From b2898f91836ac2fe0b4930b2867eeae6919697e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maximilian=20Pa=C3=9F?=
 <22845248+mpass99@users.noreply.github.com>
Date: Fri, 20 Oct 2023 18:24:38 +0200
Subject: [PATCH] Fix List of the Environments with fetch.

Before the List function dropped all idleRunners of all environments when fetch was set.

Additionally, the replaced environment was not destroyed properly so that a goroutine for it and for all its idle runners remained running.
---
 internal/environment/nomad_manager.go | 40 +++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/internal/environment/nomad_manager.go b/internal/environment/nomad_manager.go
index 7fa9cfe..8e55ea7 100644
--- a/internal/environment/nomad_manager.go
+++ b/internal/environment/nomad_manager.go
@@ -87,14 +87,50 @@ func (m *NomadEnvironmentManager) Get(id dto.EnvironmentID, fetch bool) (
 
 func (m *NomadEnvironmentManager) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
 	if fetch {
-		err := m.Load()
-		if err != nil {
+		if err := m.fetchEnvironments(); err != nil {
 			return nil, err
 		}
 	}
 	return m.runnerManager.ListEnvironments(), nil
 }
 
+func (m *NomadEnvironmentManager) fetchEnvironments() error {
+	remoteEnvironmentList, err := m.api.LoadEnvironmentJobs()
+	if err != nil {
+		return fmt.Errorf("failed fetching environments: %w", err)
+	}
+	remoteEnvironments := make(map[string]*nomadApi.Job)
+
+	// Update local environments from remote environments.
+	for _, job := range remoteEnvironmentList {
+		remoteEnvironments[*job.ID] = job
+		id, err := nomad.EnvironmentIDFromTemplateJobID(*job.ID)
+		if err != nil {
+			return fmt.Errorf("cannot parse environment id: %w", err)
+		}
+
+		if localEnvironment, ok := m.runnerManager.GetEnvironment(id); ok {
+			fetchedEnvironment := newNomadEnvironmentFromJob(job, m.api)
+			localEnvironment.SetConfigFrom(fetchedEnvironment)
+			// We destroy only this (second) local reference to the environment.
+			if err = fetchedEnvironment.Delete(true); err != nil {
+				log.WithError(err).Warn("Failed to remove environment locally")
+			}
+		} else {
+			m.runnerManager.StoreEnvironment(newNomadEnvironmentFromJob(job, m.api))
+		}
+	}
+
+	// Remove local environments that are not remote environments.
+	for _, localEnvironment := range m.runnerManager.ListEnvironments() {
+		if _, ok := remoteEnvironments[localEnvironment.ID().ToString()]; !ok {
+			err := localEnvironment.Delete(true)
+			log.WithError(err).Warn("Failed to remove environment locally")
+		}
+	}
+	return nil
+}
+
 func (m *NomadEnvironmentManager) CreateOrUpdate(
 	id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest, ctx context.Context) (created bool, err error) {
 	// Check if execution environment is already existing (in the local memory).