eb-worker-sample

A sample application for AWS Elastic Beanstalk worker tier, implemented in node.js. This application fetches image file from remote server and upload it to Amazon S3.

How it works

aws-sqsd polls Amazon SQS. When message found, it makes HTTP POST request to node.js via nginx.

Architecture

SQS <-(polling)- aws-sqsd -> nginx(port:80) -> node.js(port:8081)

Message structure

header

{
 "host":"localhost",
 "x-real-ip":"127.0.0.1",
 "x-forwarded-for":"127.0.0.1",
 "content-length":"4",
 "content-type":"application/json",
 "user-agent":"aws-sqsd",
 "x-aws-sqsd-msgid":
 "6d4d9535-2325-4099-8711-1aad537e8cce",
 "x-aws-sqsd-receive-count":"7",
 "x-aws-sqsd-first-received-at":
 "2014-10-21T11:01:06Z",
 "x-aws-sqsd-queue":"#<AWS::SQS::Queue:0x007f037cda3348>
}

body

Message itself. If you pass '{"url":"some_url"}', it will come up as string, so you can use it by parsing as JSON to map.

How to use

You need AWS Elastic Beanstalk Command Line Tool.

git clone https://github.com/imaifactory/eb-worker-sample.git
cd eb-worker-sample
eb init # Configuration wizard will come up. You should choose node.js environment.
eb start # Start eb environment.

Then you have to configure environment variables to specify your Amazon S3 bucket.

Also you need to configure instance profile or AWS credentials as environment variables.

Now you can deploy the app.

git aws.push # Deploy code to eb environment.

Then you can pass a message to Amazon SQS. Please note that SQS Queue will be automatically created by AWS Elatic Beanstalk. The message format is here.

{"url":"http://example.com/PATH/TO/IMAGE/sample.jpg"}

Finally, you can find the image file on Amazon S3.