Fjall Docs — Deploy Production-Ready AWS Infrastructure in Minutes

Overview

NetworkFactory creates VPC and networking infrastructure on AWS. Fjall configures networking automatically when you create an application. Use NetworkFactory directly when you need custom networking.

Automatic Networking

When you create an application, Fjall automatically provisions:

VPC Configuration

CIDR blocks: Managed by IPAM
Availability zones: Multi-AZ by default
Subnets: Public and private subnets per AZ
NAT gateways: For private subnet internet access
VPC endpoints: For AWS service access

Security Groups

Automatic rules: Based on resource connections
Least privilege: Only required ports opened
Dynamic updates: As resources are added

Load Balancers

Application Load Balancer: For ECS services
Target groups: Automatic health checks
SSL termination: With ACM certificates

Current Implementation

Through App Class

const app = App.getApp("myapp");
// VPC is automatically created and configured

Through Compute Factory

app.addCompute(
  ComputeFactory.build("api", {
    type: "ecs",
    cluster: {
      domain: "api.example.com",
      domainConfig: { certificateArn: "arn:aws:acm:..." },
    },
    services: [
      {
        name: "api",
        capacityProvider: "FARGATE",
        containers: [{ port: 3000 }],
      },
    ],
    // ALB and target groups created automatically
  }),
);

Through Database Factory

app.addDatabase(
  DatabaseFactory.build("MyDB", {
    type: "Aurora",
    databaseName: "MyDatabase",
    // Security groups and subnet groups configured automatically
  }),
);

Connection Management

Declare connections on a service and Fjall wires the security group rules:

const storage = app.addStorage(...);

const web = app.addCompute(
  ComputeFactory.build("web", {
    type: "ecs",
    services: [
      {
        name: "web",
        capacityProvider: "FARGATE",
        containers: [{ port: 3000 }],
        connections: [storage], // Security group rules added automatically
      },
    ],
  }),
);

NetworkFactory Usage

Basic Usage

import { App, NetworkFactory } from "@fjall/components-infrastructure";

const app = App.getApp("myapp");

const network = app.addNetwork(
  NetworkFactory.build("MainVPC", {
    maxAzs: 2,
  }),
);

Full Configuration

const network = app.addNetwork(
  NetworkFactory.build("MainVPC", {
    vpcName: "production-vpc",
    maxAzs: 3,
    cidrMask: 24,
    natGateways: {
      count: 2, // One per AZ for HA
    },
    flowLogs: {
      destination: "cloudwatch",
      retentionDays: 30,
      trafficType: "ALL",
    },
    vpcEndpoints: {
      gateway: { s3: true, dynamodb: true },
      interface: { ecr: true, secretsManager: true, ssm: true },
    },
  }),
);

Parameters

Parameter	Type	Description	Default
`vpcName`	string	Custom VPC name	App name
`maxAzs`	number	Number of availability zones	`2`
`cidrMask`	number	Subnet CIDR mask	`24`
`natGateways`	`{ count: number }` or `false`	NAT gateway config, or `false` to disable	`{ count: 1 }`
`flowLogs`	`{ destination, retentionDays?, trafficType? }` or `false`	Flow logs config	Disabled
`flowLogs.destination`	`"cloudwatch" \| "s3"`	Log destination	-
`flowLogs.retentionDays`	number	CloudWatch log retention (days)	`14`
`flowLogs.trafficType`	`"ALL" \| "ACCEPT" \| "REJECT"`	Traffic to log	`"ALL"`
`vpcEndpoints`	object or `false`	VPC endpoint configuration	None
`vpcEndpoints.gateway`	`{ s3?: boolean, dynamodb?: boolean }`	Gateway endpoints	`{}`
`vpcEndpoints.interface`	`{ ecr?, secretsManager?, kms?, ssm?, sts?, cloudwatchLogs? }`	Interface endpoints	`{}`
`subnets`	object	Custom subnet configuration	Auto
`transitGateway`	`{ id: string }`	Transit Gateway attachment	None

Disabling NAT Gateways

For cost savings in development:

const network = app.addNetwork(
  NetworkFactory.build("DevVPC", {
    natGateways: false, // No NAT gateways (public subnets only)
  }),
);

VPC Endpoints for Private Access

Reduce data transfer costs and improve security. Gateway endpoints support s3 and dynamodb. Interface endpoints support ecr, secretsManager, kms, ssm, sts, and cloudwatchLogs:

const network = app.addNetwork(
  NetworkFactory.build("SecureVPC", {
    vpcEndpoints: {
      gateway: { s3: true, dynamodb: true },
      interface: {
        ecr: true,
        secretsManager: true,
        kms: true,
        ssm: true,
        sts: true,
        cloudwatchLogs: true,
      },
    },
  }),
);

Transit Gateway Integration

Connect VPCs across accounts:

const network = app.addNetwork(
  NetworkFactory.build("ConnectedVPC", {
    transitGateway: {
      id: "tgw-0123456789abcdef0",
    },
  }),
);

Best Practices

Let Fjall manage networking - Automatic configuration handles most use cases
Use IPAM - Prevents CIDR conflicts across accounts
Multi-AZ deployment - Enabled by default for resilience
Private subnets - Databases always in private subnets
VPC endpoints - Reduces data transfer costs

Next Steps

Compute Factory

Deploy ECS and Lambda applications behind the VPC.

Database Factory

Provision Aurora, RDS, and DynamoDB in private subnets.

Storage Factory

Create S3 buckets with VPC gateway endpoint access.

Standard Pattern

Compose a full application with networking included.

Factory Patterns

Application Patterns

Architecture Patterns

Network Factory

Overview

Automatic Networking

VPC Configuration

Security Groups

Load Balancers

Current Implementation

Through App Class

Through Compute Factory

Through Database Factory

Connection Management

NetworkFactory Usage

Basic Usage

Full Configuration

Parameters

Disabling NAT Gateways

VPC Endpoints for Private Access

Transit Gateway Integration

Best Practices

Next Steps

Compute Factory

Database Factory

Storage Factory

Standard Pattern

​Overview

​Automatic Networking

​VPC Configuration

​Security Groups

​Load Balancers

​Current Implementation

​Through App Class

​Through Compute Factory

​Through Database Factory

​Connection Management

​NetworkFactory Usage

​Basic Usage

​Full Configuration

​Parameters

​Disabling NAT Gateways

​VPC Endpoints for Private Access

​Transit Gateway Integration

​Best Practices

​Next Steps

Compute Factory

Database Factory

Storage Factory

Standard Pattern

Overview

Automatic Networking

VPC Configuration

Security Groups

Load Balancers

Current Implementation

Through App Class

Through Compute Factory

Through Database Factory

Connection Management

NetworkFactory Usage

Basic Usage

Full Configuration

Parameters

Disabling NAT Gateways

VPC Endpoints for Private Access

Transit Gateway Integration

Best Practices

Next Steps