chore: import upstream snapshot with attribution

api/http/handler/endpointproxy/proxy_docker.go

@@ -0,0 +1,61 @@
+package endpointproxy
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"strings"
+
+	portainer "github.com/portainer/portainer/api"
+	httperror "github.com/portainer/portainer/pkg/libhttp/error"
+	"github.com/portainer/portainer/pkg/libhttp/request"
+)
+
+func (handler *Handler) proxyRequestsToDockerAPI(w http.ResponseWriter, r *http.Request) *httperror.HandlerError {
+	endpointID, err := request.RetrieveNumericRouteVariableValue(r, "id")
+	if err != nil {
+		return httperror.BadRequest("Invalid environment identifier route variable", err)
+	}
+
+	endpoint, err := handler.DataStore.Endpoint().Endpoint(portainer.EndpointID(endpointID))
+	if handler.DataStore.IsErrObjectNotFound(err) {
+		return httperror.NotFound("Unable to find an environment with the specified identifier inside the database", err)
+	} else if err != nil {
+		return httperror.InternalServerError("Unable to find an environment with the specified identifier inside the database", err)
+	}
+
+	err = handler.requestBouncer.AuthorizedEndpointOperation(r, endpoint)
+	if err != nil {
+		return httperror.Forbidden("Permission denied to access environment", err)
+	}
+
+	if endpoint.Type == portainer.EdgeAgentOnDockerEnvironment {
+		if endpoint.EdgeID == "" {
+			return httperror.InternalServerError("No Edge agent registered with the environment", errors.New("No agent available"))
+		}
+
+		_, err := handler.ReverseTunnelService.TunnelAddr(endpoint)
+		if err != nil {
+			return httperror.InternalServerError("Unable to get the active tunnel", err)
+		}
+	}
+
+	var proxy http.Handler
+	proxy = handler.ProxyManager.GetEndpointProxy(endpoint)
+	if proxy == nil {
+		proxy, err = handler.ProxyManager.CreateAndRegisterEndpointProxy(endpoint)
+		if err != nil {
+			return httperror.InternalServerError("Unable to create proxy", err)
+		}
+	}
+
+	id := strconv.Itoa(endpointID)
+
+	prefix := "/" + id + "/agent/docker"
+	if !strings.HasPrefix(r.URL.Path, prefix) {
+		prefix = "/" + id + "/docker"
+	}
+
+	http.StripPrefix(prefix, proxy).ServeHTTP(w, r)
+	return nil
+}