# LookupMachineImage

A machine image whose AMI ID will be searched using DescribeImages.

The most recent, available, launchable image matching the given filter
criteria will be used. Looking up AMIs may take a long time; specify
as many filter criteria as possible to narrow down the search.

The AMI selected will be cached in `cdk.context.json` and the same value
will be used on future runs. To refresh the AMI lookup, you will have to
evict the value from the cache using the `cdk context` command. See
https://docs.aws.amazon.com/cdk/latest/guide/context.html for more information.
If `props.additionalCacheKey` is set, the context key uses that value as a discriminator
rather than the cached value being global across all lookups.

Extends: LookupMachineImage
Implements: IMachineImage
Superclass of: NatInstanceImage

- Source: [`aws-ec2/lib/machine-image/machine-image.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-ec2/lib/machine-image/machine-image.ts#L691)

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_ec2 as ec2 } from 'aws-cdk-lib';

declare const userData: ec2.UserData;
const lookupMachineImage = new ec2.LookupMachineImage({
  name: 'name',

  // the properties below are optional
  additionalCacheKey: 'additionalCacheKey',
  filters: {
    filtersKey: ['filters'],
  },
  owners: ['owners'],
  userData: userData,
  windows: false,
});
```

## Initializer

```ts
new LookupMachineImage(props: LookupMachineImageProps)
```

## Methods

- `getImage(scope: Construct): MachineImageConfig` — Return the correct image.