feat: initial commit

middleware/apikey.go

@@ -0,0 +1,59 @@
+package middleware
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	"github.com/99designs/gqlgen/graphql"
+	"github.com/apex/log"
+)
+
+type ContextKey string
+
+const (
+	ApiKey = ContextKey("apikey")
+)
+
+func NewApiKey(apiKey string, logger log.Interface) *ApiKeyMiddleware {
+	return &ApiKeyMiddleware{
+		apiKey: apiKey,
+	}
+}
+
+type ApiKeyMiddleware struct {
+	apiKey string
+}
+
+func (m *ApiKeyMiddleware) Handler(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		header := r.Header.Get("x-api-key")
+		if len(header) == 0 {
+			next.ServeHTTP(w, r)
+		} else {
+			ctx := context.WithValue(r.Context(), ApiKey, header)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		}
+	})
+}
+
+func (m *ApiKeyMiddleware) Directive(ctx context.Context, obj interface{}, next graphql.Resolver) (res interface{}, err error) {
+	key, err := m.fromContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if key != m.apiKey {
+		return nil, fmt.Errorf("invalid API-key")
+	}
+	return next(ctx)
+}
+
+func (m *ApiKeyMiddleware) fromContext(ctx context.Context) (string, error) {
+	if value := ctx.Value(ApiKey); value != nil {
+		if u, ok := value.(string); ok {
+			return u, nil
+		}
+		return "", fmt.Errorf("current API-key is in wrong format")
+	}
+	return "", fmt.Errorf("no API-key found")
+}