Chef and Puppet Interview Questions and Answers
1. What are the cook and puppet used for?
Answer: Puppet and cook are the main configuration management systems on a UNIX system, at the side of CFEngine, Ansible. over a configuration management tool, Chef, at the side of Puppet and Ansible, is one in every of the industry’s most notable Infrastructure as Code (IAC) tools. (Chef and Puppet Interview Questions)
2. what’s A Resource?
Answer: A resource represents a chunk of infrastructure and its desired state, like a package that ought to be put in, a service that ought to be running, or a file that ought to be generated.
3. what’s Puppet?
Answer: I’ll advise you to 1st provides a little definition of Puppet. Puppet may be a Configuration Management tool that is employed to change administration tasks.
4. what’s Node definition in Puppet?
Answer: A node definition or node statement may be a block of Puppet code that will solely be enclosed in matching nodes’ catalogs. This feature permits you to assign specific configurations to specific nodes.
5. My Servers are All Unique; will Puppet Still Help?
Answer: All servers are a minimum of somewhat distinctive, however only a few servers are unique; hostnames and scientific discipline addresses (e.g.) can forever take issue, however nearly every server runs a comparatively normal OS. Servers also are typically terribly kind of like alternative servers inside one organization — all Solaris servers might need similar security settings, or all net servers might need roughly equivalent configurations — notwithstanding they’re terribly completely different from servers in alternative organizations. Finally, servers are typically needlessly distinctive, in this, they need been designed and managed manually with no try at retentive acceptable consistency. [E Learning Portal]
Puppet will facilitate each on the aspect of consistency and singularity. Puppet will be accustomed to categorical the consistency that ought to exist, notwithstanding that consistency spans whimsical sets of servers supported by any form of knowledge like OS, knowledge center, or physical location. Puppet also can be accustomed to handling singularity, either by permitting the special provision of what makes a given host distinctive or through specifying exceptions to otherwise normal categories. [E Learning Portal]
6. however Do I Manage Passwords On Red Hat Enterprise UNIX system, Centos, And trilby Core?
Answer: As delineate within the sort reference, you wish the Shadow countersign Library, which is provided by the ruby-shadow package. The ruby-shadow library is on the market natively for fc6 (and higher) and may rest on the corresponding RHEL and CentOS variants.
7. however does one take a look at your manifest files?
Explain however you may 1st run syntax checks with puppet program validate command. If you’re exploiting VIM, you’ll be able to use plugins like Syntastic to verify code (or else) use a full-fledged IDE like Geppetto. Also, use puppet-lint to verify additionally to puppet program.
You can add RSpec/cucumber tests to your application. (BE CAREFUL: RUBY skills are required) and use Cucumber in standalone mode to check your manifests.
8. that scripting language is most vital for a DevOps engineer?
Software development and Operational automation need programming. In terms of scripting
Bash is that the most often used UNIX operating system shell that ought to be your 1st automation alternative. it’s a straightforward syntax and is
designed specifically to execute programs in an exceedingly non-interactive manner. a similar stands for Perl that owes a good deal of its quality to be excellent at manipulating text and storing knowledge in databases.
Next, if you’re exploiting Puppet or cook its price learning Ruby is comparatively straightforward to find out, so several of the automation tools are specifically with it.
Java features a Brobdingnagian impact on that backend, though it’s a restricted unfold across Operations.
9. however information fits in an exceedingly DevOps?
Answer: in an exceedingly excellent DevOps world, the DBA is an associate degree integral part of each Development and Operations group and information changes ought to be as easy as code changes. So, you must be able to version and change your information scripts as your application code. In terms of selections between RDBMS, NoSQL or another reasonably storage solutions an honest information style means that fewer changes to your schema of information and additional economical testing and repair virtualization. Treating direction as an associate degree afterthought and not selecting the proper information throughout the first stages of the computer code development lifecycle will forestall the winning adoption of the verity DevOps movement.
10. Describe the foremost vital gain you made up of automating a method through Puppet?
Answer: “I automatic the configuration and readying of UNIX system and Windows machines exploitation Puppet. additionally, to shorten the time interval from one week to ten minutes, I used the roles and profiles paradigm and documented the aim of every module in README to make sure that others may update the module exploitation stinkpot. The modules I wrote are still getting used, however, they’ve been improved by my teammates and members of the community.”
11. what’s Puppet Kick?
Answer: By default Puppet Agent request to Puppet Master when a periodic time was referred to as “run interval”. Puppet Kick may be a utility that permits you to trigger Puppet Agent from Puppet Master.
12. Why shouldn’t I exploit auto-sign for all my clients?
Answer: It is terribly tempting to alter auto-sign for all nodes because it cuts down on the manual steps needed to bootstrap a brand new node (or so to maneuver it to a brand new puppet master).
Typically this may be finished a *.example.com or perhaps * within the auto-sign.conf file.
This, however, is terribly dangerous because it will alter a node to masquerade as another node and find the configuration meant for that node. the explanation for this can be that the node chooses the certificate common name (‘CN’ – sometimes its fqdn, however, this can be absolutely configurable), and therefore the puppet master then uses this CN to seem up the node definition to serve. The certificate itself is keeping, therefore 2 nodes couldn’t connect with identical CN (e.g. alice.example.com), however, this can be not the matter.
The problem lies within the proven fact that the puppet master doesn’t build a 1-1 mapping between a node and therefore the 1st certificate it saw for it, and thus multiple certificates will map to identical node, for example:
Alice. example.com connects, gets node Alice definition.
bob.example.com connects with CN alice.bob.example.com and additionally matches the node Alice definition.
Without car language, it might be apparent that bob was attempting to urge Alice’s configuration – because the puppet sure thing method lists the total fqdn/CN conferred. With auto-sign turned on, bob mutely retrieves Alice’s configuration.
13. will language a CLA modification UN agency owns Puppet?
Answer: The license modification and therefore the demand for a CLA doesn’t modifier UN agency owns the code. this can be a pure license agreement and NOT a Copyright assignment.
14. What Happens throughout The Bootstrap Process?
Answer: throughout the bootstrap method, the node downloads and installs chef-client registers itself with the cooking server, associate degreed will an initial arrival. throughout this arrival, the node applies any cookbooks that are a part of its run-list.
15. What kinds of testing are needed?
Answer: code groups can typically rummage around for the “fair weather” path to system completion; that’s, they begin from the associate degree assumption that code can sometimes work and solely often fail. I think to apply defensive programming in a very pragmatic means, which frequently means that presumptuous that the code can fail and design for those failures. I attempt to incorporate unit check strategy, use of check harnesses, early load testing; network simulation, A/B, and variable testing, etc.
16. What different tools are you acquainted with that may assist you during this role?
Answer: DevOps is therefore various and inclusive that it seldom ends with committal to writing, testing, and systems. A DevOps project would possibly believe information platforms like SQL or NoSQL, arrangement servers like Redis, or configuration and management issue chase systems like Redmine. net applications are fashionable for contemporary enterprises, creating a background with net servers, like Microsoft net data Services, Apache domestic cat, or different net servers, beneficial. make certain to bring across that you simply are acquainted with Agile application lifecycle management techniques and tools.
17. what’s version management and why ought to VCS be used?
Define version management and name however this technique records any changes created to 1 or a lot of files and saves them in a very centralized repository.
VCS tools can assist you to recall previous versions and perform the following:
Go through the changes revamped an amount of your time and check what works versus what doesn’t.
Revert specific files or specific comes back to associate degree older version.
Examine problems or errors that have occurred thanks to a selected modification.
Using VCS offers developers the pliability to at the same time work on a selected file and every one modification is logically combined later.
18. however, is IaC enforced exploitation AWS?
Answer: begin by talking regarding the antique mechanisms of writing commands onto script files and testing them in a very separate setting before readying and the way this approach is being replaced by IaC. the same as the codes written for different services, with the assistance of AWS, IaC permits developers to jot down, test, and maintain infrastructure entities in a very descriptive manner, exploitation formats like JSON or YAML. this allows easier development and quicker readying of infrastructure changes.
As a DevOps engineer, associate degree in-depth information on processes, tools, and relevant technology are essential. you need to even have a holistic understanding of the product, services, and systems in situ. If your answers matched the answers we’ve provided higher than, you’re in nice form for future DevOps interviews. smart luck! If you’re trying to find answers to specific DevOps interview queries that aren’t addressed here, raise them within the comments below. Our DevOps specialists can assist you to craft the proper answer.
19. however are you able to piece systems with Puppet?
Answer: you’ll be able to piece systems with Puppet either in a very client/server design, exploitation the Puppet agent and Puppet master applications, or in a very complete design, exploitation the Puppet apply application.
20. In Puppet wherever coded is configured?
Answer: the situation of the engineer is designed in puppet. conf with the engineer setting, however, note that Puppet Server doesn’t use that setting; it’s its own JRuby-puppet.master-code-dir setting in puppet server. conf. If you’re employing a non-default engineer, you need to modify each setting.
21. what’s the Module layout in Puppet?
On disk, a module could be a directory tree with a selected, sure structure:
Puppet Real-Time eventualities
22. justify the method of putting in modules from the Puppet Forge?
Answer: to put in a module from the Puppet Forge, use the puppet module install command with the total name of the module you would like.
as an example, to put in puppetlabs-apache:
puppet module install puppet labs-apache
23. What’s Special regarding Puppet’s Model-driven Design?
Answer: historically, managing the configurations of an outsized cluster of computers has meant a series of imperative steps; in its rawest state, SSH and a for a loop. This general approach grew additional subtle over time, however, it maintained the additional profound limitations at its root.
Puppet takes a unique approach, that is to model everything — this state of the node, the specified configuration state, the actions taken throughout configuration social control — as data: every node receives a catalog of resources and relationships, compares it to this system state, and makes changes pro re nata to bring the system into compliance.
The benefits go so much on the far side simply healing the headaches of configuration drift and unknown system state: modeling systems as information let Puppet simulate configuration changes, track the history of a system over its lifecycle, and prove that refactored manifest code still produces an equivalent system state. It additionally drastically lowers the barrier to entry for hacking and lengthening Puppet: rather than analyzing code and reverse-engineering the results of every step, a user will simply analyze information, associate degreed sysadmins are ready to add important price to their Puppet deployments with an afternoon’s price of Perl scripting.
24. What Size Organizations ought to Use Puppet?
Answer: there’s no minimum or most organization size which will take pleasure in Puppet, however, there square measure sizes that square measure additional probably to learn. Organizations with solely a couple of servers square measure unlikely to contemplate maintaining those servers to be a true drawback, whereas people who have additional got to think about rigorously however they eliminate manual management tasks.
25. however, Do I Document My Manifests?
Answer: The puppet language includes a straightforward documentation syntax, that is presently documented on the Puppet Manifest Documentation wiki page. The puppet doc command uses this inline documentation to mechanically generate RDoc or hypertext mark-up language documents for your manifests and modules.
26. What if I haven’t signed a CLA?
If you haven’t signed a CLA, then we tend to can’t nevertheless settle for your code contribution into Puppet or issue. language a CLA is extremely easy: merely log into your GitHub account and head to our CLA page to sign the agreement.
We’ve worked laborious to do to seek out to everybody United Nations agency has contributed code to Puppet, however, if you’ve got queries or considerations a few previous contributions you’ve created to Puppet and you don’t believe you’ve signed a CLA, please sign a CLA or contact America for any data.
27. however, would you create a software package deployable?
Answer: the power to script the installation and reconfiguration of software package systems is important towards controlled and automatic amendment. though there’s associate degree increasing trend for brand spanking new software package to modify this, older systems and merchandise suffer from the belief that changes would be infrequent and minor, then build machine-controlled changes troublesome. As an expert United Nations agency appreciates the necessity to show configuration and settings in an exceeding manner accessible to automation, I will be able to work with ideas like Inversion of management (IoC) and Dependency Injection, scripted installation, check harnesses, separation of considerations, command-line tools, and infrastructure as code.
28. however does one expect you’d be needed to multitask as a DevOps professional?
I believe I’ll be expected to:
Focus attention on bridging communication gaps between Development and Operations groups.
Understand system style from associate degree architect’s perspective, software package development from a developer’s perspective, operations and infrastructure from the angle of a seasoned Systems Administrator.
Execute – to be ready to truly do what must be done.
29. Describe two-factor authentication?
Answer: Two-factor authentication could be a security method during which the user provides 2 suggests that of identification from separate classes of credentials; one is usually a physical token, like a card, and also the different is usually one thing memorized, like a security code.
30. what quantity have you ever interacted with cloud-based software package development?
Answer: Share your information around the use of cloud platforms, provisioning new instances, writing new software package iterations with the cloud provider’s Apis or software package development kits, configuring clusters to scale computing capability, managing work lifecycles then on. this is often the right chance to debate container-based cloud instances as another to traditional VMs. Event-based cloud computing, like AWS Lambda, offers another approach to software package development, a boon for skilled DevOps candidates. In your interview, mention expertise handling massive information, that uses extremely ascendable cloud infrastructures to tackle complicated computing tasks.
31. What was your greatest accomplishment on a recent project?
Answer: certify you demonstrate your good understanding of each development and operation. don’t let your answer lean towards one explicit skillset ignoring the opposite. even though you’ve got worked in an associate degree setting whereby you had to figure additional with one skillset, assure the asker that you simply square measure agile in line with the requirements of your organization.
32. What special coaching or education did it need for you to become a DevOps engineer?
Answer: DevOps is an additional attitude or philosophy instead of a skill-set. the standard technical skills related to DevOps Engineers nowadays are Linux systems administration, scripting, and knowledge with one in all the various continuous integration or configuration management tools like Jenkins and cook. What it all boils all the way down to is that no matter skill-sets you’ve got, whereas necessary, don’t seem to be as necessary as having the power to be told new skills quickly to satisfy the requirements. It’s all regarding pattern recognition and has the power to merge your experiences with current necessities. Proficiency in Windows and Linux systems administration, script development, associate degree understanding of structured programming and object-oriented style, and knowledge making and overwhelming quiet Apis would take one a protracted approach.
33. What data does one would like to bootstrap in Chef?
Answer: simply mention the data you would like to bootstrap:
Your node’s hostname or public scientific discipline address.
A user name and positive identification you’ll go online to your node with.
Alternatively, you’ll use key-based authentication rather than providing a user name and positive identification.
34. Why will we use the chef-Jenkins plugin in chef?
Answer: Chef-Jenkins adds the power to use Jenkins to drive continuous readying and synchronization of environments from a lowlife repository.
35. What square measures the advantages of Devops?
Answer: There square measure several edges of mistreatment devops, justify regarding your devops expertise.
Continuous software package delivery
Less complicated issues to mend
Faster resolution of issues
Faster delivery of options
More stable operative environments
More time offered to feature price (rather than fix/maintain)