aws-diagram

You are generating an AWS architecture diagram. Produce clear, readable diagrams that show the request/data flow through the system.

Process

1. Determine the source:
   • If $ARGUMENTS contains "from-iac": scan the repo for IaC files (CDK, Terraform, CloudFormation, SAM) and reverse-engineer the architecture
   • Otherwise: use the description from $ARGUMENTS or conversation context
2. Generate a Mermaid diagram (primary) and an ASCII fallback
3. Include a legend for any non-obvious notation

Mermaid Diagram Style

Use graph LR (left-to-right) for request flows, graph TD (top-down) for hierarchical architectures.

Conventions

• Users/Clients: Stadium shape ([User])
• AWS Services: Rectangle [Service Name]
• Databases: Cylinder [(Database)]
• Queues: Parallelogram [/Queue/]
• External Services: Double-bordered [[External API]]
• Subgraphs: Group by VPC, subnet, or logical boundary
• Arrows: Label with protocol/action (e.g., -->|HTTPS|, -->|async|)

Example

graph LR
    User([User]) -->|HTTPS| CF[CloudFront]
    CF -->|HTTPS| ALB[ALB]

    subgraph VPC
        subgraph Public Subnet
            ALB
        end
        subgraph Private Subnet
            ECS[ECS Fargate]
            ECS -->|TCP 5432| RDS[(Aurora PostgreSQL)]
            ECS -->|TCP 6379| Redis[(ElastiCache Redis)]
        end
    end

    ECS -->|HTTPS| S3[S3 Bucket]
    ECS -->|SQS| Queue[/Processing Queue/]
    Queue --> Lambda[Lambda Processor]
    Lambda --> S3

ASCII Fallback

For environments that don't render Mermaid:

┌──────┐     ┌────────────┐     ┌─────┐
│ User │────>│ CloudFront │────>│ ALB │
└──────┘     └────────────┘     └──┬──┘
                                   │
                    ┌──────────────┴──────────────┐
                    │         VPC                  │
                    │  ┌─────────────┐             │
                    │  │ ECS Fargate │──> Aurora   │
                    │  │             │──> Redis    │
                    │  └──────┬──────┘             │
                    └─────────┼────────────────────┘
                              │
                         ┌────┴────┐
                         │   SQS   │──> Lambda ──> S3
                         └─────────┘

From IaC Reverse Engineering

When from-iac is specified:

1. Glob for *.tf, *.ts (CDK), template.yaml (SAM), *.template.json (CFN)
2. Extract resources, their relationships, and networking config
3. Map to diagram nodes and edges
4. Highlight any security concerns (public subnets, open SGs) with a warning marker

Output

Always provide:

1. Mermaid diagram (in a ```mermaid code block)
2. ASCII fallback (in a ``` code block)
3. Flow description (1-2 sentences explaining the request/data path)
4. Notes (any assumptions made, security observations)