Support for multiValueHeaders locally #830
Description
Description:
sam local start-api doesn't detect or pass along any of the multiValueHeaders from the lambda response.
This is most notable (for me) because it defaults to application/json content type even though another header is sent, so for example HTML will be displayed as plain text in the browser.
This is because it only checks the headers key in the lamba response, and not the multiValueHeaders key.
The code related to this issue is the _parse_lambda_output method, found here:
https://github.com/awslabs/aws-sam-cli/blob/develop/samcli/local/apigw/local_apigw_service.py#L182-L214
Here's an example lambda response (using https://github.com/stackery/php-lambda-layer).
{
"body": "<html><body>test</body></html>",
"multiValueHeaders": {
"Connection": ["close"],
"Content-type": ["text/html;charset=UTF-8"],
"Date": ["Wed, 05 Dec 2018 00:51:05 +0000"],
"Host": ["localhost:8000"],
"X-Powered-By": ["PHP/7.1.7"]
},
"statusCode": 200
}This works as expected once deployed, just not locally with sam.
See also:
Steps to reproduce the issue:
- Create
template.yamllike this:
AWSTemplateFormatVersion: 2010-09-09
Description: PHP Lambda test
Transform: AWS::Serverless-2016-10-31
Resources:
phpserver:
Type: AWS::Serverless::Function
Properties:
FunctionName: phpserver
Description: PHP Webserver
CodeUri: src/php
Runtime: provided
Handler: index.php
MemorySize: 256
Timeout: 15
Tracing: Active
Layers:
- 'arn:aws:lambda:us-west-2:887080169480:layer:php71:4'
Events:
api:
Type: Api
Properties:
Path: /{proxy+}
Method: ANY- Create
src/php/index.phpwith any content, e.g.:
<html><body>OK</body></html>- Run
sam local start-apiand go tohttp://127.0.0.1:3000/test(or whatever the address).
Observed result:
None of the headers are sent to the browser. Content is displayed as plain text.
The response headers are:
Content-Type: application/json
Content-Length: 4
Server: Werkzeug/0.14.1 Python/2.7.15rc1
Date: Wed, 05 Dec 2018 00:28:36 GMT
Expected result:
sam local start-api detects the Content-Type header from the multiValueHeaders and the correct content type and other headers are sent to the browser. Content in this example is displayed properly as HTML.
Response headers similar to this, which is what I get from AWS once deployed:
content-type: text/html; charset=UTF-8
content-length: 4
date: Wed, 05 Dec 2018 01:36:09 GMT
x-powered-by: PHP/7.1.7
Additional environment details (Ex: Windows, Mac, Amazon Linux etc)
Linux
Output of sam --version:
SAM CLI, version 0.8.1
Optional Debug logs:
2018-12-04 17:41:24 No Content-Type given. Defaulting to 'application/json'.
2018-12-04 17:41:24 127.0.0.1 - - [04/Dec/2018 17:41:24] "GET /test HTTP/1.1" 200 -