One-page summary — important extracts & flow

1) Parameters (inputs)

• VpcCIDR — VPC IP range (default 10.0.0.0/16)

• Subnet1CIDR — Subnet 1 range (default 10.0.1.0/24) — AZ A

• Subnet2CIDR — Subnet 2 range (default 10.0.2.0/24) — AZ B

• ImageUrl — ECR image URI to run in ECS (e.g. 123456789012.dkr.ecr.<region>.amazonaws.com/documentportal:latest)

2) Resources (what the template creates — in execution order / dependency flow)

1. ECR repository

   • MyECRRepository (AWS::ECR::Repository)

   • Stores container images (documentportal). ScanOnPush: true, ImageTagMutability: MUTABLE.

2. Network

   • MyVPC (AWS::EC2::VPC) — CidrBlock: !Ref VpcCIDR

   • Subnet1 (AWS::EC2::Subnet) — CidrBlock: !Ref Subnet1CIDR, AZ = first AZ, MapPublicIpOnLaunch: true

   • Subnet2 (AWS::EC2::Subnet) — CidrBlock: !Ref Subnet2CIDR, AZ = second AZ, MapPublicIpOnLaunch: true

   • InternetGateway (AWS::EC2::InternetGateway)

   • AttachGateway (AWS::EC2::VPCGatewayAttachment) — attaches IGW to MyVPC

   • RouteTable (AWS::EC2::RouteTable) — for MyVPC

   • PublicRoute (AWS::EC2::Route) — 0.0.0.0/0 → InternetGateway (DependsOn AttachGateway)

   • RouteAssoc1 & RouteAssoc2 — associate route table to Subnet1 and Subnet2
     Result: both subnets are public and have internet routing.

3. ECS core

   • ECSCluster (AWS::ECS::Cluster) — document-portal-cluster

4. IAM / Roles

   • ECSExecutionRole (AWS::IAM::Role) — ecsTaskExecutionRole

     • AssumeRole for ecs-tasks.amazonaws.com

     • Inline policy grants:

       • CloudWatch Logs: CreateLogGroup, CreateLogStream, PutLogEvents (Resource "*")

       • Secrets Manager: GetSecretValue (Resource "*")

     • Note: currently broad — recommend using managed policy AmazonECSTaskExecutionRolePolicy + scoped secret/log ARNs.

5. Security

   • ECSSecurityGroup (AWS::EC2::SecurityGroup)

     • In MyVPC

     • Ingress: tcp 8080 from 0.0.0.0/0 (public)

6. Task Definition

   • ECSTaskDefinition (AWS::ECS::TaskDefinition)

     • Family: documentportaltd

     • CPU: 1024 (1 vCPU), Memory: 8192 (8GB)

     • NetworkMode: awsvpc, RequiresCompatibilities: FARGATE

     • ExecutionRoleArn: !GetAtt ECSExecutionRole.Arn

     • Container:

       • Image: !Ref ImageUrl

       • PortMappings: ContainerPort 8080

       • Environment: LANGCHAIN_PROJECT=DOCUMENT PORTAL

       • Secrets: multiple ValueFrom secret ARNs (hardcoded in us-east-1)

       • LogConfiguration: awslogs → group /ecs/documentportal, region = stack region, stream prefix ecs

7. Service

   • ECSService (AWS::ECS::Service)

     • DependsOn: AttachGateway

     • LaunchType: FARGATE

     • DesiredCount: 1

     • NetworkConfiguration (awsvpc):

       • AssignPublicIp: ENABLED

       • Subnets: Subnet1, Subnet2

       • SecurityGroups: ECSSecurityGroup

     • TaskDefinition: !Ref ECSTaskDefinition

8. Outputs

   • ECSClusterName → cluster logical name

   • TaskDefinitionArn → task definition ARN

3) Logical flow / runtime behavior

• On stack create: VPC & subnets -> IGW & routes -> ECR repo -> IAM role -> ECS cluster -> task definition -> ECS service.

• Service launches Fargate task(s). Because awsvpc + AssignPublicIp: ENABLED, each task gets an ENI and a public IP in either Subnet1 or Subnet2.

• Tasks pull the container image from the ImageUrl. Execution role must permit image pull (ECR) + secrets read + logs write.

• At task start, ECS fetches Secrets Manager secrets (from the ARNs) and injects them as environment variables. Container logs go to CloudWatch Logs under /ecs/documentportal.

4) Immediate risks / important issues to fix

1. Public exposure

   • AssignPublicIp: ENABLED + SG allowing 0.0.0.0/0:8080 → tasks publicly reachable.

   • Recommendation: use an ALB in public subnets and set AssignPublicIp: DISABLED, keep tasks in private subnets. ALB handles TLS and public traffic.

2. Broad IAM permissions

   • Execution role uses wildcard Resource: "*". Replace with:

     • managed policy AmazonECSTaskExecutionRolePolicy (for ECR + logs) and

     • a scoped inline policy for specific Secrets Manager ARNs (and KMS Decrypt if needed).

3. Secrets region mismatch

   • Secrets ARNs point to us-east-1. If stack runs in another region, either:

     • move/mirror secrets to same region or

     • allow cross-region secret access (more complexity). Best: keep secrets in same region.

4. No Task Role

   • No TaskRoleArn present. If your app must call AWS services (S3, DynamoDB, SQS), create a separate Task Role with least privileges and attach via TaskRoleArn in TaskDefinition.

5. Scaling & HA

   • DesiredCount: 1 — single task. For high availability use >=2 across AZs or define ECS Service Auto Scaling (Application Auto Scaling).

6. Logging & retention

   • Consider creating CloudWatch LogGroup in template with RetentionInDays and scope logs permissions to that ARN.

5) Production hardening checklist (apply before production)

• Put tasks in private subnets. Use ALB in public subnets → ALB front-end, tasks private.

• Change AssignPublicIp to DISABLED.

• Create ALB + TargetGroup (port 8080), register ECS Service with ALB.

• Replace wildcard IAM policies with:

  • ManagedPolicyArns: AmazonECSTaskExecutionRolePolicy

  • Scoped secretsmanager:GetSecretValue to specific secret ARNs

  • Add ecr:* and kms:Decrypt as needed (scoped)

• Add TaskRole for runtime AWS API access (not the execution role).

• Increase DesiredCount and add AutoScaling policies (scale on CPU/memory or custom metrics).

• Configure health checks and healthCheckGracePeriodSeconds.

• Parameterize secret ARNs or use Mappings to handle regions/accounts.

• Create CloudWatch LogGroup resource with retention and scope logs permissions.

• Harden security group: only allow ALB SG → Task SG, remove 0.0.0.0/0 unless necessary.

6) Quick example of the safer network pattern (conceptual)

• Public subnets: ALB (internet-facing)

• Private subnets: ECS tasks (no public IP)

• IGW + Route Tables: public subnets route to IGW; private subnets route to NAT (if outbound internet needed)

• Security groups:

  • ALB SG: allow 80/443 from 0.0.0.0/0

  • Task SG: allow port 8080 from ALB SG only

7) Key values to double-check in your template

• ImageUrl — correct ECR URI and region

• Secrets ARNs — region & account match your cluster

• CPU/Memory combo validity for Fargate

• AssignPublicIp — do you need public IP per task?

• Execution role policies and missing TaskRoleArn