From 6816d8c5c196679868bd4a6cf30b696f61eb35c6 Mon Sep 17 00:00:00 2001
From: Adam Chance <6444703+drakon64@users.noreply.github.com>
Date: Mon, 23 Dec 2024 21:21:10 +0000
Subject: [PATCH] Delete queued tasks if their parent job is cancelled

---
 Ktisis.Common/Clients/GoogleClient.cs         | 21 +++++++++++++
 .../GitHubWebhookEventProcessor.cs            | 31 +++++++++++--------
 tofu/ktisis/cloud_tasks.tf                    |  7 ++++-
 3 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/Ktisis.Common/Clients/GoogleClient.cs b/Ktisis.Common/Clients/GoogleClient.cs
index ecd75a9..54b37c2 100644
--- a/Ktisis.Common/Clients/GoogleClient.cs
+++ b/Ktisis.Common/Clients/GoogleClient.cs
@@ -78,6 +78,27 @@ public static async Task CreateTask(CreateCloudTask task)
         await Console.Out.WriteLineAsync(await request.Content.ReadAsStringAsync());
     }
 
+    public static async Task DeleteTask(string task)
+    {
+        var accessToken = await GetAccessToken();
+
+        var request = await Ktisis.HttpClient.SendAsync(
+            new HttpRequestMessage
+            {
+                Method = HttpMethod.Delete,
+                Headers =
+                {
+                    { "Authorization", $"{accessToken.TokenType} {accessToken.AccessToken}" },
+                },
+                RequestUri = new Uri(
+                    $"https://cloudtasks.googleapis.com/v2/projects/{Project}/locations/{Region}/queues/{Queue}/tasks/{task}"
+                ),
+            }
+        );
+
+        await Console.Out.WriteLineAsync(await request.Content.ReadAsStringAsync());
+    }
+
     public static async Task<ZoneOperation> CreateInstance(CreateInstance instance, string zone)
     {
         var accessToken = await GetAccessToken();
diff --git a/Ktisis.Receiver/EventProcessors/GitHubWebhookEventProcessor.cs b/Ktisis.Receiver/EventProcessors/GitHubWebhookEventProcessor.cs
index 0ad08a1..6e70a52 100644
--- a/Ktisis.Receiver/EventProcessors/GitHubWebhookEventProcessor.cs
+++ b/Ktisis.Receiver/EventProcessors/GitHubWebhookEventProcessor.cs
@@ -10,6 +10,7 @@
 using Octokit.Webhooks;
 using Octokit.Webhooks.Events;
 using Octokit.Webhooks.Events.WorkflowJob;
+using Octokit.Webhooks.Models.WorkflowJobEvent;
 
 namespace Ktisis.Receiver.EventProcessors;
 
@@ -42,6 +43,9 @@ await Console.Out.WriteLineAsync(
             return;
         }
 
+        var instanceName =
+            $"{workflowJobEvent.Repository!.FullName.Replace('/', '-')}-{workflowJobEvent.WorkflowJob.RunId}-{workflowJobEvent.WorkflowJob.Id}";
+
         switch (workflowJobEvent.Action)
         {
             case "queued":
@@ -96,16 +100,13 @@ await Console.Out.WriteLineAsync(
                     }
                 }
 
-                var name =
-                    $"{workflowJobEvent.Repository!.FullName.Replace('/', '-')}-{workflowJobEvent.WorkflowJob.RunId}-{workflowJobEvent.WorkflowJob.Id}";
-
                 await GoogleClient.CreateTask(
                     new CreateCloudTask
                     {
                         Task = new CloudTask
                         {
                             Name =
-                                $"projects/{Program.Project}/locations/{Program.Region}/queues/{Program.Queue}/tasks/{Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(name)))}",
+                                $"projects/{Program.Project}/locations/{Program.Region}/queues/{Program.Queue}/tasks/{Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(instanceName)))}",
                             HttpRequest = new CloudTaskHttpRequest
                             {
                                 Url = Program.TaskServiceUrl,
@@ -117,7 +118,7 @@ await GoogleClient.CreateTask(
                                                 Zone = zone,
                                                 Instance = new CreateInstance
                                                 {
-                                                    Name = name,
+                                                    Name = instanceName,
                                                     MachineType =
                                                         $"projects/{GoogleClient.Project}/zones/{zone}/machineTypes/{machineType}",
                                                     NetworkInterfaces =
@@ -223,14 +224,18 @@ rm actions-runner-linux-{runnerArchitecture}-2.321.0.tar.gz
             }
             case "completed":
             {
-                // TODO: Get the instance zone rather than brute-forcing
-                foreach (var zone in Program.Zones)
-                {
-                    await GoogleClient.DeleteInstance(
-                        workflowJobEvent.WorkflowJob.RunnerName!,
-                        zone
-                    );
-                }
+                if (
+                    workflowJobEvent.WorkflowJob.Conclusion!.Value
+                    == WorkflowJobConclusion.Cancelled
+                )
+                    await GoogleClient.DeleteTask(instanceName);
+                else
+                    // TODO: Get the instance zone rather than brute-forcing
+                    foreach (var zone in Program.Zones)
+                        await GoogleClient.DeleteInstance(
+                            workflowJobEvent.WorkflowJob.RunnerName!,
+                            zone
+                        );
 
                 break;
             }
diff --git a/tofu/ktisis/cloud_tasks.tf b/tofu/ktisis/cloud_tasks.tf
index 36aed0f..2d4fa75 100644
--- a/tofu/ktisis/cloud_tasks.tf
+++ b/tofu/ktisis/cloud_tasks.tf
@@ -24,7 +24,12 @@ resource "google_cloud_tasks_queue" "cloud_tasks" {
 }
 
 resource "google_cloud_tasks_queue_iam_member" "ktisis" {
+  for_each = toset([
+    "enqueuer",
+    "taskDeleter",
+  ])
+  
   member = google_service_account.ktisis_receiver.member
   name   = google_cloud_tasks_queue.cloud_tasks.name
-  role   = "roles/cloudtasks.enqueuer"
+  role   = "roles/cloudtasks.${each.value}"
 }