12, 0, time.UTC)
+	ctx := context.Background()
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			deletePaths := make([]string, 0)
+
+			// insert the times we're given
+			paths := make([]string, 0, len(tc.times))
+			for _, tm := range tc.times {
+				paths = append(paths, fmt.Sprintf("entity/%d/1", tm.Unix()))
+			}
+
+			for _, subPath := range paths {
+				fullPath := ActivityLogPrefix + subPath
+				WriteToStorage(t, core, fullPath, []byte("test"))
+				deletePaths = append(deletePaths, fullPath)
+			}
+
+			// regenerate the log
+			intentLog, err := a.createRegenerationIntentLog(context.Background(), now)
+			if tc.expectedError && err == nil {
+				t.Fatal("expected an error and got none")
+			}
+			if !tc.expectedError && err != nil {
+				t.Fatal(err)
+			}
+
+			// verify it's what we expect
+			if diff := deep.Equal(intentLog, tc.expectedLog); len(diff) != 0 {
+				t.Errorf("got=%v, expected=%v, diff=%v", intentLog, tc.expectedLog, diff)
+			}
+
+			// delete everything we wrote so the next test starts fresh
+			for _, p := range deletePaths {
+				err := core.barrier.Delete(ctx, p)
+				if err != nil {
+					t.Fatal(err)
+				}
+			}
+		})
+	}
+}
+
 // TestActivityLog_MultipleFragmentsAndSegments adds 4000 clients to a fragment
 // and saves it and reads it. The test then adds 4000 more clients and calls
 // receivedFragment with 200 more entities. The current segment is saved to