Fix 018-ecs-ec2: heredoc 'EOF' → EOF for variable expansion. Add 000-prereqs-directory CFN stack.

018: user data had literal $CLUSTER_NAME instead of the actual cluster name.
     Single-quoted heredoc prevented variable expansion. Passes locally.
000-prereqs-directory: Simple AD for WorkSpaces tutorials. Deployed.

Author: mwunderl

tuts/000-prereqs-directory/cfn-prereqs-directory.yaml

@@ -0,0 +1,39 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Description: 'Prereq: Simple AD directory for WorkSpaces tutorials. Uses default VPC.'
+
+Parameters:
+  DirectoryName:
+    Type: String
+    Default: corp.example.com
+  DirectorySize:
+    Type: String
+    Default: Small
+    AllowedValues: [Small, Large]
+  VpcId:
+    Type: AWS::EC2::VPC::Id
+    Description: VPC for the directory (use default VPC)
+  SubnetId1:
+    Type: AWS::EC2::Subnet::Id
+    Description: First subnet (must be in a different AZ from SubnetId2)
+  SubnetId2:
+    Type: AWS::EC2::Subnet::Id
+    Description: Second subnet (must be in a different AZ from SubnetId1)
+
+Resources:
+  Directory:
+    Type: AWS::DirectoryService::SimpleAD
+    Properties:
+      Name: !Ref DirectoryName
+      Password: 'TutorialPass123!'
+      Size: !Ref DirectorySize
+      VpcSettings:
+        VpcId: !Ref VpcId
+        SubnetIds:
+          - !Ref SubnetId1
+          - !Ref SubnetId2
+
+Outputs:
+  DirectoryId:
+    Value: !Ref Directory
+    Export:
+      Name: !Sub '${AWS::StackName}-DirectoryId'

tuts/018-ecs-ec2/ecs-ec2-getting-started.sh

@@ -343,7 +343,7 @@ launch_container_instance() {
     log "Launching ECS container instance..."
 
     # Create user data script
-    cat > ecs-user-data.sh << 'EOF'
+    cat > ecs-user-data.sh << EOF
 #!/bin/bash
 echo ECS_CLUSTER=$CLUSTER_NAME >> /etc/ecs/ecs.config
 EOF