RPG & PHP REST Services with Apigility

Chuk Shirley Sabel Steel Service, Inc. Club Seiden

Chuk Shirley

• Developing web applications since 2007

• PHP since 2011

• Winner of the 2015 COMMON Innovation Award for Sabel Steel Service’s mobile web application

@chukShirley

chukShirley@gmail.com

Today’s topics• API concepts

• Apigility installation

• Server configuration

• Creating RESTful web services

• Sanitizing input

• Using the toolkit

• Error handling

• Testing

What is an API?

API Terminology

• Examples:

• IBM i OS commands (CRTLIB, DSPJOBLOG)

• jQuery methods (jQuery.ajax(), jQuery.on())

• RPG built-in functions (%DEC, %XLATE)

“An API is a way for two computer applications to talk to each other over a network using a common language that they both understand.”

Jacobson, Daniel and Greg Brail. Sebastopol, APIs: A Strategy Guide Sebastopol, CA: O’Reilly Media, Inc., 2012

• API = “Application Programming Interface”

API Terminology• API vs Web API

• A Web API is an API accessed over HTTP

• Web service vs Web API

• A web service refers to one or many related API functions

• A web API is a collection of web services

Application Layers

PRESENTATION DOMAIN DATA SOURCE

Web (HTML, CSS, JS) PHP Db2

Mobile (Objective C, Cordova) CL, RPG, COBOL, Java Sessions

Toaster app SQL Cache

Web API

Layer Communication

Presentation layer

HTTP Request

HTTP Response

Domain layer

Data source layer

DB Interactions

Web API

Apigility Installation

Requirements

• Code Editor (Zend Studio, RDi, Notepad, etc.)

• Zend Server 6 or above running PHP 5.4.8 or above

• PHP Toolkit and XMLSERVICE Library

• REST Client (optional)

• Postman, cURL, etc.

Development Methods• Local

• Apigility admin UI runs locally

• Edit your code locally

• Push changes to server

• Remote

• Apigility admin UI runs on server

• Edit your code locally (pull files from server first)

• Push changes to server

Download Skeleton App

• Start PASE shell

• Add PHP executable to PATH environment variable

PHP 5.6 and OpenSSL• PHP 5.6 now verifies peer certificates by default

• Download “good known” CA bundle

• Change php.ini setting

Verify OpenSSL Version• Only recent versions of OpenSSL can properly use this

CA bundle.

• Make sure you’re running at least 0.9.8

Too old!

Run Apigility Installer

• Rename the directory to AcmeAPI

• Return to PASE and change directories to /www

• Run the Apigility installer script

Server configuration

Disable OPCache• Enable opcache blacklist in php.ini

• Create file opcache_blacklist.txt and add two entries

Disable APC Cache• Change PHP setting in datacache.ini

• Set zend_datacache.apc_compatibility to “0”

Configure Directory Permissions

• Make /config and /module directories writable by web server

Add Apache Virtual Host• In /www/zendsvr6/conf/httpd.conf

• Template is on next slide

• You’ll need to supply three values:

• Server IP address (10.x.x.x, 192.x.x.x)

• Port number **Choose one that isn’t in use**

• Path to the project

• Restart Zend Server

Listen *:[port] NameVirtualHost *:[port] <VirtualHost *:[port]> ServerName [server ip]:[port] DocumentRoot "/www/AcmeAPI/public" ! SetEnv APPLICATION_ENV "development" AllowEncodedSlashes On ! RewriteEngine on <Location /> RewriteEngine On RewriteCond %{REQUEST_FILENAME} -s [OR] RewriteCond %{REQUEST_FILENAME} -l [OR] RewriteCond %{REQUEST_FILENAME} -d RewriteRule ^.*$ - [NC,L] ! RewriteCond %{REQUEST_URI}::$1 ^(/.+)(.+)::\2$ RewriteRule ^(.*) - [E=BASE:%1] RewriteRule ^(.*)$ %{ENV:BASE}index.php [NC,L] </Location> </VirtualHost>

Apigility Welcome Page

http://[server ip]:[port]/

Creating RESTful web services

Initializing the DB2 TableCREATE TABLE MY_LIB.CUSTOMERS ( ID BIGINT GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1, NO ORDER, NO CYCLE, NO MINVALUE, NO MAXVALUE, CACHE 20), NAME VARCHAR (50), ADDRESS VARCHAR (75));

Designing the URIs

HTTP REQUEST METHOD EXAMPLE URI TASK

GET /customer lists all rowsPOST /customer Creates new row in dbGET /customer/{customer id} fetch a particular rowPUT /customer/{customer id} Update row in db

DELETE /customer/{customer id} Remove row from db

Using the Admin Interface

Project Structure

Sanitizing Input

Adding Validation

Adding Validation

Add Filtering

Add Filtering

Using the toolkit

ZF2 Services

• The toolkit should be used as a service

• Services are configured in the Service Manager

• PHP array

• Assembled at runtime from many locations

• Global application services located at /config/autoload/application.config.php

Adding DB2 Service

Adding Toolkit Service

Using the Toolkit• Use CustomerResourceFactory to inject toolkit object

into CustomerResource

Using the Toolkit• Edit CustomerResource::__construct() to require a

toolkit object and set the value of a class property

Using the Toolkit (PHP)• Within each method reference the toolkit object with

$this->toolkit.

Using the Toolkit (CL)

Using the Toolkit (RPG)

Using the Toolkit (RPG)

Using the Toolkit (PHP)

Error handling

Error handling• Use HTTP response status codes for errors

• Apigility supports API Problem format

• Uses application/problem+json mediatype

Sending the API Problem• You can produce an API Problem with one of two

methods:

• return new \ZF\ApiProblem\ApiProblemResponse()

• throw new Exception()

Throwing an Exception

Throwing an Exception

Testing Your API

Additional Resources

• This presentation’s GitHub repo: github.com/chukShirley/rpg-php-rest-services-apigility

• Apigility documentation: www.apigility.org/documentation

• HTTP status codes cheat sheet: http://httpstatus.es/

Questions?