ILEastic

It is a self contained web application server for the ILE environment on IBM i to run microservices.

ILEastic is a service program that provides a simple, blazing fast programmable HTTP server for your application. You can easily plug your RPG code into a services infrastructure and make simple web applications without the need for any third party webserver products.

Basically it is an HTTP application server you can bind into your own ILE RPG projects, to give you an easy deploy mechanism, that fits into DevOps and microservices environments alike.

The self contained web application server makes it so much easier to develop web applications.

Simply compile and submit. No - You don't need CGI, Apache, nginx or IceBreak - simply compile and submit.

The design paradigm is the same as found in Node.JS - the project was initially called Node.RPG but the name was subject to some discussion, so ILEastic it is. Where Node.JS uses JavaScript, ILEastic aims for any ILE language where RPG is the most popular.

Except for initialization, it only requires two lines of code:

 il_listen ( config : pServletCallback); 
 il_responseWrite ( pResponse);

The il_listen is listening on the TCP/IP port and interface you define in the config structure. For each HTTP request it will call your "servlet" which is a callback procedure that takes a request and a response parameter.

The idea is that you deploy your (open source of course) RPG packages at NPM so the RPG community can benefit from each other's work. The NPM ecosystem is the same for Node.JS and ILEastic.

Example:

**FREE

// -----------------------------------------------------------------------------
// This example runs a simple servlet using ILEastic
// Note: It requires your RPG code to be reentrant and compiled
// for multithreading. Each client request is handled by a seperate thread.
// Start it:
// SBMJOB CMD(CALL PGM(DEMO01)) JOB(ILEASTIC) JOBQ(QSYSNOMAX) ALWMLTTHD(*YES)        
// -----------------------------------------------------------------------------     
ctl-opt copyright('Sitemule.com  (C), 2018');
ctl-opt decEdit('0,') datEdit(*YMD.) main(main);
ctl-opt debug(*yes) bndDir('ILEASTIC');
ctl-opt thread(*CONCURRENT);
/include include/ileastic.rpgle
// -----------------------------------------------------------------------------
// Main
// -----------------------------------------------------------------------------     
dcl-proc main;

    dcl-ds config likeds(IL_CONFIG);

    config.port = 44001;
    config.host = '*ANY';

    il_listen (config : %paddr(myservlet));

end-proc;
// -----------------------------------------------------------------------------
// Servlet call back implementation
// -----------------------------------------------------------------------------     
dcl-proc myservlet;

    dcl-pi *n;
        request  likeds(IL_REQUEST);
        response likeds(IL_RESPONSE);
    end-pi;
  
    il_responseWrite(response:'Hello world');

end-proc;

Your IBM i

In this project there are lots of references to my_ibm_i both in code, development tool and test. This is of course the name of your IBM i. You can do yourself a favor and add the name my_ibm_i to your hosts file and let it point to the IP address of your IBM i - and all the code, development tool and test will work out of the box.

Edit host file

Installation

What you need before you start:

• IBM i 7.2 TR9 (or higher)
• YUM installed from ACS (to install: git and make-gnu (gmake))
• ILE C
• ILE RPG compiler

From a IBM i menu prompt start the SSH daemon: ===> STRTCPSVR *SSHD and start SSH from Win/Mac/Linux.

First install the open source tools:

ssh my_ibm_i
yum install git
yum install make-gnu

Now you are ready to clone the ILEastic git repo:

mkdir /prj
cd /prj 
git -c http.sslVerify=false clone --recurse-submodules https://github.com/sitemule/ILEastic.git
cd ILEastic
gmake  

Now you have library ILEastic on your IBM i - and you are good to go. You can simply copy the service programs to you own project libraries along with the binding directory and header files. (You can skip the *MODULE objects.)

If you'd like to try the examples then you need to build them as well - as simple as:

cd examples 
gmake

Test it:

Log on to your IBM i. From an IBM i menu prompt

CALL QCMD
ADDLIBLE ILEASTIC
SBMJOB CMD(CALL PGM(helloworld)) ALWMLTTHD(*YES) JOB(helloworld) JOBQ(QSYSNOMAX) 
SBMJOB CMD(CALL PGM(staticfile)) ALWMLTTHD(*YES) JOB(staticfile) JOBQ(QSYSNOMAX) 

Look for the complete list in the examples folder - and observe which port they are "listening" at.

Now test it in a browser:

• http://my_ibm_i:44000 Hello world
• http://my_ibm_i:44012 Simple website demo

Please note that the job requires ALWMLTTHD(*YES).

Develop

You compile the project with gmake, and I have also included a setup folder for vsCode so you can compile any changes with Ctrl-Shift-B. You need however to add the name my_ibm_i to your host file since the .vsCode/tast.json file refers to this name. The compile feature also requires that you have SSH started: STRTCPSVR *SSHD

Unit Tests

For executing the unit tests located in the folder unittests you need to previously install either iRPGUnit or RPGUnit.

Moving on

So far we have implemented the basic features like il_listen, il_responseWrite and il_addRoute - look at the prototypes in ILEastic.rpgle header file for the complete list of features. There is still much work to do, however - all the plumbing around git / compile / deploy is working. We at Sitemule.com are striving to move the core of the IceBreak server into the ILEastic project over the next couple of months. So stay tuned.

Note

This project was initially call Node.RPG, however people could not find the node.js code :) so obvously it was a bad name. Thanks for the feedback pointing me into a better direction.

Happy ILEastic coding!