AWS Lambda

    • This filter should be configured with the name envoy.filters.http.aws_lambda.

    Attention

    The AWS Lambda filter is currently under active development.

    The HTTP AWS Lambda filter is used to trigger an AWS Lambda function from a standard HTTP request. It supports a few options to control whether to pass through the HTTP request payload as is or to wrap it in a JSON schema.

    If payload_passthrough is set to , then the payload is sent to Lambda without any transformations. Note: This means you lose access to all the HTTP headers in the Lambda function.

    However, if is set to false, then the HTTP request is transformed to a JSON payload with the following schema:

    • rawPath is the HTTP request resource path (including the query string)

    • method is the HTTP request method. For example GET, PUT, etc.

    • headers are the HTTP request headers. If multiple headers share the same name, their values are coalesced into a single comma-separated value.

    • queryStringParameters are the HTTP request query string parameters. If multiple parameters share the same name, the last one wins. That is, parameters are _not_ coalesced into a single value if they share the same key name.

    • body the body of the HTTP request is base64-encoded by the filter if the content-type header exists and is _not_ one of the following:

    Otherwise, the body of HTTP request is added to the JSON payload as is.

    On the other end, the response of the Lambda function must conform to the following schema:

    1. {
    2.     "statusCode": ...
    3.     "headers": {"header-key": "header-value", ... },
    5.     "body": "...",
    6.     "isBase64Encoded": true|false
    7. }

    • The statusCode field is an integer used as the HTTP response code. If this key is missing, Envoy returns a 200 OK.

    • The headers are used as the HTTP response headers.

    • The cookies are used as Set-Cookie response headers. Unlike the request headers, cookies are _not_ part of the response headers because the Set-Cookie header cannot contain more than one value per the RFC. Therefore, Each key/value pair in this JSON array will translate to a single Set-Cookie header.

    • The body is base64-decoded if it is marked as base64-encoded and sent as the body of the HTTP response.

    Note

    The target cluster must have its endpoint set to the . Use the same region as the Lambda function.

    AWS IAM credentials must be defined in either environment variables, EC2 metadata or ECS task metadata.

    The filter supports per-filter configuration.

    If you use the per-filter configuration, the target cluster _must_ have the following metadata:

    Below are some examples that show how the filter can be used in different deployment scenarios.

    1. http_filters:
    2.   typed_config:
    3.     "@type": type.googleapis.com/envoy.extensions.filters.http.aws_lambda.v3.Config
    4.     arn: "arn:aws:lambda:us-west-2:987654321:function:hello_envoy"
    5.     payload_passthrough: true

    The corresponding regional endpoint must be specified in the target cluster. So, for example if the Lambda function is in us-west-2:

    The filter can also be configured per virtual-host, route or weighted-cluster. In that case, the target cluster must have specific Lambda metadata.

    1. weighted_clusters:
    2. clusters:
    3. - name: lambda_egress_gateway
    4.   weight: 42
    5.   typed_per_filter_config:
    6.     envoy.filters.http.aws_lambda:
    7.       "@type": type.googleapis.com/envoy.extensions.filters.http.aws_lambda.v3.PerRouteConfig
    8.       invoke_config:
    9.         payload_passthrough: false

    An example with the Lambda metadata applied to a weighted-cluster:

    Statistics

    The AWS Lambda filter outputs statistics in the http.<stat_prefix>.aws_lambda. namespace. The | stat prefix comes from the owning HTTP connection manager.