lambda_s3

README

GoLangS3Lambda

Simplest utility to upload and download files to S3 through AWS Lambda

How to Build locally

1. make build

How to Test locally

1. cp .env.example .env copy the example .env file to use as a base
2. nano .env update the existing values with your own
3. make test

How to Use

1. go get seantcanavan/...

Sample Code

Documentation

Index

• Variables
• func DownloadFileFromS3(region, bucket, name string) ([]byte, error)
• func GetFileHeadersFromLambdaReq(lambdaReq events.APIGatewayProxyRequest, maxFileSizeBytes int64) ([]*multipart.FileHeader, error)
• type UploadRes
  • func UploadFileHeaderToS3(fileHeader *multipart.FileHeader, region, bucket, name string) (*UploadRes, error)

Variables

var ErrBoundaryValueMissing = errors.New("request contained no boundary value in the Content-Type header")

var ErrContentTypeHeaderMissing = errors.New("request contained no Content-Type header")

var ErrDownloadingS3File = errors.New("unable to download the given file from S3")

var ErrEmptyFileDownloaded = errors.New("the provided S3 file to download is empty")

var ErrNewAWSSession = errors.New("error creating new AWS Session")

var ErrOpeningMultiPartFile = errors.New("unable to open *multipart.FileHeader")

var ErrParameterBucketEmpty = errors.New("required parameter bucket is empty")

var ErrParameterNameEmpty = errors.New("required parameter name is empty")

var ErrParameterRegionEmpty = errors.New("required parameter region is empty")

var ErrParsingMediaType = errors.New("error parsing media type from Content-Type header. Make sure your request is formatted correctly")

var ErrReadingMultiPartFile = errors.New("unable to read *multipart.FileHeader")

var ErrReadingMultiPartForm = errors.New("reading of multipart form failed. verify input size is <= maxFileSizeBytes")

var ErrUploadingMultiPartFileToS3 = errors.New("unable to upload *multipart.FileHeader bytes to S3")

Functions

func DownloadFileFromS3

func DownloadFileFromS3(region, bucket, name string) ([]byte, error)

func GetFileHeadersFromLambdaReq

func GetFileHeadersFromLambdaReq(lambdaReq events.APIGatewayProxyRequest, maxFileSizeBytes int64) ([]*multipart.FileHeader, error)

GetFileHeadersFromLambdaReq accepts a lambda request directly from AWS Lambda after it has been proxied through API Gateway. It returns an array of *multipart.FileHeader values. One for each file uploaded to Lambda.

Types

type UploadRes

type UploadRes struct {
	S3Path string
	S3URL  string
}

func UploadFileHeaderToS3

func UploadFileHeaderToS3(fileHeader *multipart.FileHeader, region, bucket, name string) (*UploadRes, error)

UploadFileHeaderToS3 takes a single *multipart.FileHeader from the Lambda request and uploads it to S3. It the upload is successful it returns the full path to the file in S3 as well as the URL for web access.