Is it possible to access the raw url using AWS API Gateway (and Lambda)?
Alternatively, is it possible to access the original, undecoded query string paramters?
We are integrating against a third party service, that calls our API and encodes the query string params from Windows-1252. (E.g. the finnish letter Ä is encoded as %C4 instead of %C3%84). API Gateway seems to automatically decode the query string parameters and assume UTF-8, which means, that Ä (and Ö and Å) result in \ufffd.
For reference: https://www.w3schools.com/tags/ref_urlencode.asp
Damn, it really doesn't look possible...
I started off writing how you can use Lambda Proxy Integration with event.queryStringParameters, but that parses the data into a key-value object.
Then I went down the road of Mapping Templates in API Gateway, but again there doesn't seem to be any property that shows the whole querystring.
As much as I didn't want it to be true, I can only conclude that it is not possible...
I think your best option is to encode the parameter as base64 on the client, then decode in the Lambda function using Object.keys(event.queryStringParameters)[0].
Related
My aim is to create an AWS-AppSync GraphQL API that implements the Relay Cursor Connections Specification. Specifically I want to add opaque cursors for some Elasticsearch queries. My cursor would be the sort values array for the search_after API. But to make them opaque I would like to stringify and base64 encode them before sending them to the client.
I know that AppSync exposes base64 encode and decode through its $util object. But decode returns a type of byte[] and not String. So my Question boils down to how to convert byte[] to String in Velocity?
Can we use the underlying Java for something like this:
new String(bytes)
Unfortunately I don't know which classes are in the AppSync Velocity Context.
Thanks in advance :)
Have you tried Base64.getEncoder().encodeToString(bytes)?
I have an iOS app that calls a AWS Lambda function. I would like the Lambda function to get some files from a server and send it back to the iOS app, through the Lambda proxy feature.
I am directly invoking the Lambda function from my app using the generated SDK. I couldn't find a documentation explaining how to exchange data other than JSON encoded requests.
How should I go about this?
Lambda's only interface to the outside world is JSON.
To return text data from Lambda, you have to return it as a string, and deserialize the string from the JSON response.
To return binary data from Lambda, the data must be first transformed (encoded) using an encoding that cannot ever produce a series of bytes that is not also a valid sequence of UTF-8 characters, because JSON cannot serialize non-character data (and not every possible combination of bytes corresponds to a valid character or characters). The common strategy for doing this is to use base-64 encoding. Base-64 losslessly converts a series of bytes (octets) into a different series of bytes that are also always valid 7 bit ASCII characters, using an 8:6 conversion ratio (coding 6 bits per byte). You would then need to decode this data back from base-64 to binary.
You can do this decoding of JSON and base-64 on the client, but there are also a couple of other options, if you don't like that idea.
Both API Gateway and CloudFront's Lambda#Edge feature provide a built-in conversion capability to convert the base-64 payload (from the JSON Lambda response) back to binary, if you don't want to do it on the client.
API Gateway supports all Lambda runtimes, and expects this format...
"isBase64Encoded": true,
"body": "the-base-64-encoded-body",
Lambda#Edge supports only Node.js Lambda functions, but is less expensive than API Gateway. It expects a base-64 response to include...
"body": "the-base-64-encoded-body",
"bodyEncoding": "base64",
The viability of either approach depends on your security needs. API Gateway supports authentication via IAM as well as other mechanisms. CloudFront + Lambda#Edge doesn't support IAM auth but can be used with CloudFront signed URLs or Cognito or other custom authorization mechanisms.
If the "files" you mentioned are coming from a server, API Gateway can also proxy these files directly from the server, without a Lambda function handling the content (though depending on your security needs, a Lambda Custom Authorizer might be desirable, to authenticate the request but then simply tell API Gateway to allow the request to be forwarded to the backend).
Or, if the files are objects from S3, then you can access S3 directly, similiar to the way you are accessing Lambda, now.
I've got an API with an integration to S3 to serve static files. My resource is quite simple in that I only require the filename to serve the file, like so:
/api/v1/{file}
However this requires the consumer to know the exact filename, i.e.
/api/v1/purple.json
I want to make this a little more dynamic. Since my files are all JSON, I want the consumer to not have to provide the .json suffix. Is this currently possible with the URL path parameters? I know I can use method.request.path.file to access the purple value, but can I append .json to it myself?
API Gateway does not currently allow for concatenation of values in parameter mapping. This is a feature other customers have requested and is on our backlog.
I'm a newbie rails programmer, and I have even less experience with all the AWS products. I'm trying to use lambda to subscribe to and consume an rss feed from youtube. I am able to send the subscription request just fine with HTTParty from my locally hosted rails app:
query = {'hub.mode':'subscribe', 'hub.verify':'sync', 'hub.topic': 'https://www.youtube.com/feeds/videos.xml?channel_id=CHANNELID', 'hub.callback':'API Endpoint for Lambda'}
subscribe = 'HTTParty.post(https://pubsubhubbub.appspot.com/subscribe, :query=>query)
and it will ping the lambda function with a get request. I know that I need to echo back a hub.challenge string, but I don't know how. The lambda event is empty, I didn't see anything useful in the context. I tried formatting the response in the API gateway but that didn't work either. So right now when I try to subscribe I get back a 'Challenge Mismatch' error.
I know this: https://pubsubhubbub.googlecode.come/git/pubsubhubbub-core-0.3.html#subscribing explains what I'm trying to do better than what I just did, and section 6.2.1 is where the breakdown is. How do I set up either the AWS Lambda function and/or the API Gateway to reflect back the 'hub.challenge' verification token string?
You need to use the parameter mapping functionality of API Gateway to map the parameters from the incoming query string to a parameter passed to your Lambda function. From the documentation link you provided, it looks like you'll at least need to map the hub.challenge query string parameter, but you may also need the other parameters (hub.mode, hub.topic, and hub.verify_token) depending on what validation logic (if any) that you're implementing.
The first step is to declare your query string parameters in the method request page. Once you have declared the parameters open the integration request page (where you specify which Lambda function API Gateway should call) and use the "+" icon to add a new template. In the template you will have to specify a content type (application/json), and then the body you want to send to Lambda. You can read both query string and header parameters using the params() function. In that input mapping field you are creating the event body that is posted to AWS Lambda. For example: { "challenge": "$input.params('hub.challenge')" }
Documentation for mapping query string parameters
I have a Lambda function that is mapped to a HTTP endpoint using the AWS API Gateway. This works fine, I have mapped query string params to the Lambda event, everything works:
https://api.buzzcloud.xyz/?count=999
Which I can call from http://buzzcloud.xyz
I would like to enable caching, but it seems that by default the API Gateway uses the URL for caching, and so changes in my query string parameters are not triggering a different cache result.
The result is that with caching on, my page returns whatever data was first requested and put in the cache.
How do I set a custom cache key or ensure querystring is part of the cache identifier?
Turns out the is a not-so-secret setting that I totally missed that allows for the exact query string params that should be used for the cache to be set.