CDNs found by themselves, and servers followed through time

PrivaPub now finds CDNs three ways, best first: the address ranges the
CDNs publish (Cloudflare, Fastly, Amazon CloudFront, Bunny, Gcore,
Imperva), downloaded daily by CdnUpdater and kept in CdnRangeSet; the
CDN's fingerprint in the responses it already gets from a server
(EdgeHintsHandler on the federation client); and the networks that carry
only a CDN. The fixed ASN list is gone; ASNs shared with plain hosting
(AWS, DataPacket) no longer hide a server. A server's Geo records the
CDN, its domain and how it was found, and weekly snapshots now keep the
city and coordinates too.

Servers through time (ServerPlaces): /instances/:host/history lists a
server's weekly snapshots, a CDN-fronted server's geo names the CDN's
domain and where the server was before it (before_cdn), and
/api/privapub/v1/cdns and /cdns/:domain group servers by CDN with week
by week who joined and who left. Owner decisions recorded in ROADMAP.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub.Tests/Infrastructure/CdnUpdaterTests.cs

@@ -0,0 +1,105 @@
+using Microsoft.Extensions.Logging.Abstractions;
+
+using MongoDB.Entities;
+
+using PrivaPub.Infrastructure.Geo;
+using PrivaPub.Infrastructure.Statistics;
+using PrivaPub.Models.Jobs;
+using PrivaPub.Tests.Support;
+
+using System.Net;
+
+namespace PrivaPub.Tests.Infrastructure
+{
+	[Trait("Category", "Integration")]
+	public sealed class CdnUpdaterTests : IAsyncLifetime
+	{
+		Peer _peer;
+		CdnRanges _ranges;
+		CdnUpdater _updater;
+		string _key;
+
+		public async ValueTask InitializeAsync()
+		{
+			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
+			_peer = await Peer.Start();
+			_ranges = new CdnRanges();
+			_updater = new CdnUpdater(new Clients(), new StaticOptions<StatisticsOptions>(new StatisticsOptions()), _ranges, NullLogger<CdnUpdater>.Instance);
+			_key = $"edge{Guid.NewGuid():N}.example";
+		}
+
+		public async ValueTask DisposeAsync()
+		{
+			if (_peer != default)
+				await _peer.DisposeAsync();
+		}
+
+		sealed class Clients : IHttpClientFactory
+		{
+			public HttpClient CreateClient(string name) => new();
+		}
+
+		CdnProvider Provider() => new("Test Edge", _key, Array.Empty<int>(), new[]
+		{
+			new CdnList($"{_peer.A}/edge/v4", CdnListFormat.Lines),
+			new CdnList($"{_peer.A}/edge/v6", CdnListFormat.StringArray)
+		}, _ => false);
+
+		static CancellationToken Token => TestContext.Current.CancellationToken;
+
+		[Fact]
+		public async Task The_published_ranges_are_downloaded_stored_and_used()
+		{
+			_peer.ServeText("/edge/v4", "198.51.100.0/24\n", "text/plain");
+			_peer.ServeText("/edge/v6", """["2001:db8::/32","192.0.2.9"]""", "application/json");
+
+			Assert.Equal(1, await _updater.Update(new[] { Provider() }, Token));
+
+			var stored = await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteSingleAsync(Token);
+			Assert.Equal(new[] { "198.51.100.0/24", "2001:db8::/32", "192.0.2.9/32" }, stored.Ranges);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("198.51.100.20"))?.Name);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("192.0.2.9"))?.Name);
+
+			var restarted = new CdnRanges();
+			await restarted.Load(Token);
+			Assert.Equal("Test Edge", restarted.Of(IPAddress.Parse("2001:db8::7"))?.Name);
+		}
+
+		[Theory]
+		[InlineData("not a network")]
+		[InlineData("")]
+		public async Task A_broken_or_empty_list_keeps_the_stored_ranges(string broken)
+		{
+			_peer.ServeText("/edge/v4", "198.51.100.0/24", "text/plain");
+			_peer.ServeText("/edge/v6", "[]", "application/json");
+			Assert.Equal(1, await _updater.Update(new[] { Provider() }, Token));
+
+			_peer.ServeText("/edge/v4", broken, "text/plain");
+			Assert.Equal(0, await _updater.Update(new[] { Provider() }, Token));
+
+			Assert.Equal(new[] { "198.51.100.0/24" }, (await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteSingleAsync(Token)).Ranges);
+			Assert.Equal("Test Edge", _ranges.Of(IPAddress.Parse("198.51.100.1"))?.Name);
+		}
+
+		// The real lists, from the CDNs themselves: set PRIVAPUB_TEST_CDN_LIVE=1 to check that every format still parses.
+		[Fact]
+		public async Task Every_cdns_real_list_still_parses()
+		{
+			Assert.SkipUnless(Environment.GetEnvironmentVariable("PRIVAPUB_TEST_CDN_LIVE") == "1", "set PRIVAPUB_TEST_CDN_LIVE=1 to download the real lists");
+			var listed = CdnCatalog.All.Where(p => p.Lists.Length > 0).ToList();
+
+			Assert.Equal(listed.Count, await _updater.Update(listed, Token));
+
+			Assert.Equal("Cloudflare", _ranges.Of(IPAddress.Parse("104.16.0.1"))?.Name);
+			foreach (var provider in listed)
+				Assert.True(_ranges.Status[provider.Key].Ranges > 0, provider.Name);
+		}
+
+		[Fact]
+		public async Task An_unreachable_list_changes_nothing()
+		{
+			Assert.Equal(0, await _updater.Update(new[] { Provider() }, Token));
+			Assert.False(await DB.Default.Find<CdnRangeSet>().Match(s => s.Key == _key).ExecuteAnyAsync(Token));
+		}
+	}
+}