TCL based iRule is a force-multiplier when it comes to Application Delivery Networking utilizing F5 devices. However, it is essential to understand the interaction of iRule with the normal application.
As an F5 iRule administrator, it is essential to understand the responsibility of maintaining the code. Does this fall within the realm of Application Delivery Engineers or DevOps ? This would depend on the organization and the roles for different people and frankly, there is no clear cut answer to this question.
Having said that, I believe iRule can be used effectively to perform the following functions based on the information available within the header or content of the packet, without affecting DevOps:
- Load Balance to Pools of Servers
- Persistence actions
- Serving Sorry Page or Sorry URL
Load Balancing & Persistence actions will not alter the content of the packet and hence, it should be easily achieved without disrupting the Developers. The 2 functionalities provided do not affect the code but the header or content of the packet is utilized to pick the right server or pool of servers.
- Redirects to specific URL
- Changing contents of header or packet
For redirects and for altering contents of header or packet, it is essential that the Dev team is aware of the traffic flow. This will prevent any conflicting functionality that may disrupt the normal application delivery.