feat: automated daily SQLite database backups with retention

New DatabaseBackupHostedService + SqliteDatabaseBackupRunner: - daily VACUUM INTO snapshot to <Data:Root>/backups (safe with WAL) - catch-up backup at startup when none exists from the last 24h - retention pruning (Backups:RetainCount, default 14) - warns and stays idle on MySQL/MariaDB where external backups apply Production previously had no automated database backup on Linux (the /api/backup endpoint is Windows-DPAPI-only). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-02 21:49:58 +02:00
parent e352aaeaac
commit 999d6e05e7
6 changed files with 298 additions and 0 deletions
@@ -0,0 +1,97 @@
+using JobTrackerApi.Services;
+using Microsoft.Data.Sqlite;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace JobTrackerApi.Tests;
+
+public sealed class DatabaseBackupRunnerTests : IDisposable
+{
+    private readonly string _root;
+
+    public DatabaseBackupRunnerTests()
+    {
+        _root = Path.Combine(Path.GetTempPath(), $"jt-backup-tests-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(_root);
+    }
+
+    public void Dispose()
+    {
+        SqliteConnection.ClearAllPools();
+        try { Directory.Delete(_root, recursive: true); } catch (IOException) { }
+    }
+
+    private string CreateSourceDb(out string connectionString)
+    {
+        var dbPath = Path.Combine(_root, "source.db");
+        connectionString = $"Data Source={dbPath}";
+        using var connection = new SqliteConnection(connectionString);
+        connection.Open();
+        using var command = connection.CreateCommand();
+        command.CommandText = "CREATE TABLE Sample (Id INTEGER PRIMARY KEY, Name TEXT); INSERT INTO Sample (Name) VALUES ('alpha'), ('beta');";
+        command.ExecuteNonQuery();
+        return dbPath;
+    }
+
+    private SqliteDatabaseBackupRunner CreateRunner(string connectionString, int retainCount = 14)
+        => new(connectionString, Path.Combine(_root, "backups"), retainCount, NullLogger<SqliteDatabaseBackupRunner>.Instance);
+
+    [Fact]
+    public async Task RunOnce_creates_a_restorable_backup_file()
+    {
+        CreateSourceDb(out var connectionString);
+        var runner = CreateRunner(connectionString);
+
+        var backupPath = await runner.RunOnceAsync(CancellationToken.None);
+
+        Assert.NotNull(backupPath);
+        Assert.True(File.Exists(backupPath));
+
+        await using var verify = new SqliteConnection($"Data Source={backupPath}");
+        await verify.OpenAsync();
+        await using var count = verify.CreateCommand();
+        count.CommandText = "SELECT COUNT(*) FROM Sample";
+        Assert.Equal(2L, (long)(await count.ExecuteScalarAsync())!);
+    }
+
+    [Fact]
+    public async Task RunOnce_prunes_backups_beyond_retention()
+    {
+        CreateSourceDb(out var connectionString);
+        var runner = CreateRunner(connectionString, retainCount: 2);
+        var backupsRoot = runner.BackupsRoot;
+        Directory.CreateDirectory(backupsRoot);
+
+        for (var i = 0; i < 3; i++)
+        {
+            var stale = Path.Combine(backupsRoot, $"{SqliteDatabaseBackupRunner.BackupFilePrefix}stale{i}.db");
+            File.WriteAllText(stale, "stale");
+            File.SetLastWriteTimeUtc(stale, DateTime.UtcNow.AddDays(-10 - i));
+        }
+
+        await runner.RunOnceAsync(CancellationToken.None);
+
+        var remaining = Directory.GetFiles(backupsRoot, $"{SqliteDatabaseBackupRunner.BackupFilePrefix}*.db");
+        Assert.Equal(2, remaining.Length);
+        Assert.Contains(remaining, f => Path.GetFileName(f).Contains("stale0"));
+    }
+
+    [Fact]
+    public void Latest_backup_timestamp_reflects_newest_file()
+    {
+        CreateSourceDb(out var connectionString);
+        var runner = CreateRunner(connectionString);
+
+        Assert.Null(runner.GetLatestBackupUtc());
+
+        Directory.CreateDirectory(runner.BackupsRoot);
+        var file = Path.Combine(runner.BackupsRoot, $"{SqliteDatabaseBackupRunner.BackupFilePrefix}x.db");
+        File.WriteAllText(file, "x");
+        var stamp = DateTime.UtcNow.AddHours(-3);
+        File.SetLastWriteTimeUtc(file, stamp);
+
+        var latest = runner.GetLatestBackupUtc();
+        Assert.NotNull(latest);
+        Assert.True(Math.Abs((latest!.Value - stamp).TotalSeconds) < 2);
+    }
+}