I have a POST request coming in with a header that I need to play back with the response (Example: "Validation: 123").
The integration returns synchronously, immediately.
The header is entirely non-functional and so doesn't need to be passed through to my integration. It just needs to be passed back with the response to the inbound request.
I am trying to do this by mapping the headers from the method request through to the method response, or via the integration request/response.
For example, I'd like to set the header mapping for the integration response to method.request.header.Validation (ie, identically to the integration request mapping). However, this is disallowed.
Is this the right approach?
This is a limitation of AWS API Gateway.
Related
I have an API Gateway request where I am passing a custom header that is not being passed into the Lambda which is its target. First and foremost, I checked the verbose logs for the API Gateway Instance and can see the custom header called x-treasury-system being passed in and present in Method request headers:
But it is not present in Endpoint request headers:
Which is why I think its not ending up in the Lambda. I have the following header mappings setup - In the Method Request:
And in the Integration Request:
What am I missing? It seems that all is in order to pass that header, I double checked in lambda logs when printing out the headers that it is for sure not coming in.
I have a simple site running on Lambda, using a single proxy resource in API Gateway to route requests to it.
I'm trying to set up some "vanity URLs": someone arriving on /somepath should be redirected to /?source=somepath.
I'm trying to achieve this in API Gateway rather than passing it through to the Lambda app to manage.
I've set up a resource on /somepath, with a Mock integration type.
The Method Response contains only a 302 type, which contains a Location response header.
The Integration Response contains a corresponding 302 response type
The Header Mappings contain a Location header mapped to context.resourcePath
This works, sort of. A request to /somepath returns a 302 response with a Location header value of /somepath.
But how can I format that Header Mapping value to be (i.e.):
/?source=${context.resourcePath}
Is there a way I can do this all in API Gateway, using only a Mock endpoint instead of passing the request through to an actual integration backend to return a header value?
I'm looking for a service that allows me to proxy/modify incoming requests inside AWS.
Currently I am using cloudfront, but that has limited functions.
I need to be able to see user agent strings and make proxy decisions based on that - like reverse proxying to another domain, or routing all requests to /index.html.
Anyone know of a service that within AWS - or outside of AWS.
It sounds like you are describing Lambda#Edge, which is a CloudFront enhancement that allows you to define Lambda functions that will fire at any of 4 hook points in the CloudFront signal flow, and modify the request or generate a dynamic response.
Viewer Request triggers allow inspection/modification of requests and dynamic generation of small responses before the cache lookup.
Origin Request triggers are similar, but fire after the cache is checked. They allow you to inspect and modify the request, including changing the origin server, path, and/or query string, or to generate a response instead of allowing CloudFront to proceed with the connection to the origin.
If the request goes to the origin, then once it returns, an Origin Response trigger can fire to modify the response headers or replace the response body with a different body you generate. The response after this trigger is finished with it is what gets stored in the cache, if cacheable.
Once a reaponse is cached, further firing of the Origin Request and Origin Response triggers doesn't occur for subsequent requests that can be served from the cache.
Finally, when the response is ready, whether it came from the cache or the origin, a Viewer Response trigger can modify it further, if desired.
Response triggers can also inspect many of the headers from the original request.
Lambda#Edge functions are written in Node.js, and are presented with the request or responses as simple structured objects that you inspect and/or modify.
So I have CORS enabled going through the basic setup given by AWS Gateway. However for this API I need to allow Control Origins for all requests and allow credentials.
Here is what it looks like
The issue as you may have guessed is this setup is not allowed by CORS, you can not have a wildcard for Origin and have credentials as true. Normally the work around for this is to just grab the requesting domain and add it into the Origin Header. Which is more or less what I want to do. But I don't know how to get that information and add it as a mapping value. Where does API Gateway store that information and how do i get it?
UPDATE:
I have to pass through HTTP Header Host to my Lambda Function which I should have mentioned earlier, I have tried implementing the Answer below but I cannot access the header to pass it to the Lambda function using the instructions provided. Any more assistance with this is greatly appreciated.
Okay After hours of research and finding bits of information across the internet I have a solution and hopefully it is useful for other people.
To pass an HTTP Header that is not a default value provided by AWS API Gateway and then access that data via a Lambda Function and return that data in the Response Header follow the steps below
In "Method Request" go to "HTTP Request Headers" and add your desired header to capture. ie. if we want to get the host value of the API url you can enter "Host" here. if you want to get the website host of the caller use "Origin"
In "Integration Request" go to mapping templates and create a new template if an "application/json" does not exist, if it does just update it.
This is the important part, pass the header value you set in step 1. To do that write something similar to the following in the Template Box.
{
"origin" : "$input.params().header.Origin",
"host" : "$input.params().header.Host"
}
You can also pass in any url parameters you have defined in the same JSON.
Access the data from Lambda, The integration request passed the information into the "Event" parameter if using Node as the Lambda Backend code. to retrieve the value of any header just use the following within your handler.
event.origin;
When sending back your response from Lambda to API Gateway, it is best to format the response in JSON. Something similar to this.
{
"origin" : event.origin,
"host" : event.host,
"nonHeaderOutput" : "Hello World"
}
In "Integration Response" go to "Header Mappings", if the header you need is not listed you may add it in "Method Response" and it will then appear here. For this example I used "Access-Control-Allow-Origin" and edited the Mapping Value to be integration.response.body.origin
now go to "Mapping Templates and select the content type you want to use, and then edit the template to access the non header responses by adding this to the Template Box
$input.path("$.nonHeaderOutput")
That is it now the header that was sent to the API can be used in your method Response.
Jurgen from API Gateway here.
Thanks for reporting this issue. There is currently no simple way to set it up via the "Enable CORS" feature in the console. However, we are looking into it to improve the user experience for this use case.
As a potential workaround, you could passthrough the Origin header from the client to your backend and parse / create the value for the Access-Control-Allow-Origin header there. Then you would map the Header in the Integration Response from 'integration.response.header.Access-Control-Allow-Origin' to Access-Control-Allow-Origin and return it to the client.
Hope this helps.
Best,
Jurgen
I am creating an http proxy using AWS Api Gateway. I would like to hard code some of the headers and their values to be forwarded as part of the request. I thought this might be possible in the 'Integration Request' portion of the proxy setup, but I can't seem to figure it out.
I'm trying to pass an Authorization header with an oauth key. I don't want to share this key with clients that have access to this service, since I will only provide a subset of access to users of this specific endpoint.
In the Integration Request, you can configure a static header value to be sent to the integration endpoint by putting the value inside of single quotes, e.g. 'my_static_header_value'.
Is it a problem to put those hardcoded headers in the request body ? It not, you could just use a template (in the integration request screen) :
{
"hardcoded_header": "$input.params('hardcoded_header')"
}
Hope this helps.