https://github.com/mhjort/ring-apigw-lambda-proxy
Ring middleware for handling AWS API Gateway Lamdbda proxy Requests and responses
https://github.com/mhjort/ring-apigw-lambda-proxy
aws-apigateway aws-lambda ring-middleware
Last synced: about 1 month ago
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Ring middleware for handling AWS API Gateway Lamdbda proxy Requests and responses
- Host: GitHub
- URL: https://github.com/mhjort/ring-apigw-lambda-proxy
- Owner: mhjort
- License: mit
- Created: 2017-01-13T06:22:19.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2018-05-06T18:24:12.000Z (about 7 years ago)
- Last Synced: 2025-03-02T14:50:37.360Z (3 months ago)
- Topics: aws-apigateway, aws-lambda, ring-middleware
- Language: Clojure
- Size: 21.5 KB
- Stars: 8
- Watchers: 2
- Forks: 6
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGES.md
- License: LICENSE
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README
# ring-apigw-lambda-proxy
[](https://travis-ci.org/mhjort/ring-apigw-lambda-proxy)
Ring middleware for handling AWS API Gateway Lamdbda proxy Requests and responses
Note! UTF-8 is used as encoding everywhere. HTTP response contains always message-body, so using HEAD should be avoided.
## Installation
Add the following to your `project.clj` `:dependencies`:
```clojure
[ring-apigw-lambda-proxy "0.4.0"]
```
## Usage
This library can be used to wrap AWS Lambda API Gateway request and response
so that they can be used together with Ring. It takes AWS API Gateway request
as input parameter (parsed from JSON with keywords) and creates Ring compatible
request map. Same way it transforms Ring response map to AWS API Gateway response
map which can be marshaled to JSON back.
Note! This is not a standard Ring Middleware because this has to be always first
middleware in a chain.
AWS Lambda JSON Rest API example.
Add `ring/ring-core`, `ring/ring-json`,`compojure`,`lambdada` and `cheshire` dependencies.
```clojure
(ns example
(:require [uswitch.lambada.core :refer [deflambdafn]]
[cheshire.core :refer [parse-stream generate-stream]]
[clojure.java.io :as io]
[ring.middleware.apigw :refer [wrap-apigw-lambda-proxy]]
[ring.middleware.params :refer [wrap-params]]
[ring.middleware.keyword-params :refer [wrap-keyword-params]]
[ring.middleware.json :refer [wrap-json-params
wrap-json-response]]
[ring.util.response :as r]
[compojure.core :refer :all]))
(defroutes app
(GET "/v1/hello" {params :params}
(let [name (get params :name "World")]
(-> (r/response {:message (format "Hello, %s" name)})))))
(def handler (wrap-apigw-lambda-proxy
(wrap-json-response
(wrap-json-params
(wrap-params
(wrap-keyword-params
app))))))
(deflambdafn example.LambdaFn [is os ctx]
(with-open [writer (io/writer os)]
(let [request (parse-stream (io/reader is :encoding "UTF-8") true)]
(generate-stream (handler request) writer))))
```
It is a common to use AWS Scheduled Events to warmup the Lambda function.
For this case `ring-apigw-lambda-proxy` provides a configuration where
Scheduled Event can be mapped to regular Ring GET route like this:
```clojure
(wrap-apigw-lambda-proxy app {:scheduled-event-route "/warmup"})
(defroutes app
(GET "/warmup" request {:status 200 :body "Scheduled event for warmup"}))
```
If you have not configured `:scheduled-event-route` and Lambda function is
called via Scheduled Event the error will be thrown.
## Design
This is a tiny library with zero dependencies. That is the reason why JSON
parsing of AWS API Gateway request/response is not included.