Add statistics route for execution environments

* Add statistics route for execution environments

* Add maximum to port api definition

Co-authored-by: Sebastian Serth <MrSerth@users.noreply.github.com>

internal/runner/storage.go

@@ -6,6 +6,9 @@ import (
 
 // Storage is an interface for storing runners.
 type Storage interface {
+	// List returns all runners from the storage.
+	List() []Runner
+
 	// Add adds a runner to the storage.
 	// It overwrites the old runner if one with the same id was already stored.
 	Add(Runner)
@@ -41,6 +44,15 @@ func NewLocalRunnerStorage() *localRunnerStorage {
 	}
 }
 
+func (s *localRunnerStorage) List() (r []Runner) {
+	s.RLock()
+	defer s.RUnlock()
+	for _, value := range s.runners {
+		r = append(r, value)
+	}
+	return r
+}
+
 func (s *localRunnerStorage) Add(r Runner) {
 	s.Lock()
 	defer s.Unlock()