CJE Distributed Builds & Agent Management 2

Question 1

What is the purpose of the 'agent' directive in a Jenkins Declarative Pipeline?

Accepted Answer

To specify where the entire pipeline or a specific stage should execute

Answer

The 'agent' directive specifies the executor environment — such as a node label, Docker container, or Kubernetes pod — where the pipeline or an individual stage will run.

Question 2

What does 'agent none' at the top level of a Declarative Pipeline mean?

Accepted Answer

No global agent is allocated; each stage must define its own agent directive

Answer

'agent none' at the top level means Jenkins will not allocate a global workspace; instead, each stage is responsible for declaring its own 'agent' directive specifying where it should run.

Question 3

What is the Jenkins best practice regarding the number of executors on the controller node?

Accepted Answer

Set it to 0 so the controller does not run builds and reserves resources for system management

Answer

Best practice is to set the controller's executor count to 0, preventing it from running builds so its resources remain dedicated to managing jobs, agents, and the system.

Question 4

In a Declarative Pipeline using a Docker agent, what does the 'args' parameter in 'docker { image "..." args "..." }' specify?

Accepted Answer

Additional flags passed directly to the 'docker run' command when starting the container

Answer

The 'args' parameter passes additional command-line flags to 'docker run', allowing customization such as adding volume mounts (-v), environment variables (-e), or privileged mode (--privileged).

Question 5

What is a 'flyweight executor' in Jenkins?

Accepted Answer

A lightweight executor on the controller used for administrative tasks like SCM polling and pipeline orchestration steps

Answer

Flyweight executors run on the Jenkins controller and handle non-build operations such as SCM polling, pipeline step coordination, and trigger evaluation without consuming regular build executor slots.

CJE - Certified Jenkins Engineer Practice Test

CJE - Certified Jenkins Engineer Practice Test

CJE Distributed Builds & Agent Management 2