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/Federation/Objects/InstanceDescriber.cs

@@ -1,4 +1,4 @@
-using MongoDB.Entities;
+using MongoDB.Entities;
 
 using PrivaPub.Infrastructure.Geo;
 using PrivaPub.Infrastructure.Http;
@@ -18,12 +18,17 @@ namespace PrivaPub.Federation.Objects
 		readonly IFederationHttp _http;
 		readonly IGeoLocator _geo;
 		readonly IConnectedAddresses _addresses;
+		readonly ICdnRanges _cdnRanges;
+		readonly IEdgeHints _edges;
 
-		public InstanceDescriber(IFederationHttp http, IGeoLocator geo = default, IConnectedAddresses addresses = default)
+		public InstanceDescriber(IFederationHttp http, IGeoLocator geo = default, IConnectedAddresses addresses = default, ICdnRanges cdnRanges = default,
+			IEdgeHints edges = default)
 		{
 			_http = http;
 			_geo = geo;
 			_addresses = addresses;
+			_cdnRanges = cdnRanges;
+			_edges = edges;
 		}
 
 		public JobKind Kind => JobKind.DescribeInstance;
@@ -145,35 +150,57 @@ namespace PrivaPub.Federation.Objects
 				.Modify(s => s.RegistrationMode, instance?.RegistrationMode)
 				.Modify(s => s.Languages, instance?.Languages)
 				.Modify(s => s.Country, instance?.Geo?.Country)
+				.Modify(s => s.City, instance?.Geo?.City)
+				.Modify(s => s.Latitude, instance?.Geo?.Latitude)
+				.Modify(s => s.Longitude, instance?.Geo?.Longitude)
 				.Modify(s => s.Asn, instance?.Geo?.Asn)
 				.Modify(s => s.Cdn, instance?.Geo?.Cdn)
+				.Modify(s => s.CdnDomain, instance?.Geo?.CdnDomain)
+				.Modify(s => s.CdnSource, instance?.Geo?.CdnSource)
 				.Modify(s => s.Ipv6, instance?.Geo?.Ipv6)
 				.Option(o => o.IsUpsert = true)
 				.ExecuteAsync(token);
 			return facts != default;
 		}
 
+		// Where the address we reached sits, and the CDN in front of it, found by its published ranges, then by the
+		// fingerprint in the responses we just got, then by a network that carries only a CDN.
 		InstanceGeo Locate(string host)
 		{
-			var reached = _addresses?.Of(new Uri(Address($"https://{host}/")).Host);
+			var reachedHost = new Uri(Address($"https://{host}/")).Host;
+			var reached = _addresses?.Of(reachedHost);
 			var fix = reached == default ? default : _geo?.Locate(reached);
-			if (fix == default)
+			var (cdn, cdnSource) = Cdn(reached, reachedHost, fix?.Asn, _cdnRanges, _edges);
+			if (fix == default && cdn == default)
 				return default;
 			return new InstanceGeo
 			{
-				Country = fix.Country,
-				City = fix.City,
-				Latitude = fix.Latitude,
-				Longitude = fix.Longitude,
-				Asn = fix.Asn,
-				AsnOrg = fix.AsnOrg,
-				Cdn = CdnNetworks.Of(fix.Asn),
-				Ipv6 = reached.AddressFamily == AddressFamily.InterNetworkV6,
-				Source = _geo.Source,
+				Country = fix?.Country,
+				City = fix?.City,
+				Latitude = fix?.Latitude,
+				Longitude = fix?.Longitude,
+				Asn = fix?.Asn,
+				AsnOrg = fix?.AsnOrg,
+				Cdn = cdn?.Name,
+				CdnDomain = cdn?.Domain,
+				CdnSource = cdnSource,
+				Ipv6 = reached?.AddressFamily == AddressFamily.InterNetworkV6,
+				Source = _geo?.Source,
 				LocatedAt = DateTime.UtcNow
 			};
 		}
 
+		public static (CdnProvider Cdn, string Source) Cdn(System.Net.IPAddress address, string host, int? asn, ICdnRanges ranges, IEdgeHints edges)
+		{
+			if (ranges?.Of(address) is { } listed)
+				return (listed, "ranges");
+			if (edges?.Of(host) is { } hinted)
+				return (hinted, "headers");
+			if (CdnCatalog.OfAsn(asn) is { } network)
+				return (network, "asn");
+			return default;
+		}
+
 		//where an https address is fetched from: itself, except in tests, which point it at a plain-http peer
 		protected virtual string Address(string url) => url;
 	}