Add script to guide developers through setting up their environment t…

…o allow locally debugging the Kubernetes Agent (#1007)

* Add initial script with changes

* add comment

* Update setup-k8s-agent-for-local-debug.sh

Co-authored-by: Kevin Tchang <kevin.tchang@octopus.com>

* address code review comments

* Add documentation about debugging in the read me

---------

Co-authored-by: Kevin Tchang <kevin.tchang@octopus.com>

README.md

@@ -99,6 +99,12 @@ Currently we can only debug netcore apps running in WSL from VSCode, Visual Stud
     "problemMatcher": "$msCompile"
 }
 ```
+## Debugging the Kubernetes Agent Tentacle
+
+The Kubernetes Agent Tentacle is a bit more complex to debug, as it normally runs inside a Kubernetes Pod. To debug it locally, you can run the `setup-k8s-agent-for-local-debug.sh` script in the root of this repo which will guide you through the process of installing a specially configured kind cluster, deploying the agent to it and then scaling back the installed agent so you can run a local copy to take it's place.
+
+NOTE: This script has only been tested on MacOS so far and requires Docker Desktop, Kubectl, Go CLI and Kind to be installed. It is also only for the Kubernetes Agent Tentacle running as a Deployment Target, not as a Worker.
+
 ## Additional Resources
 
 - Scripts to help with manual testing can be found in [./testing](./testing/README.md).

k8s-agent-debug-cluster-config/k8s-agent-debug-cluster.yaml

@@ -0,0 +1,8 @@
+kind: Cluster
+apiVersion: kind.x-k8s.io/v1alpha4
+name: k8s-agent-debug-cluster
+nodes:
+- role: control-plane
+  extraMounts:
+  - hostPath: /tmp/k8s-agent-debug-vol
+    containerPath: /k8s-agent-debug-vol

k8s-agent-debug-cluster-config/launchSettings.template.json

@@ -0,0 +1,28 @@
+{
+  "profiles": {
+    "Octopus Kubernetes Agent": {
+      "commandName": "Project",
+      "commandLineArgs": "agent --instance Tentacle --noninteractive",
+      "environmentVariables": {
+        "ACCEPT_EULA": "Y",
+        "OCTOPUS__K8STENTACLE__NAMESPACE": "octopus-agent-<agent-name>",
+        "OCTOPUS__K8STENTACLE__PODSERVICEACCOUNTNAME": "octopus-agent-scripts",
+        "OCTOPUS__K8STENTACLE__PODVOLUMECLAIMNAME": "octopus-agent-<agent-name>-pvc",
+        "OCTOPUS__K8STENTACLE__HELMRELEASENAME": "<agent-name>",
+        "OCTOPUS__K8STENTACLE__HELMCHARTVERSION": "2.4.0",
+        "OCTOPUS__K8STENTACLE__DISABLEAUTOPODCLEANUP": "false",
+        "OCTOPUS__K8STENTACLE__DISABLEPODEVENTSINTASKLOG": "false",
+        "OCTOPUS__TENTACLE__LOGLEVEL": "Info",
+        "TentacleHome": "/tmp/k8s-agent-debug-vol",
+        "TentacleApplications": "/tmp/k8s-agent-debug-vol/Applications",
+        "TentaclePollingConnectionCount": "5",
+        "OCTOPUS__K8STENTACLE__ENABLEMETRICSCAPTURE": "false",
+        "OCTOPUS__K8STENTACLE__PERSISTENTVOLUMESIZE": "10Gi",
+        "KUBECONFIG": "<kube-config>",
+        "DefaultLogDirectory": "/tmp/k8s-agent-debug-vol/logs",
+        "BOOTSTRAPRUNNEREXECUTABLEPATH": "/tmp/k8s-agent-debug-vol/bootstrapRunner",
+        "OCTOPUS__K8STENTACLE__PODRESOURCEJSON": "{\"requests\":{\"cpu\":\"25m\",\"memory\":\"100Mi\"}}"
+      }
+    }
+  }
+}

k8s-agent-debug-cluster-config/local-persistent-volume.yaml

@@ -0,0 +1,21 @@
+apiVersion: v1
+kind: PersistentVolume
+metadata:
+  name: local-pv
+spec:
+  capacity:
+    storage: 10Gi
+  accessModes:
+  - ReadWriteMany
+  persistentVolumeReclaimPolicy: Retain
+  storageClassName: local-storage
+  local:
+    path: /k8s-agent-debug-vol
+  nodeAffinity:
+    required:
+      nodeSelectorTerms:
+      - matchExpressions:
+        - key: kubernetes.io/hostname
+          operator: In
+          values:
+          - k8s-agent-debug-cluster-control-plane

k8s-agent-debug-cluster-config/local-storage-class.yaml

@@ -0,0 +1,6 @@
+kind: StorageClass
+apiVersion: storage.k8s.io/v1
+metadata:
+  name: local-storage
+provisioner: kubernetes.io/no-provisioner
+volumeBindingMode: WaitForFirstConsumer

setup-k8s-agent-for-local-debug.sh

@@ -0,0 +1,99 @@
+#!/bin/bash
+
+echo "This script will create a kind cluster configured for debugging the k8s agent locally in Rider"
+echo "NOTE: This has only been tested on MacOS and for agents running as deployment targets."
+echo "Requirements: Docker Desktop, Kind CLI, Go CLI, Rider"
+echo "continue? Y/n"
+
+ans=Y
+read -r ans
+
+if [ -n "$ans" ] && [ "$ans" != "Y" ] && [ "$ans" != "y" ]; then
+  exit 0
+fi
+
+echo ""
+echo ""
+echo "🏗️  - Installing kind cluster with name \"kind-k8s-agent-debug-cluster\""
+kind create cluster --config k8s-agent-debug-cluster-config/k8s-agent-debug-cluster.yaml
+
+if [ $? -ne 0 ]; then
+  echo ""
+  echo ""
+  echo "❗  - Failed to create kind cluster, please check errors above. Aborting."
+  exit -1
+fi
+
+echo "🏗️  - Adding local storage class to kind cluster called \"local-storage\""
+kubectl apply -f k8s-agent-debug-cluster-config/local-storage-class.yaml
+
+if [ $? -ne 0 ]; then
+  echo ""
+  echo ""
+  echo "❗  - Failed to create local storage class. Aborting."
+  exit -1
+fi
+
+echo "🏗️  - Adding local persistent volume to kind cluster"
+kubectl apply -f k8s-agent-debug-cluster-config/local-persistent-volume.yaml
+
+if [ $? -ne 0 ]; then
+  echo "❗  - Failed to create local persistent volume. Aborting."
+  exit -1
+fi
+
+echo "🏗️  - Building bootstrap runner"
+env GOOS=linux go build -C docker/kubernetes-agent-tentacle/bootstrapRunner -ldflags "-s -w" -o "/tmp/k8s-agent-debug-vol/bootstrapRunner"
+
+if [ $? -ne 0 ]; then
+  echo ""
+  echo ""
+  echo "❗  - Failed to build bootstrap runner. Aborting."
+  exit -1
+fi
+
+echo ""
+echo ""
+echo "The cluster is ready! 👌"
+printf "Now generate the k8s agent helm command from your Octopus instance:\n- ADD \"local-storage\" as the storage class for your agent.\n- CHOOSE \"Docker Desktop\" in the DEV dropdown list.\n- RUN the install script against the new kind cluster (called \"kind-k8s-agent-debug-cluster\").\n\nWhen the installation is complete and the agent has successfully completed a health check, continue executing this script!"
+
+while [ -z "$agentName" ]
+do
+  echo ""
+  echo ""
+  echo "❔  - What name did you give your agent?"
+
+  read -r agentName
+done
+
+echo ""
+echo ""
+echo "🏗️  - Scaling down agent \"$agentName\" deployment in cluster"
+kubectl scale --replicas=0 deployment/octopus-agent-tentacle -n "octopus-agent-$agentName"
+echo "🏗️  - Changing the tentacle config to use localhost"
+configMapContents=`kubectl get configmap tentacle-config -n "octopus-agent-$agentName" -o yaml`
+configMapContents="${configMapContents//host\.docker\.internal/localhost}"
+echo "🏗️  - Changing home dir and applications dir to use /tmp/k8s-agent-debug-vol"
+configMapContents="${configMapContents//\/octopus//tmp/k8s-agent-debug-vol}"
+echo "$configMapContents" | kubectl apply -f -
+
+if [ -z "$KUBECONFIG" ]; then
+  kubeConfig=~/.kube/config
+else
+  kubeConfig="$KUBECONFIG"
+fi
+
+echo ""
+echo ""
+echo "🏗️  - Copying launch settings for Octopus.Tentacle project"
+launchSettings=`cat k8s-agent-debug-cluster-config/launchSettings.template.json`
+launchSettings=${launchSettings//\<agent-name\>/"$agentName"}
+launchSettings=${launchSettings//\<kube-config\>/"$kubeConfig"}
+echo "$launchSettings" > "./source/Octopus.Tentacle/Properties/launchSettings.json"
+
+echo ""
+echo ""
+echo "Done! 🚀"
+echo ""
+echo "You can now run/debug the Agent using the launch settings in Octopus.Tentacle/Properties/launchSettings.json."
+echo "Check the run configuration in Rider to ensure that you're running it with the correct .net Framework version (net8.0)"

source/Octopus.Tentacle/Diagnostics/OctopusLogsDirectoryRenderer.cs

@@ -5,13 +5,14 @@
 using System.Text;
 using NLog;
 using NLog.LayoutRenderers;
+using Octopus.Tentacle.Variables;
 
 namespace Octopus.Tentacle.Diagnostics
 {
     [LayoutRenderer("octopusLogsDirectory")]
     public class OctopusLogsDirectoryRenderer : LayoutRenderer
     {
-        public static readonly string DefaultLogsDirectory =
+        public static readonly string DefaultLogsDirectory = Environment.GetEnvironmentVariable(EnvironmentVariables.DefaultLogDirectory) ??
             Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), Path.Combine("Octopus", "Logs"));
 
         public static readonly HashSet<string> History = new HashSet<string>();

source/Octopus.Tentacle/Kubernetes/KubernetesPhysicalFileSystem.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using Octopus.Diagnostics;
 using Octopus.Tentacle.Util;
+using Octopus.Tentacle.Variables;
 
 namespace Octopus.Tentacle.Kubernetes
 {
@@ -13,7 +14,7 @@ public class KubernetesPhysicalFileSystem : OctopusPhysicalFileSystem
         // Set like this for now because we don't have a way to get the home directory from the provider without requiring ourselves
         // DI can be painful when circular dependencies happen with constructed classes :sad-panda:
         // When we can get an Injectable KubernetesConfiguration, we can remove this, alternatively, we can pull apart the configuration stores into different implementations
-        const string HomeDir = "/octopus";
+        readonly string HomeDir = Environment.GetEnvironmentVariable(EnvironmentVariables.TentacleHome) ?? "/octopus";
 
         public KubernetesPhysicalFileSystem(IKubernetesDirectoryInformationProvider directoryInformationProvider,
             ISystemLog log) : base(log)

source/Octopus.Tentacle/Kubernetes/LocalMachineKubernetesClientConfigProvider.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using k8s;
 
 namespace Octopus.Tentacle.Kubernetes
@@ -9,6 +10,20 @@ public KubernetesClientConfiguration Get()
         {
 #if DEBUG
             var kubeConfigEnvVar = Environment.GetEnvironmentVariable("KUBECONFIG");
+            if (kubeConfigEnvVar != null && !Path.IsPathRooted(kubeConfigEnvVar))
+            {
+                // Path.GetFullPath doesn't work with ~, so we need to expand it manually
+                if (kubeConfigEnvVar.StartsWith("~"))
+                {
+                    kubeConfigEnvVar = kubeConfigEnvVar
+                        .Replace("~", Environment.GetFolderPath(Environment.SpecialFolder.UserProfile))
+                        .Replace("//", "/");
+                }
+                else
+                {
+                    kubeConfigEnvVar = Path.GetFullPath(kubeConfigEnvVar);
+                }
+            }
             return KubernetesClientConfiguration.BuildConfigFromConfigFile(kubeConfigEnvVar);
 #else
             throw new NotSupportedException("Local machine configuration is only supported when debugging.");

source/Octopus.Tentacle/Variables/EnvironmentVariables.cs

@@ -27,5 +27,6 @@ public static class EnvironmentVariables
         public const string NfsWatchdogDirectory = "watchdog_directory";
         public static string TentacleUseTcpNoDelay = "TentacleUseTcpNoDelay";
         public static string TentacleUseAsyncListener = "TentacleUseAsyncListener";
+        public static string DefaultLogDirectory = "DefaultLogDirectory";
     }
 }