We built this function because we needed a simple print strategy for web maps. The function uses PhantomJS and the rasterize script packaged with the PhantomJS examples. We use the function with the AWS Gateway API in request method passthrough mode.
The function will use PhantomJS to render the url passed in and take a screen grab of the rendered page. You can control the size of the screen grap by passing in an optional screenSize argument. You can also resize the screengrab by passing in a outWidth that will respect the aspect ratio of the passed in or default screenSize. The function will return a base64 encoded string of the image.
| argument | default | description |
|---|---|---|
| url | required | url to print |
| screenSize | 1440px*900px | size of the screen to print |
| outWidth | 0 | resize width + will conform to screenSize aspect ration |
You will need to have installed and configured the AWS CLI in order to execute the deploy script. Change the info in deploy.sh with your function name and region. You should depoy the code from an Amazon AMI since some aspect of the project depends on which architecture the build is ran on. I usually ssh into a small Amazon work instance and run the deploy from there.
$ git clone git@github.com:tesera/lambda-phantomjs-rasterize.git
$ cd lambda-phantomjs-rasterize
$ # update deploy.sh with your info
$ ./deploy.sh
We have also included our AWS API configuration swagger JSON file with AWS API Gateway extentions. You can import the swagger file directly using the AWS API GAteway import tool from the AWS API Gateway console. With binary support enabled for image/png the API will convert the base64 string to its binary equivalent if the incomming requests includes an Accept: image.png header. Otherwise it will default to retuning the base64 encoded string.