Developing iRules for BIG-IP

The Developing iRules for BIG-IP course provides networking professionals with the skills they need to leverage the iRules application programming interface (API) on a BIG-IP system for the purposes of customizing application delivery. The course builds on the foundations of the Administering BIG-IP and Configuring LTM courses, demonstrating how to logically design, script, and deploy iRules that help manage common tasks involved with processing traffic on the BIG-IP system. Extensive course labs consist of writing, applying and evaluating the effect of iRules on local traffic, and includes reading content, videos, hands-on labs, and knowledge assessments.
The topics presented in this course are designed for SecOps and DevOps personnel who want to become more adept at leveraging BIG-IP LTM iRules to customize application delivery for their enterprise. Prospective students should have a basic understanding of BIG-IP local traffic concepts, including virtual servers, pools, and profiles.

Exploring BIG-IP iRules Fundamentals

Customizing Application Delivery with iRules

Triggering an iRule

Leveraging Online Resources for iRules Developers

Creating and Deploying iRules

Configure a Simple iRule

Introducing iRule Constructs

Understanding iRule Events and Event Context

Working with iRule Commands

Logging from an iRule Using SYSLOG-NG

Observe Connection Flow and Context

Working with Variables

Working with Operators and Data Types

Working with Control Structures

Incorporating Best Practices in iRules Development

Work with Local Variables and Implement Conditional Logic in an iRule

Mastering Whitespace and Special Symbols

Testing and Troubleshooting iRules: A Phased Approach

Implementing Intelligent Load Balancing and SNAT

Measuring iRule Runtime Efficiency Using Timing Statistics

Measure IF and SWITCH Efficiency

Modularizing iRules for Administrative Efficiency

Using Procedures to Modularize Code in an iRule

Manage Duplicate Events in an iRule

Optimizing Logging from an iRule

Implementing Other iRule Efficiencies

Using Looping Control Structures (Iteration) in iRules

Measure iRule Efficiency When Logging and Looping

Understanding iRule Number Forms and Notation

Working with Strings

Use an iRule to Parse Payload Data

Combining Strings in an iRule

Using iRule String Parsing Functions

Use String Parsing Commands to Extract Criteria for Load Balancing

Accessing and Manipulating HTTP Headers

Parsing the HTTP URI and HTTP Cookies

Selectively Compressing HTTP Data Using an iRule

Explore Using iRule HTTP Commands

Integrating iRules into Web Application Defense

Preventing Common HTTP Attacks

Secure HTTP Traffic

Customizing Application Delivery Behavior with BIG-IP iRules

Working with iFiles to Share Data Across iRules

Working with iRules Data Groups

Implementing Universal Persistence with an iRule

Gathering Custom Statistics from an iRule

Working with the Stream Profile and an iRule to Modify Payload Contents

Working with Tcl Arrays in iRules

Using iRule Static and Global Variables

Using the Session Table to Share Data Across iRules

Learn how to logically plan and write iRules to help monitor and manage common traffic processing tasks on the BIG-IP system. Explore events, functions, commands, variables, operators, and other elements for mastering iRule development. Gain practical experience through hands-on labs using control structures for conditional branching and looping, mastering spacing, grouping, special symbols, and implementing recommended practices for efficiency. Complete additional skill-building exercises incorporating advanced variables, including arrays, static variables, and session tables.
Reference real-world examples extensively, including securing web applications with iRules by preventing common attacks which can abuse HTTP, securing HTTP headers and cookies, and implementing HTTP strict transport security. Develop skills working with strings, including Tcl parsing commands and other parsing functions. Delve into advanced topics such as using iRules with universal persistence and stream profiles, gathering statistics using STATS and ISTATS, and different methods for accessing, manipulating, and selectively applying compression to HTTP traffic.
This course is intended for system administrators, network administrators and application developers responsible for the customization of traffic flow through a BIG-IP system using iRules.

Chapter 1: Introducing the BIG-IP System

Introducing the BIG-IP System

Initially Setting Up the BIG-IP System

Archiving the BIG-IP Configuration

Leveraging F5 Support Resources and Tools

Chapter 2: Getting Started with iRules

Customizing Application Delivery with iRules

Triggering an iRule

Leveraging the DevCentral Ecosystem

Creating and Deploying iRules

Chapter 3: Exploring iRule Elements

Introducing iRule Constructs

Understanding iRule Events and Event Context

Working with iRule Commands

Logging from an iRule Using SYSLOG-NG (LOG Command)

Working with User-Defined Variables

Working with Operators and Data Types

Working with Conditional Control Structures (IF and SWITCH)

Incorporating Best Practices in iRules

Chapter 4: Developing and Troubleshooting iRules

Mastering Whitespace and Special Symbols

Grouping Strings

Developing and Troubleshooting Tips

Using Fiddler to Test and Troubleshoot iRules

Chapter 5: Optimizing iRule Execution

Understanding the Need for Efficiency

Measure iRule Runtime Efficiency Using Timing Statistics

Modularizing iRules for Administrative Efficiency

Using Procedures to Modularize Code

Optimizing Logging

Using High-Speed Logging Commands in an iRule

Implementing Other Efficiencies

Using Looping Control Structures (WHILE, FOR, FOREACH Commands)

Chapter 6: Securing Web Applications with iRules

Integrating iRules into Web Application Defense

Mitigating HTTP Version Attacks

Mitigating Path Traversal Attacks

Using iRules to Defends Against Cross-Site Request Forgery (CSRF)

Mitigating HTTP Method Vulnerabilities

Securing HTTP Cookies with iRules

Adding HTTP Security Headers

Removing Undesirable HTTP Headers

Chapter 7: Working with Numbers and Strings

Understanding Number Forms and Notation

Working with Strings (STRING and SCAN Commands)

Combining Strings (Adjacent Variables, CONCAT and APPEND Commands)

Using iRule String Parsing Functions (FINDSTR, GETFIELD, and SUBSTR Commands)

Chapter 8: Processing the HTTP Payload

Reviewing HTTP Headers and Commands

Introducing iRule HTTP Header Commands

Accessing and Manipulating HTTP Headers (HTTP::header Commands)

Other HTTP commands (HTTP::host, HTTP::status, HTTP::is_keepalive, HTTP::method, HTTP::version, HTTP::redirect, HTTP::respond, HTTP::uri)

Parsing the HTTP URI (URI::path, URI::basename, URI::query)

Parsing Cookies with HTTP::cookie

Selectively Compressing HTTP Data (COMPRESS Command)

Chapter 9: Working with iFiles and Data Groups

Working with iFiles

Introducing Data Groups

Working with New Format Data Groups (CLASS MATCH, CLASS SEARCH)

Chapter 10: Using iRules with Universal Persistence, Stream, and Statistics Profiles

Implementing Universal Persistence (PERSIST UIE Command)

Working with the Stream Profile (STREAM Command)

Collecting Statistics Using a Statistics Profile (STATS Command)

Collecting Statistics Using iStats (ISTATS Command)

Chapter 11: Incorporating Advanced Variables

Reviewing the Local Variable Namespace

Working with Arrays (ARRAY Command)

Using Static and Global Variables

Using the Session Table (TABLE Command)

Processing Session Table Subtables

Counting “Things” Using the Session Table