support referencing an existing eks cluster

.gitignore

@@ -1,2 +1,3 @@
 node_modules/
-target/
+target/
+values.yaml

README.md

@@ -36,8 +36,22 @@ When executed in the Wing Simulator, the workload is started within a local Dock
 
 ### `tf-aws`
 
-On AWS, an EKS cluster is provisioned and the workload is deployed through Helm into the Kubernetes
-cluster.
+By default an EKS cluster is provisioned and the workload is deployed through Helm into the
+Kubernetes cluster.
+
+To use an existing EKS cluster, the following platform values are required:
+
+* `eks.cluster_name` - the name of the cluster
+* `eks.endpoint` - the url of the kuberenets api endpoint of the cluster
+* `eks.certificate` - the certificate authority of this cluster.
+
+The `eks-values.sh` script can be used to query the values for an existing cluster and create a
+values file:
+
+```sh
+$ ./eks-values.sh CLUSTER-NAME > values.yaml
+$ wing compile -t tf-aws --values ./values.yaml main.w
+```
 
 ## TODO
 
@@ -46,7 +60,7 @@ See [Captain's Log](https://winglang.slack.com/archives/C047QFSUL5R/p16968681568
 - [x] EKS as a singleton
 - [ ] Add support for local Dockerfiles (currently only images from Docker Hub are supported), this
       includes publishing into an ECR.
-- [ ] Reference existing EKS repository.
+- [x] Reference existing EKS repository.
 - [ ] Use a `cloud.Redis` database
 - [ ] Implement `cloud.Service` using containers.
 - [ ] Deploy multiple workloads (maybe guestbook?)

eks-values.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+if [ -z "$1" ]; then
+  echo "Usage: $0 <cluster-name>"
+  exit 1
+fi
+
+export cluster_name=$1
+export cluster_endpoint=$(aws eks describe-cluster --name $cluster_name --query "cluster.endpoint")
+export cluster_certificate=$(aws eks describe-cluster --name $cluster_name --query "cluster.certificateAuthority.data")
+
+cat << EOF
+eks.cluster_name: $cluster_name
+eks.endpoint: $cluster_endpoint
+eks.certificate: $cluster_certificate
+EOF

package.json

@@ -1,10 +1,10 @@
 {
   "name": "wing-containers",
   "version": "1.0.0",
-  "description": "",
+  "description": "A containers library for Wing",
   "main": "index.js",
   "scripts": {
-    "build": "wing test test/containers.test.w"
+    "build": "wing test test/*.test.w"
   },
   "author": {
     "email": "[email protected]",
@@ -17,6 +17,6 @@
     "@cdktf/provider-kubernetes": "^9.0.0",
     "cdk8s-plus-27": "^2.7.33",
     "cdktf": "^0.18.2",
-    "winglang": "^0.36.1"
+    "winglang": "^0.37.1"
   }
 }

sim/util.js

@@ -0,0 +1,18 @@
+const child_process = require("child_process");
+
+exports.shell = async function (command, args, cwd) {
+  return new Promise((resolve, reject) => {
+    child_process.execFile(command, args, { cwd }, (error, stdout, stderr) => {
+      if (error) {
+        console.error(stderr);
+        return reject(error);
+      }
+
+      return resolve(stdout ? stdout : stderr);
+    });
+  });
+};
+
+exports.entrypointDir = function (scope) {
+  return scope.node.root.entrypointDir;
+};

test/containers.test.w

@@ -7,7 +7,7 @@ let hello = new containers.Workload(
   image: "paulbouwer/hello-kubernetes:1",
   port: 8080,
   readiness: "/",
-  replicas: 3,
+  replicas: 2,
   env: {
     "MESSAGE" => message,
   },
@@ -18,7 +18,7 @@ new containers.Workload(
   image: "hashicorp/http-echo",
   port: 5678,
   public: true,
-  replicas: 20,
+  replicas: 2,
   args: ["-text=hello1234"],
 ) as "http-echo";
 

test/simple.test.w

@@ -0,0 +1,9 @@
+bring "../containers.w" as containers;
+
+new containers.Workload(
+  image: "hashicorp/http-echo",
+  port: 5678,
+  public: true,
+  replicas: 2,
+  args: ["-text=bang_bang"],
+);

test/values.test.w

@@ -1,2 +1,6 @@
 bring "../tf-aws/values.w" as values;
-values.get("foo");
+bring util;
+
+if let x = values.tryGet("foo") {
+  log(x);
+}

tf-aws/eks.w

@@ -56,12 +56,32 @@ class Cluster impl ICluster {
 
   /** singleton */
   pub static getOrCreate(scope: std.IResource): ICluster {
-    // values.get("foo");
-
     let stack = cdktf.TerraformStack.of(scope);
     let uid = "WingEksCluster";
-    let existing: Cluster? = unsafeCast(stack.node.tryFindChild(uid));
-    return existing ?? new Cluster() as uid in stack;
+    let existing: ICluster? = unsafeCast(stack.node.tryFindChild(uid));
+
+    let newCluster = (): ICluster => {
+      if let attrs = Cluster.tryGetClusterAttributes() {
+        return new ClusterRef(attrs) as uid in stack;
+      } else {
+        return new Cluster() as uid in stack;
+      }
+    };
+
+    return existing ?? newCluster();
+  }
+
+  static tryGetClusterAttributes(): ClusterAttributes? {
+    if !values.has("eks.cluster_name") {
+      return nil;
+    }
+
+    return ClusterAttributes {
+      name: values.get("eks.cluster_name"),
+      certificate: values.get("eks.certificate"),
+      endpoint: values.get("eks.endpoint"),
+    };
+
   }
 
   _attributes: ClusterAttributes;

test/util.js → tf-aws/util.js

@@ -1,27 +1,9 @@
-const child_process = require("child_process");
 const cdk8s = require('cdk8s');
 const fs = require('fs');
 const path = require('path');
 const wingsdk = require('@winglang/sdk');
 const crypto = require('crypto');
 
-exports.shell = async function (command, args, cwd) {
-  return new Promise((resolve, reject) => {
-    child_process.execFile(command, args, { cwd }, (error, stdout, stderr) => {
-      if (error) {
-        console.error(stderr);
-        return reject(error);
-      }
-
-      return resolve(stdout ? stdout : stderr);
-    });
-  });
-};
-
-exports.entrypointDir = function (scope) {
-  return scope.node.root.entrypointDir;
-};
-
 exports.toHelmChart = function(chart) {
   const app = cdk8s.App.of(chart);
   const wingdir = wingsdk.core.App.of(chart).workdir;