ctcloud: CertSpotter-backed CT cloud-resource monitor

Single stateless Go process that consumes CT logs via embedded (patched)
CertSpotter internals, classifies cloud/database/storage DNS identifiers
in-process with a zero-allocation classifier, enriches via round-robin DNS
resolvers with CNAME following, and batch-writes useful findings to PostgreSQL.

- third_party/certspotter: 2-hunk IdentifierSink patch, no stdout/JSON/files
- internal/classify: AWS/Azure/GCP/Firebase/Cloudflare R2/DigitalOcean/Supabase/OCI
- internal/dns: sharded bounded TTL cache, multi-resolver load balancing + failover
- internal/pipeline: bounded queues, dedup, direct-priority load shedding
- internal/store: pgx batch writer, Postgres CT checkpoints (no cert contents)
- internal/probe: optional non-destructive reachability checks (off by default)
- Docker: distroless non-root, read-only rootfs, no app volume, resource limits
- tests enforce 0 allocs/op on the classifier and sink hot path

internal/classify/azure.go

@@ -0,0 +1,113 @@
+package classify
+
+import "tea.karlcom.de/karl/bucketeer/internal/model"
+
+func azure(service model.Service, resource, region string) model.Match {
+	return model.Match{
+		Provider:         model.ProviderAzure,
+		Service:          service,
+		ResourceSpecific: true,
+		Region:           region,
+		Resource:         resource,
+	}
+}
+
+// classifyAzureCore handles *.blob|dfs|file|queue|table|web.core.windows.net.
+func classifyAzureCore(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 5 || s.label(n-1) != "net" || s.label(n-2) != "windows" || s.label(n-3) != "core" {
+		return model.Match{}, false
+	}
+	svc := s.label(n - 4)
+	resource := s.label(0)
+	if resource == "" {
+		return model.Match{}, false
+	}
+	switch svc {
+	case "blob", "dfs":
+		return azure(model.ServiceBlobStorage, resource, ""), true
+	case "file":
+		return azure(model.ServiceFileStorage, resource, ""), true
+	case "queue":
+		return azure(model.ServiceQueue, resource, ""), true
+	case "table":
+		return azure(model.ServiceTableStorage, resource, ""), true
+	case "web":
+		return azure(model.ServiceWebApp, resource, ""), true
+	}
+	return model.Match{}, false
+}
+
+// classifyAzureDatabase handles <server>.database.windows.net.
+func classifyAzureDatabase(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 4 || s.label(n-1) != "net" || s.label(n-2) != "windows" || s.label(n-3) != "database" {
+		return model.Match{}, false
+	}
+	return azure(model.ServiceDatabase, s.label(0), ""), true
+}
+
+// classifyAzureFlexibleServer handles <server>.{postgres,mysql}.database.azure.com.
+func classifyAzureFlexibleServer(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 5 || s.label(n-1) != "com" || s.label(n-2) != "azure" || s.label(n-3) != "database" {
+		return model.Match{}, false
+	}
+	switch s.label(n - 4) {
+	case "postgres":
+		return azure(model.ServicePostgres, s.label(0), ""), true
+	case "mysql":
+		return azure(model.ServiceMySQL, s.label(0), ""), true
+	}
+	return model.Match{}, false
+}
+
+// classifyAzureDocuments handles <account>.documents.azure.com (Cosmos DB).
+func classifyAzureDocuments(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 4 || s.label(n-1) != "com" || s.label(n-2) != "azure" || s.label(n-3) != "documents" {
+		return model.Match{}, false
+	}
+	return azure(model.ServiceCosmosDB, s.label(0), ""), true
+}
+
+// classifyAzureCosmos handles <account>.{mongo,cassandra,gremlin}.cosmos.azure.com.
+func classifyAzureCosmos(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 5 || s.label(n-1) != "com" || s.label(n-2) != "azure" || s.label(n-3) != "cosmos" {
+		return model.Match{}, false
+	}
+	switch s.label(n - 4) {
+	case "mongo", "cassandra", "gremlin":
+		return azure(model.ServiceCosmosDB, s.label(0), ""), true
+	}
+	return model.Match{}, false
+}
+
+// classifyAzureRedis handles <name>.redis.cache.windows.net.
+func classifyAzureRedis(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 5 || s.label(n-1) != "net" || s.label(n-2) != "windows" ||
+		s.label(n-3) != "cache" || s.label(n-4) != "redis" {
+		return model.Match{}, false
+	}
+	return azure(model.ServiceRedis, s.label(0), ""), true
+}
+
+// classifyAzureManagedRedis handles <name>.redis.azure.net.
+func classifyAzureManagedRedis(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 4 || s.label(n-1) != "net" || s.label(n-2) != "azure" || s.label(n-3) != "redis" {
+		return model.Match{}, false
+	}
+	return azure(model.ServiceRedis, s.label(0), ""), true
+}
+
+// classifyAzureSearch handles <service>.search.windows.net.
+func classifyAzureSearch(s *scanner) (model.Match, bool) {
+	n := s.n
+	if n < 4 || s.label(n-1) != "net" || s.label(n-2) != "windows" || s.label(n-3) != "search" {
+		return model.Match{}, false
+	}
+	return azure(model.ServiceSearch, s.label(0), ""), true
+}