README.md

HTTP Lambda

A simple golang-based utility which enables AWS Lambda functions to be invoked from an HTTP endpoint. Use if you want to expose Lambda functions over HTTP without using the AWS API Gateway.

Getting Started

Prerequisites

• Local golang installation; see https://nextmetaphor.io/2016/12/09/getting-started-with-golang-on-macos/ for details on how to install on macOS
• gvt package manager for external vendor dependencies. Install with go get -u github.com/FiloSottile/gvt

Install

Building the Code

First restore the vendor dependencies:

$ gvt restore

Alternatively, manually install the vendor dependencies:

$ gvt fetch --revision v1.12.59 github.com/aws/aws-sdk-go
$ gvt fetch --revision v1.0.0 github.com/sirupsen/logrus
$ gvt fetch --revision v1.6.0 github.com/gorilla/mux
$ gvt fetch --revision v1.3.0 github.com/gorilla/handlers
$ gvt fetch --revision v2.2.6 github.com/alecthomas/kingpin

Then simply build the binary:

$ go build -i

Deployment

Command Line Options

Use the --help flag to examine the various command line options available.

$ http-lambda --help
usage: http-lambda [<flags>]

Simple golang-based utility which enables AWS Lambda functions to be invoked from an HTTP endpoint

Flags:
      --help             Show context-sensitive help (also try --help-long and --help-man).
  -h, --hostname=""      hostname to bind to
  -p, --port="18080"     port to bind to
  -c, --certFile="http-lambda.crt"  
                         TLS certificate file
  -k, --keyFile="http-lambda.key"  
                         TLS key file
  -s, --secure           whether to use secure TLS connection
  -l, --logLevel="warn"  log level: debug, info, warn or error

Running The http-lambda Server

Invoke the built server as follows; logs are output to stderr, access logs to stdout. The server listens binds to address localhost on port 18080.

$ http-lambda 1>>http-lambda-access.log 2>>http-lambda.log

Validation

Testing the http

Simply use cURL to invoke a lambda function as follows.

curl -X POST http://localhost:18080/function/myLambdaFunction -d '{"key1":"key1-value","key2":"key2-value"}' 

In the example above, lambda function myLambdaFunction is being called with an input of the following POST body.

{
  "key1": "key1-value",
  "key2": "key2-value"
}

Licence

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.