JNCIA-DevOps: Junos Automation Stack and DevOps Concepts
Identify concepts and general features of Junos automation and DevOps.
DevOps culture, practices, and tools
The following questions and content come from the Juniper Genius JNCIA-DevOps Practice Exam. I simply copied them over for my own notes and to source additional material on each question. The questions aren’t enough obviously, you have to know the topics the questions are covering so further studying is required from the additional sourced material.
Which two statements about Continuous Delivery are true? (Choose Two)
a) Continuous Delivery is required for Continuous Deployment
b) Continuous Integration is a natural extension of Continuous Delivery
c) Continuous Delivery includes the automated deployment stage
d) Continuous Delivery means that software is deployed on demand when there is a new software build
Notes: Continuous Delivery means that software is deployed on demand at any time (with actual deployment not necessarily happening in an automated way), and Continuous Deployment includes the stage of automated deployment.
Which two statements about the waterfall model of software development are true? (Choose Two)
a) One phase of development must be completed before the next phase can start.
b) Multiple phases of development can be worked on simultaneously, everything must be finished before production.
c) This method lacks flexibility.
d) This method provides a way to make changes quickly and add new features on demand.
Notes: With the waterfall model, the next phase only starts after finishing the previous one. When requirements change and a need to develop new functionality appears, the waterfall model shows its weakness. It is not flexible enough and requires a lot of time before new functionality can be brought to production.
Which two statements are true regarding DevOps? (Choose Two)
a) DevOps is a methodology that ensures that collaboration does not occur across organizational boundaries.
b) DevOps is a methodology used to develop software or systems.
c) DevOps is a methodology that allows for frequent, quick modifications.
d) DevOps is a methodology that is limited to small codebase development.
Notes: DevOps is a combination of technologies, design concepts, mentalities, and ideals that enable high performing IT teams to move fast while maintaining stability. DevOps creates a tight loop of product release and feedback. With DevOps, changes in functionality happen frequently and are moved to production fast.
According to the “Manifesto of Agile Software Development”, what are two main values of Agile? (Choose Two)
a) Customer collaboration is preferred over contract negotiations.
b) Working software is preferred over comprehensive documentation.
c) Tools are preferred over individuals
d) Following a plan is preferred over responding to change.
Notes: The “Manifesto” formulated the main values of Agile as follows:
Individuals and interactions over processes and tools.
Working software over comprehensive documentation.
Customer collaboration over contract negotiations.
Responding to change over following a plan.
What represents the Infrastructure as Code workflow?
a) Code > Code Review > Version Control > Integrate > Deploy
b) Code > Version Control > Code Review > Deploy > Integrate
c) Code > Version Control > Code Review > Integrate > Deploy
d) Code > Code Review > Integrate > Version Control > Deploy > Integrate
Notes: A typical IaC workflow is as follows: the device code is created and then stored in a version control system; next, the device code goes through an automated code review process; it is then integrated back into the master code branch; and finally is deployed out to the network device.
Which two automation tools require an agent to be loaded on a Junos device? (Choose Two)
Notes: To use Puppet with Junos devices, you need to install the jpuppet module on the Junos device. Similarly, to use Chef on Junos device, the Chef client must first be installed.
What are two advantages of the DevOps approach to network automation? (Choose Two)
a) to lower cost
b) to improve quality
c) to perform manual configuration of tasks
d) to rotate job roles
Notes: Among other advantages, DevOps gives you consistency, security, stability and reliability. All of which contribute to increased speed, decreased cost of management per device (opex), and decreased number of configuration errors.
What is the default port of NETCONF connections over SSH?
Notes: The IANA-assigned port for NETCONF-over-SSH sessions is 830.
Which two API languages for NETCONF libraries are supported by JTAC? (Choose Two)
Notes: JTAC supports both Java and Perl, and provides access to both on Juniper’s website.
Which two processes does Junos automation use? (Choose Two)
Notes: The processes most important to Junos automation are the management process (mgd) and JET service processes (jsd). The mgd process handles the automation requests involving the Junos XML API, YANG, REST API and some SNMP functions. The JET service process (jsd) handles automation requests that use the Juniper Extension Toolkit (JET) API.
Which two statements are true regarding the DevOps methodology? (Choose Two)
a) Feedback should be analyzed at each stage of the process.
b) A goal is to make development, test, and production environments as identical as possible.
c) Communication between people should be minimized during the process as much as possible.
d) Code changes should be few and manually tested.
Notes: You need to gather feedback at all stages of production and delivery. Collect feedback from developers, operations, customers, and anyone else who may have information that can help you improve your flow or quality of product. A benefit of both Continuous Delivery and Continuous Deployment is that they contribute to making your development, test, and production environments as identical as possible.