# FleetProps

Construction properties of a CodeBuild Fleet.

Extends: FleetProps
Used as props by: Fleet

- Source: [`aws-codebuild/lib/fleet.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0/packages/aws-cdk-lib/aws-codebuild/lib/fleet.ts#L18)
- Type last changed: v2.219.0 · 1 Oct 2025

## Example

```ts
import { Size } from 'aws-cdk-lib';

const fleet = new codebuild.Fleet(this, 'MyFleet', {
  baseCapacity: 1,
  computeType: codebuild.FleetComputeType.CUSTOM_INSTANCE_TYPE,
  environmentType: codebuild.EnvironmentType.LINUX_CONTAINER,
  computeConfiguration: {
    instanceType: ec2.InstanceType.of(ec2.InstanceClass.T3, ec2.InstanceSize.MEDIUM),
    // By default, 64 GiB of disk space is included. Any value optionally
    // specified here is _incremental_ on top of the included disk space.
    disk: Size.gibibytes(10),
  },
});
```

## Properties

- `baseCapacity`: number (required) — The number of machines allocated to the compute fleet. Defines the number of builds that can run in parallel.

  Minimum value of 1.

- `computeConfiguration`: [ComputeConfiguration](/cdk/api/v2/docs/aws-cdk-lib.aws_codebuild.ComputeConfiguration.html) — The compute configuration of the compute fleet.

  **Default:** do not specify compute configuration

  This is only permitted if `computeType` is set to ATTRIBUTE_BASED or
  CUSTOM_INSTANCE_TYPE. In such cases, this is required.

- `computeType`: [FleetComputeType](/cdk/api/v2/docs/aws-cdk-lib.aws_codebuild.FleetComputeType.html) (required) — The instance type of the compute fleet.

- `environmentType`: [EnvironmentType](/cdk/api/v2/docs/aws-cdk-lib.aws_codebuild.EnvironmentType.html) (required) — The build environment (operating system/architecture/accelerator) type made available to projects using this fleet.

- `fleetName`: string — The name of the Fleet.

  **Default:** CloudFormation generated name

- `overflowBehavior`: [FleetOverflowBehavior](/cdk/api/v2/docs/aws-cdk-lib.aws_codebuild.FleetOverflowBehavior.html) — The compute fleet overflow behavior.

  **Default:** undefined - AWS CodeBuild default behavior is QUEUE

  For overflow behavior `QUEUE`, overflow builds need to wait on the existing fleet instances to become available.

  For overflow behavior `ON_DEMAND`, overflow builds run on CodeBuild on-demand.

- `role`: [IRole](/cdk/api/v2/docs/aws-cdk-lib.aws_iam.IRole.html) — Service Role assumed by Fleet instances.

  **Default:** A role will be created if any permissions are granted

  This Role is not used by Project builds running on Fleet instances; Project
  builds assume the `role` on Project instead.

- `securityGroups`: [ISecurityGroup](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.ISecurityGroup.html)[] — What security groups to associate with the fleet's network interfaces. If none are provided, one will be created automatically.

  **Default:** A security group will be automatically created.

  Only used if `vpc` is supplied.

- `subnetSelection`: [SubnetSelection](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.SubnetSelection.html) — Where to place the network interfaces within the VPC.

  **Default:** private subnets if available else public subnets

  To access AWS services, your fleet needs to be in one of the following types of subnets:

  1. Subnets with access to the internet (of type PRIVATE_WITH_EGRESS).
  2. Private subnets unconnected to the internet, but with [VPC endpoints](https://docs.aws.amazon.com/codebuild/latest/userguide/use-vpc-endpoints-with-codebuild.html) for the necessary services.

  If you don't specify a subnet selection, the default behavior is to use PRIVATE_WITH_EGRESS subnets first if they exist,
  then PRIVATE_WITHOUT_EGRESS, and finally PUBLIC subnets. If your VPC doesn't have PRIVATE_WITH_EGRESS subnets but you need
  AWS service access, add VPC Endpoints to your private subnets.

- `vpc`: [IVpc](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.IVpc.html) — VPC network to place fleet instance network interfaces.

  **Default:** No VPC is specified.

  Specify this if the fleet needs to access resources in a VPC.