Run jar file with node js on Microsoft Azure

Question

I make a node js web app for generating report. My idea is to use .jasper file (jasper report) to generate these reports. I've tried a bunch of node js library to do this, but nothing seems to work. And finally I proceed to make a .jar file (java) to solve this. The process is as follows:

1. Node js get request from user
2. Node js run .jar file by using child_process. It run something like "java -jar MyApp.jar arg1 arg2 arg3"
3. .jar file generate a pdf and save it to a folder
4. .jar file return the path of newly generated pdf file
5. Node js get the path and return pdf file to user

It run perfectly in my computer. Then I upload it to Microsoft Azure. It seems like the run .jar file step is failed, because no pdf file is created. Can anyone help me or suggest a better way to do this?

Answer 1

I suspect that your Java PDF generation calls into APIs restricted by the App Service sandbox. Most PDF rendering engines use GDI+, which has most functionality restricted by the Azure App Service sandbox. However, this policy is relaxed on dedicated servers. Scaling up to a dedicated server should resolve this problem (ie not the Shared or Free SKU).

Answer 2

If you deployed the NodeJS webapp into MS Azure WebApps, the step 2 of the process could not spawn a child process for running a jar runnable file because the Java runtime environment not included your current Azure WebApp with NodeJS.

There are three suggested way to do this:

1. Using Azure VM to install NodeJS and Java, and deploy your app on the VM as the same as on the local computer. It's the simple way.

2. I searched an open source report software called jsreport . It can be install on MS Azure VM or Cloud Service. You can refer to the download page Run jar file with node js on Microsoft Azure to install it. And there is the jsreport sdk for NodeJS http://jsreport.net/learn/nodejs . If you want to use jsreport on Azure Cloud Service, you need to know how to build NodeJS App on Azure Cloud Service https://azure.microsoft.com/en-us/documentation/articles/cloud-services-nodejs-develop-deploy-express-app/ .

3. Changing your process. NodeJS get request from user and send it with the specified file name and path to the ServiceBus; The jar runnable file modified as a Azure WebJob read the request from the ServiceBus and generate a pdf with the given file name and save it to the given file path on the Azure Blob Storage; NodeJS directly return pdf file to user from Blob Storage.

For Azure WebJob & Service Bus, you can refer to https://azure.microsoft.com/en-us/documentation/articles/web-sites-create-web-jobs/ and https://azure.microsoft.com/en-us/documentation/articles/service-bus-nodejs-how-to-use-queues/ .