feat(13-03): implement DockerHubSource and KubernetesSource

- DockerHub searches hub.docker.com v2 search API for repos matching provider keywords
- Kubernetes searches Artifact Hub for operators/manifests with kind-aware URL paths
- Both sources: context cancellation, nil registry, httptest-based tests

pkg/recon/sources/kubernetes.go

@@ -0,0 +1,156 @@
+package sources
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	"golang.org/x/time/rate"
+
+	"github.com/salvacybersec/keyhunter/pkg/providers"
+	"github.com/salvacybersec/keyhunter/pkg/recon"
+)
+
+// KubernetesSource searches Artifact Hub for Kubernetes operators and manifests
+// matching provider keywords. This discovers publicly published K8s packages
+// that may embed API keys in their manifests or values files.
+//
+// Emits one Finding per package result, tagged SourceType=recon:k8s.
+type KubernetesSource struct {
+	// BaseURL defaults to https://artifacthub.io. Tests override with httptest URL.
+	BaseURL string
+	// Registry drives the keyword query list via BuildQueries.
+	Registry *providers.Registry
+	// Limiters is the shared recon.LimiterRegistry.
+	Limiters *recon.LimiterRegistry
+	// Client is the shared retry HTTP wrapper. If nil, a default is used.
+	Client *Client
+}
+
+// Compile-time assertion that KubernetesSource satisfies recon.ReconSource.
+var _ recon.ReconSource = (*KubernetesSource)(nil)
+
+func (s *KubernetesSource) Name() string          { return "k8s" }
+func (s *KubernetesSource) RateLimit() rate.Limit { return rate.Every(3 * time.Second) }
+func (s *KubernetesSource) Burst() int            { return 1 }
+func (s *KubernetesSource) RespectsRobots() bool  { return true }
+
+// Enabled always returns true: Artifact Hub search is unauthenticated.
+func (s *KubernetesSource) Enabled(_ recon.Config) bool { return true }
+
+// Sweep iterates provider keywords, searches Artifact Hub for Kubernetes
+// operators (kind=6), and emits a Finding for each result.
+func (s *KubernetesSource) Sweep(ctx context.Context, _ string, out chan<- recon.Finding) error {
+	base := s.BaseURL
+	if base == "" {
+		base = "https://artifacthub.io"
+	}
+	client := s.Client
+	if client == nil {
+		client = NewClient()
+	}
+
+	queries := BuildQueries(s.Registry, "k8s")
+	if len(queries) == 0 {
+		return nil
+	}
+
+	for _, q := range queries {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		if s.Limiters != nil {
+			if err := s.Limiters.Wait(ctx, s.Name(), s.RateLimit(), s.Burst(), false); err != nil {
+				return err
+			}
+		}
+
+		// kind left empty to search across all Kubernetes-related package types.
+		endpoint := fmt.Sprintf("%s/api/v1/packages/search?ts_query_web=%s&limit=20",
+			base, url.QueryEscape(q))
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+		if err != nil {
+			return fmt.Errorf("k8s: build req: %w", err)
+		}
+		req.Header.Set("Accept", "application/json")
+
+		resp, err := client.Do(ctx, req)
+		if err != nil {
+			continue
+		}
+
+		var parsed k8sSearchResponse
+		decErr := json.NewDecoder(resp.Body).Decode(&parsed)
+		_ = resp.Body.Close()
+		if decErr != nil {
+			continue
+		}
+
+		for _, pkg := range parsed.Packages {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+
+			repoName := ""
+			if pkg.Repository.Name != "" {
+				repoName = pkg.Repository.Name
+			}
+
+			kindPath := k8sKindPath(pkg.Repository.Kind)
+			sourceURL := fmt.Sprintf("https://artifacthub.io/packages/%s/%s/%s",
+				kindPath, repoName, pkg.NormalizedName)
+			if base != "https://artifacthub.io" {
+				sourceURL = fmt.Sprintf("%s/packages/%s/%s/%s",
+					base, kindPath, repoName, pkg.NormalizedName)
+			}
+
+			f := recon.Finding{
+				ProviderName: "",
+				Source:       sourceURL,
+				SourceType:   "recon:k8s",
+				Confidence:   "low",
+				DetectedAt:   time.Now(),
+			}
+			select {
+			case out <- f:
+			case <-ctx.Done():
+				return ctx.Err()
+			}
+		}
+	}
+	return nil
+}
+
+type k8sSearchResponse struct {
+	Packages []k8sPackage `json:"packages"`
+}
+
+type k8sPackage struct {
+	PackageID      string    `json:"package_id"`
+	Name           string    `json:"name"`
+	NormalizedName string    `json:"normalized_name"`
+	Repository     k8sRepo   `json:"repository"`
+}
+
+type k8sRepo struct {
+	Name string `json:"name"`
+	Kind int    `json:"kind"`
+}
+
+// k8sKindPath maps Artifact Hub kind integers to URL path segments.
+func k8sKindPath(kind int) string {
+	switch kind {
+	case 0:
+		return "helm"
+	case 6:
+		return "kube-operator"
+	case 7:
+		return "kubectl"
+	default:
+		return "other"
+	}
+}