Add telepresence script (#1135)

Author: liam-mackie

source/Octopus.Tentacle/Kubernetes/LocalMachineKubernetesClientConfigProvider.cs

@@ -1,14 +1,24 @@
 using System;
 using System.IO;
+using System.Security.Cryptography.X509Certificates;
 using k8s;
+using k8s.Authentication;
 
 namespace Octopus.Tentacle.Kubernetes
 {
     class LocalMachineKubernetesClientConfigProvider : IKubernetesClientConfigProvider
     {
+        const string ServiceAccountTokenKeyFileName = "token";
+        const string ServiceAccountRootCAKeyFileName = "ca.crt";
+
         public KubernetesClientConfiguration Get()
         {
 #if DEBUG
+            var telepresenceRoot = Environment.GetEnvironmentVariable("TELEPRESENCE_ROOT");
+            if (!string.IsNullOrEmpty(telepresenceRoot))
+            {
+                return GetTelepresenceConfig(telepresenceRoot);
+            }
             var kubeConfigEnvVar = Environment.GetEnvironmentVariable("KUBECONFIG");
             if (kubeConfigEnvVar != null && !Path.IsPathRooted(kubeConfigEnvVar))
             {
@@ -29,5 +39,45 @@ public KubernetesClientConfiguration Get()
             throw new NotSupportedException("Local machine configuration is only supported when debugging.");
 #endif
         }
+
+        KubernetesClientConfiguration GetTelepresenceConfig(string telepresenceRoot)
+        {
+            var serviceAccountPath =
+                Path.Combine(new string[]
+                {
+                    $"{telepresenceRoot}", "var", "run", "secrets", "kubernetes.io", "serviceaccount",
+                });
+            var rootCAFile = Path.Combine(serviceAccountPath, ServiceAccountRootCAKeyFileName);
+            var host = Environment.GetEnvironmentVariable("KUBERNETES_SERVICE_HOST");
+            var port = Environment.GetEnvironmentVariable("KUBERNETES_SERVICE_PORT");
+            if (string.IsNullOrEmpty(host))
+            {
+                host = "kubernetes.default.svc";
+            }
+
+            if (string.IsNullOrEmpty(port))
+            {
+                port = "443";
+            }
+
+            X509Certificate2Collection certificates = new X509Certificate2Collection();
+            certificates.Import(rootCAFile);
+            
+            var result = new KubernetesClientConfiguration
+            {
+                Host = new UriBuilder("https", host, Convert.ToInt32(port)).ToString(),
+                TokenProvider = new TokenFileAuth(Path.Combine(serviceAccountPath, ServiceAccountTokenKeyFileName)),
+                SslCaCerts = certificates,
+            };
+            
+            var namespaceVar = Environment.GetEnvironmentVariable("OCTOPUS__K8STENTACLE__NAMESPACE");
+
+            if (!string.IsNullOrEmpty(namespaceVar))
+            {
+                result.Namespace = namespaceVar;
+            }
+
+            return result;
+        }
     }
 }

telepresence-config/launchSettings.template.json

@@ -0,0 +1,21 @@
+{
+  "profiles": {
+    "Telepresence - <deployment-name>": {
+      "commandName": "Project",
+      "commandLineArgs": "agent --instance Tentacle --noninteractive",
+      "environmentVariables": {
+        "TentacleHome": "<telepresence-root>/octopus",
+        "TentacleApplications": "<telepresence-root>/octopus/Applications",
+        "DefaultLogDirectory": "<telepresence-root>/octopus/logs",
+        "BOOTSTRAPRUNNEREXECUTABLEPATH": "/tmp/k8s-agent-debug-vol/bootstrapRunner",
+        "TELEPRESENCE_ROOT": "<telepresence-root>",
+        "OCTOPUS_HOME": "<telepresence-root>",
+        "OCTOPUS_CONTRIBUTE_ENV_SETTINGS": "true"
+      },
+      "dotnetRunMessages": true,
+      "workingDirectory": "<telepresence-root>",
+      "launchBrowser": false,
+      "nativeDebugging": false
+    }
+  }
+}