Appendix E: Image Handler Function Environmental Variables
Most settings and customizations to the Serverless Image Handler solution can be made by editing and updating the environment variables associated with the image handler AWS Lambda function.
The image handler function can be found in the AWS Management Console using one of the following methods:
-
In the Lambda Management Console, the image handler function is listed with the following naming convention:
<StackName>-<ImageHandlerFunction>-<UniqueId> -
In the AWS CloudFormation Management Console, the image handler function is listed under the Resources tab of your deployed stack with a Logical ID of
ImageHandlerFunction.
After opening the Lambda function, scroll down to the Environment variables section. Use the following key-value pairs to customize the solutions settings:
| Parameter | Value Type | Description |
|---|---|---|
| CorsEnabled | Yes/No |
Indicates whether to return an Access-Control-Allow-Origin header with the image handler API response. |
| CorsOrigin | String |
This value is returned by the API in the Access-Control-Allow-Origin header. A star
(*) value supports any origin. We recommend specifying a specific origin (e.g.
http://example.domain) to restrict cross-site access to your API.
This value is ignored if CorsEnabled is set to |
| RewriteMatchPattern | Regex |
By default, this parameter is empty. Contains a JavaScript-compatible regular expression for matching custom image requests using the rewrite function. |
| RewriteReplacePattern | String |
By default, this parameter is empty. Contains a substitution string for custom image requests using the rewrite function. |
| SourceBuckets | String/Regex |
The S3 bucket (or buckets) in your account that contains the original images. If providing multiple buckets, separate them by commas. Regular expression can be used as bucket prefix for multiple buckets. |
| AutoWebP | Yes/No |
Choose whether to automatically accept webp image formats. |
