Features of Puppet
Feature	Description
Infrastructure Automation	It defines and continuously enforces the IT configurations no matter where your infrastructure lives.
Automated Provisioning	It provides an automated provisioning across your heterogeneous IT infrastructure.
Task Management	It can make changes or remediate urgent problems alongside the model-driven automation management.
Visualization & Reporting	It gives you an insight into your infrastructure, audit changes, & get rich reporting in a graphical console.
Code Management	It manages the infrastructure as code using version control systems to enable continuous delivery.
Discovery & Insights	It can quickly discover resources that need automated management and drive change.
Orchestration	It lets you orchestrate change with control, visibility, & automated intelligence.

Puppet has a Master-Slave architecture in which the Slave has to first send a Certificate signing request to Master and Master has to sign that Certificate in order to establish a secure connection between Puppet Master and Puppet Slave as shown on the diagram below. Puppet Slave sends a request to Puppet Master and Puppet Master then pushes configuration on Slave.

Puppet is an open-source configuration management tool for deployment, configuration, and management of servers. You can also define Puppet Enterprise as a DevOps software platform tailored for automating infrastructure administration tasks. The different features of Puppet include infrastructure automation, automated provisioning, task management, code management, visualization, and reporting. Puppet also provides features for orchestration as well as discovery & insights.

Puppet is a tool utilized for configuration management on both UNIX based and Microsoft windows working frameworks. Its principal objective is to make the administration of countless machines less complex, progressively solid, and with more automation. Puppet utilizes its own definitive language to depict the arrangement of a framework or system of frameworks. It is likewise generally used to automate system administration tasks.

What are Puppet Manifests?

It is a very important question and just make sure you go in a correct flow according to me you should first define Manifests.

Every node (or Puppet Agent) has got its configuration details in Puppet Master, written in the native Puppet language. These details are written in the language which Puppet can understand and are termed as Manifests. Manifests are composed of Puppet code and their filenames use the. pp extension.
Now give an example, you can write a manifest in Puppet Master that creates a file and installs apache on all Puppet Agents (Slaves) connected to the Puppet Master.

What is Puppet Module and How it is different from Puppet Manifest?

A Puppet Module is a collection of Manifests and data (such as facts, files, and templates), and they have a specific directory structure. Modules are useful for organizing your Puppet code, because they allow you to split your code into multiple Manifests. It is considered best practice to use Modules to organize almost all of your Puppet Manifests.

Puppet programs are called Manifests. Manifests are composed of Puppet code and their file names use the .pp extension.

How Puppet Works?

The Puppet Agent sends the Facts to the Puppet Master. Facts are basically key/value data pair that represents some aspect of Slave state, such as its IP address, up-time, operating system, or whether it’s a virtual machine. I will explain Facts in detail later in the blog.
Puppet Master uses the facts to compile a Catalog that defines how the Slave should be configured. Catalogis a document that describes the desired state for each resource that Puppet Master manages on a Slave. I will explain catalogs and resources in detail later.
Puppet Slave reports back to Master indicating that Configuration is complete, which is visible in the Puppet dashboard.

What is Facter in Puppet?

Facter is basically a library that discovers and reports the per-Agent facts to the Puppet Master such as hardware details, network settings, OS type and version, IP addresses, MAC addresses, SSH keys, and more. These facts are then made available in Puppet Master’s Manifests as variables.

What is Puppet Catalog?

When configuring a node, Puppet Agent uses a document called a catalog, which it downloads from a Puppet Master. The catalog describes the desired state for each resource that should be managed, and may specify dependency information for resources that should be managed in a certain order.

If your interviewer wants to know more about it mention the below points:

Puppet compiles a catalog using three main sources of configuration info:

Agent-provided data
External data
Puppet manifests

What size organizations should use Puppet?

There is no minimum or maximum organization size that can benefit from Puppet, but there are sizes that are more likely to benefit. Organizations with only a handful of servers are unlikely to consider maintaining those servers to be a real problem, Organizations with many servers are more likely to find, difficult to manage those servers manually so using Puppet is more beneficial for those organizations.

How should I upgrade Puppet and Facter?

The best way to install and upgrade Puppet and Facter is via your operating system’s package management system, using either your vendor’s repository or one of Puppet Labs’ public repositories.

If you have installed Puppet from source, make sure you remove old versions entirely (including all application and library files) before upgrading. Configuration data (usually located in/etc/puppet or /var/lib/puppet, although the location can vary) can be left in place between installs.

What is the Command to check requests of Certificates from Puppet Agent (Slave) to Puppet Master?

To check the list of Certificate signing requests from Puppet Agent to Puppet Master execute puppet cert list command in Puppet Master.
If you want to sign a particular Certificate execute: puppet cert sign <Hostname of agent>.
You can also sign all the Certificates at once by executing: puppet cert sign all

What is the use of etckeeper-commit-post and etckeeper-commit-pre on Puppet Agent?

etckeeper-commit-post: In this configuration file you can define command and scripts which executes after pushing configuration on Agent.

etckeeper- commit-pre: In this configuration file you can define command and scripts which executes before pushing configuration on Agent.

What characters are permitted in a class name? In a module name? In other identifiers?

Class names can contain lowercase letters, numbers, and underscores, and should begin with a lowercase letter. “::” (Scope Resolution Operator) can be used as a namespace separator.

The same rules should be used when naming defined resource types, modules, and parameters, although modules and parameters cannot use the namespace separator.

Variable names can include alphanumeric characters and underscores, and are case-sensitive.

Does Puppet run on windows?

Yes. As of Puppet .. basic types and providers do run on Windows, and the test suite is being run on Windows to ensure future compatibility.

Which version of Ruby does Puppet support?

Certain versions of Ruby are tested more thoroughly with Puppet than others, and some versions are not tested at all. Run ruby –version to check the version of Ruby on your system.
Starting with Puppet , Puppet Agent packages do not rely on the OS’s Ruby version, as it bundles its own Ruby environment. You can install puppet-agent alongside any version of Ruby or on systems without Ruby installed.
Puppet Enterprise (PE) also does not rely on the OS’s Ruby version, as it bundles its own Ruby environment. You can install PE alongside any version of Ruby or on systems without Ruby installed.
The Windows installers provided by Puppet Labs don’t rely on the OS’s Ruby version, and can be installed alongside any version of Ruby or on systems without Ruby installed.

Which open source or community tools do you use to make Puppet more powerful?

Changes and requests are ticketed through Jira and we manage requests through an internal process. Then, we use Git and Puppet’s Code Manager app to manage Puppet code in accordance with best practices. Additionally, we run all of our Puppet changes through our continuous integration pipeline in Jenkins using the beaker testing framework.

Tell me about a time when you used collaboration and Puppet to help resolve a conflict within a team?

The development team wanted root access on test machines managed by Puppet in order to make specific configuration changes. We responded by meeting with them weekly to agree on a process for developers to communicate configuration changes and to empower them to make many of the changes they needed. Through our joint efforts, we came up with a way for the developers to change specific configuration values themselves via data abstracted through Hiera. In fact, we even taught one of the developers how to write Puppet code in collaboration with us.

Can I access environment variables with Facter in Puppet?

Not directly. However, Facter reads in custom facts from a special subset of environment variables. Any environment variable with a prefix of FACTER_ will be converted into a fact when Facter runs.

Now explain the interviewer with an example:

$ FACTER_FOO=”bar”

$ export FACTER_FOO</span>

$ facter | grep  ‘foo’</span>

foo => bar

The value of the FACTER_FOO environment variable would now be available in your Puppet manifests as $foo, and would have a value of ‘bar’. Using shell scripting to export an arbitrary subset of environment variables as facts is left as an exercise for the reader.

What are the “etckeeper-commit-post” and “etckeeper-commit-pre” commands?

Candidates can find puppet interview questions related to specific commands and requirements. The “etckeeper-commit-post” is a configuration file for defining scripts and commands. The configuration file runs after the Master pushes configuration on the slave or the agent. The “etckeeper-commit-pre” is also a configuration file for definition of scripts and commands. This command executes before the Master pushes configuration on the Agent.

Which characters are allowed in a class name, module name, and identifiers?

This entry is one of the simplest puppet interview questions and answers for experienced candidates. Class names could have lowercase letters, underscores, and numbers. Class names should always start with a lowercase letter. The Scope Resolution Operator (“::”) is the namespace separator for class names. The characters allowed in the case of Class names are also applicable in the case of defining module names.

The rules are also applicable to the definition of resource types and parameters. However, modules and parameters cannot apply the namespace operator. Variables or identifiers are also subject to certain rules for permitted characters. Variable names are case-sensitive and could include underscores as well as alphanumeric characters.

What versions of Ruby are supported by Puppet?

There are specific versions of Ruby tested specifically for Puppet while some versions are not tested. You can run the command “ruby -version” for checking the version of Ruby on the system. Puppet versions after Puppet do not depend on Ruby version of the OS because it bundles own Ruby environment.

Now, you could install a puppet agent with any version of Ruby or for any systems without installing Ruby. Puppet Enterprise does not depend on the Ruby version of the OS because of the bundling of its own Ruby environment. PE installation with another version of Ruby or in systems without Ruby installation is possible.

What happens if you don’t sign a CLA?

This entry among puppet interview questions is ideal for experienced candidates. Without signing a CLA, code contributions to Puppet or Facter are not accepted. Users should log in their GitHub account for signing the agreement on the CLA page.

What is the process for documentation of manifests?

You can also find this mention among frequently asked puppet interview questions for experienced candidates. The puppet language has a simple documentation syntax. You can find the syntax on the Puppet Manifest Documentation Wiki page. The puppet doc command leverages this syntax for automatic generation of RDoc or HTML documents for modules and manifests.

What is the codedir in Puppet?

Candidates can find this entry among puppet interview questions commonly. The codedir in Puppet is the main directory ideal for puppet data and code. The codedir contains environments that hold manifests and modules. Also, you can find Hiera data and a global modules directory.

Where is the codedir configured in Puppet?

Practical puppet interview questions can fetch better chances of employment. The puppet.conf is ideal for configuration of the location of codedir with the codedir setting. However, Puppet Server uses its JRuby-puppet.master-code-dir Setting with the puppetserver.conf. In the case of non-default codedir, you have to change both settings.

What are permanent and temporary test environments?

Permanent test environment involves a stable group of test nodes. All the changes should be successful for integration with the production code. Test nodes in permanent test environments are smaller versions of the complete production infrastructure. Temporary test environment allows testing of a single change or group of modifications. The testing process involves a review of changes out of version control into the $codedir/environments directory. Temporary test environments have descriptive names or a commit ID from the underlying version.

What is Hiera?

Hiera is a key-value lookup ideal for separation of data from Puppet code. Hiera serves as the in-built key-value configuration data lookup apparatus of Puppet. Hiera is ideal for storing configuration data in key-value pairs. It is also ideal for finding out data needed by a specific module for a given node.

What are Virtual Resources in Puppet?

Virtual Resources in Puppet are instruments for the specification of a particular state of a resource. However, Virtual Resources do not require the implementation of the specific state for the resource. You can declare virtual resources once but can realize them many times.

Is Puppet suitable for managing workstations?

A puppet is an ideal tool for managing almost any machine. Puppet is a major tool for managing various organizations that have various systems.

What are the open-source or community tools for making Puppet more powerful?

Jira is a preferred tool for ticketing changes and requests, thereby providing ease of management through internal processes. Git and Puppet Code Manager app is suitable for managing Puppet code in unison with best practices. Furthermore, the breaker testing framework in the continuous integration pipeline in Jenkins can help in running all Puppet modifications.

What is the difference between a Manifest and a Module?

It is one of the top puppet interview questions that interviewers during the interview. In Puppet, a Manifest is a file that contains Puppet DSL code. It is a .pp file with DSL commands which could contain the necessary, desired, and relevant state configurations. A manifest could be node-specific, and it can be organized into a catalog. Manifests are applicable on a Puppet Agent server or a local server.

Modules can be defined as the structure that is used to create ‘portable cords.’ Mostly, modules encompass manifests, they also generally encompass templates, files, test cases along with metadata. A module that does not contain manifest can also be created.

What do you know about MCollective?

It is one of the best puppet interview questions that candidates are expected to answer to impress the interviewer. MCollective is also known as the Marionette Collective. It refers to a framework that is used for creating parallel job-execution systems or server orchestration. A majority of the users can programmatically execute varying administrative tasks on the collection of servers.

MCollective is the tool that has been designed by Puppet labs so that it can help to run thousands of jobs in parallel while making use of the existing plugins. For interacting parallelly with multiple hosts simultaneously, it uses publish/subscribe middleware.

Why does the Puppet tool have its very own language? Why YAML and XML are considered incompatible?

This is one of the top puppet interview questions that is asked to the candidates during the interview process. The language that is used for manifests is finally the Puppet’s human interface. YAML and XML are the data formats that are developed around the processing capabilities of computer systems, and thus they are not appropriate human interfaces.

Even though there are individuals who can read and write them, YAML and XML restrict the assurance that the specific interface was declarative. There is a possibility that one process will treat a YAML configuration or XML configuration different from another process.

If the servers are all unique, can Puppet be helpful?

This is one of the best puppet interview questions that might seem to be puzzling for an interviewee. The Puppet tool will be helpful even if all the servers are unique. All servers are unique in some way or another, but they are not unique. For instance, even if the IP addresses or the hostname might be different, generally servers run on relatively standard Operating System (OS).

In case a server is unique, Puppet can be useful as it will help in terms of uniqueness as well as consistency. It will help to express the expected consistency, and it can allow special provisions so that the server’s uniqueness can be handled.

Explain Puppet Enterprise.

Puppet Enterprise is scalable across various teams, systems, on-premise, or over cloud servers, by implementing compliance policies and security along with configuration for on-premise and cloud migrating infrastructure with zero downtime.

It also generates reports on the status of code that are built, and information on who and what changes were made on an infrastructure code, trigger analysis checks on regular intervals on infrastructure to assess any impact before any incidence.

Describe Puppet Remediate.

It scans the infrastructure and produces data on vulnerabilities in traceable and auditable formats to prioritize their resolutions. Remediate balances tools that assess vulnerabilities, and prioritize tasks that need immediate resolution, attends such tasks by running pre-built tasks like manage package, services or run the shell script and fix issues immediately.

Explain the working of Puppet Relay.

Puppet Relay monitors your infrastructure and runs automation scripts that not only trigger alerts in case of any incidents using APIs, DevOps tools available by connecting on-premise or cloud connected systems but resets instance using default configuration details present in catalogs from the manifest and finally inform the team of the instance.

What is Bolt?

Bolt automates coordination, management, and setup of computer systems and related services that were processed manually previously, and maintains the entire infrastructure of an organization.

Explain module layout in Puppet.

On disk, a module is a directory tree with a specific, predictable structure:

<MODULE NAME> manifests

Files
Templates
Lib
Facts
Examples
Spec
Functions
Types

What do you understand by module-path in Puppet?

It is one of the most popular puppet interview questions that interviewees are likely to come across during an interview. In Puppet, the puppet master server, as well as the puppet, apply command load a majority of their content from modules that are found in one or more directories.

The list or record of directories where the Puppet tool searches for modules is known as a module path. The environment of the current node sets the module-path. module-path can also be defined as the ordered list of directories where the former directories are given priority over the latest ones.

What is the cache directory in Puppet?

This is one of the most frequently asked puppet interview questions that candidates will come across during the interview process. In Puppet, the cache directory is also known as ‘vardir.’ It refers to the location which contains growing and dynamic data that the Puppet tool creates in the course of the typical and normal operational activities.

Some of the data that is stored in the cache directory can be mined so that interesting analysis can be carried out. It can also be used for integrating other tools with the Puppet tool. Cache directory acts as an indispensable component of the Puppet tool.

What are ‘Divided Infrastructure’ in Puppet?

In case, specific parts of the infrastructure are managed and handled by different teams that do not need to coordinate and align their code; they can be categorized into varying environments. This refers to divided infrastructure in Puppet. The splitting of the different parts of the infrastructure in Puppet is known as “Divided Infrastructur”.

It is one of the key types of “Environments” in Puppet. The other categories of the environment include permanent test environments and temporary test environments. There is no interdependence between the teams that work on the infrastructure, so the splitting of the environment seems to be a feasible option.

What do you understand by “Environments” in Puppet?

It is one of the latest puppet interview questions that are asked to interview candidates. In Puppets, the term “Environments” refers to the isolated groups of Puppet agent nodes. An environment is a branch that converts into a directory in the master.

A Puppet master is responsible for serving every environment with its central manifest as well as a module path. This enables to utilize varying versions of the same modules for different categories of nodes. Thus, it is considered to be extremely useful for making testing changes to the Puppet code before their implementation of the production equipment and machines.

What is store configs?

Storeconfigs is a puppetmaster option that stores the hub’s genuine design to a database. It does this by contrasting the aftereffect of the last aggregation against what is in the database, asset per asset, then parameter per parameter, etc.

How can you use store configs?

The quick utilization of store configs is exported assets. Exported assets are assets that are prefixed by @@. Those assets are checked extraordinarily so they can be gathered on a few different hubs. Some example use cases are:

Share/disseminate open keys (ssh or OpenSSL or different sorts)
Build rundown of hosts running a few administrations (for checking)
Build arrangement documents that require numerous hosts (for example/and so on/resolve.conf can be the link of records sent out by your DNS cache hosts

What do you mean by facter and explain some use cases for the same?

At some point, you have to compose shows on contingent articulation dependent on conditional expression based data which is accessible through Facter. Facter gives data like Kernel adaptation, Distribution discharge, IP Address, CPU information, and so forth. You can characterize your own custom realities. Facter can be utilized autonomously from Puppet to accumulate data about a framework. Regardless of whether it’s parsing the/proc/xen index on Linux or running prtdiag order on Solaris, the tool works superbly abstracting the particular working framework orders used to decide the collection of facts. At the point when utilized related to Puppet, realities assembled through the framework permits the manikin ace to settle on savvy choices during show gathering.

Inside your manikin show, you can reference any key worth sets given by facter by prefixing the hash key with “$”. If the default set of realities are not adequate, there are two different ways to stretch out Facter to give extra truth. One route is to utilize Ruby, the other path is by utilizing condition factors prefixed with FACTER_. S. This permits one to set for every node data and use it in our shows.

What are Manifests?

In Puppet, the files in which client configuration is specified are known as Manifests.

What is MCollective?

MCollective is a powerful orchestration framework. Run actions on thousands of servers simultaneously, using existing plugins or writing your own.

Explain the design patterns you have used in your Puppet code.

Here is a tip to answer this question: Be exceptionally clear on this as this tests your development knowledge rather than sysadmin aptitudes. In any event, you will be tested profoundly on job/profile designs – this is the best and most complex way to deal with looking after code. Notice Anchor patterns and clarify why you are utilizing it. You should just utilize this example before Puppet . or PE ..

Share some best practices for Puppet.

Some accepted procedures are recorded beneath:

Use Modules and Role/Profile design however much as could reasonably be expected.
Keep all code in form control with distributed modules/manifests being sourced from formally tested/released branches.
Utilize environments – Each environment is attached to a particular branch in the version control system.
Utilize Dry runs – use puppet agent – verbose -noop – test.
Manage Puppet module dependencies utilizing librarian Puppet. Version control and manage your Puppetfile
Keep data and code separate. Explicitly keep delicate data inside Hiera YAML documents (which are additionally form controlled).
The trick to doing the above is to utilize JSON records for classified information and YAML for non-confidential data and guarantee physical security to the JSON Folder where nobody aside from the root/puppet client can get to.

Explain rk.

Rk gives a universally useful toolset to conveying Puppet conditions and modules. It executes the Puppetfile design and gives a local usage of Puppet dynamic situations. Rk has two essential jobs: introducing Puppet modules utilizing an independent Puppetfile, and overseeing Git and SVN based unique conditions

What common workflow is used for rk?

A great part of the basic work process relies upon the standard git-flow to create highlight branches and rolling out all improvements in include branches, conveying the earth in test mode, and on the confirmation, converging to a branch before tidying up the highlighted branch. On the off chance that you are not utilizing the standard git-flow, receive likewise.

Can Puppet run on unique servers?

Puppet can run on servers that are interesting. Despite the fact that there may be exceptionally fewer odds of servers being special since inside an association there are a ton of likenesses that exist like the working framework that they are running on, etc.

Explain the architecture of Puppet.

Puppet is Open Source programming. It depends on the Client-server design. It is a Model-Driven framework. The customer is likewise called Agent. What’s more, the server is known as the Master. It has the accompanying building parts:
Configuration Language: Puppet gives a language that is utilized to design Resources. We need to indicate what Action must be applied to which Resource. The Action has three things for every Resource: type, title, and rundown of characteristics of an asset. Puppet code is written in Manifests documents.
Resource Abstraction: We can make Resource Abstraction in Puppet with the goal that we can design assets on various stages. The puppet operator utilizes a Factor for passing the data of a domain to the Puppet server. In Fact, we have data about IP, hostname, OS, and so on of the earth.
Transaction: In Puppet, Agent sends Factor to the Master server. Ace sends back the inventory to the Client. The specialist applies any arrangement changes to the framework. When all progressions are applied, the outcome is sent to the Server.

Can Puppet manage workstations?

Yes, Puppet can manage any machine and is used to manage many organizations that have a mix of laptops and desktops.

What size of organizations utilize Puppet?

There is no base or most extreme organization size that can profit by Puppet, however, there are sizes that are bound to profit. Organizations with just a bunch of servers are probably not going to consider keeping up those servers to be a genuine issue, while those that have more need to consider cautiously how they dispense with manual management tasks.

What characters are permitted in a class name? In a module name or in other identifiers?

Class names can contain lowercase letters, numbers, and underscores, and should begin with a lowercase letter. It can be used as a namespace separator. The same rules should be used when naming defined resource types, modules, and parameters, although modules and parameters cannot use the namespace separator. Variable names can include alphanumeric characters and underscore, and are case-sensitive.

How can I manage passwords on Red Hat Enterprise Linux, CentOS, and Fedora Core?

You need the Shadow Password Library, which is provided by the ruby-shadow package. The ruby-shadow library is available natively for fc (and higher) and should build on the corresponding RHEL and CentOS variants.

What if I am using Puppet .x or earlier?

There will be no change. Puppet ..x remains licensed as GPLv. The license change is not retroactive.

Explain the Puppet catalog.

When configuring a node, the Puppet Agent uses a document called a catalog, which it downloads from a Puppet Master. The catalog describes the desired state for each resource that should be managed and may specify dependency (pivotal training) information for resources that should be managed in a certain order. Puppet compiles a catalog using three main sources of configuration info:

Agent-provided data
External data
Puppet manifests

What commands are used to sign requested certificates?

Below are the commands to sign requested certificates:

puppet –sign hostname-of-agent (.)
puppet ca sign hostname-of-agent (.)

What does it mean if I or my company wants to contribute to Puppet?

As a major aspect of this permit change, Puppet Labs has moved toward each current supporter of the undertaking and requested that they consent to a Contributor License Arrangement or CLA. Marking this CLA for yourself or your organization furnishes both you and Puppet Labs with extra lawful insurances and affirms:

That you own and are qualified for the code you are adding to Puppet
That you are eager to have it utilized in circulations

This gives confirmation that the causes and responsibility for code can’t be questioned in case of any lawful test.

Explain some facts related to Puppet.

Puppet uses a system called Facter to collect system information. This information is related to as “Facts”, and they can automatically be used as variables within your Puppet manifest files. Factor provides data in your manifest files like Kernel version, CPU info, IP Address of the machine, dist release number, and more.

What is a Puppet server?

Puppet Server offers indistinguishable processes and highlights from the exemplary Puppet master program; in any case, Puppet Server runs on the JVM (Java Virtual Machine), doing as such by running the Puppet master codebase inside JRuby interpreters. A few pieces of the exemplary Puppet ace program are reimplemented in Closure in Puppet server.

Explain the potential that could be created by automating a process through Puppet.

In robotizing the setup and sending of different machines in your organization using Puppet, you could abbreviate the procedure from being weeks long to under minutes. In the wake of building up an automation infrastructure configuration and deployment, the procedure you made can be broken into modules and depicted completely in a README, which is then looked into form control like git or svn. This permits future Dev Ops groups to refresh the Puppet modules, change the framework arrangements, and access history or even move back to previous versions of the configured infrastructure.

Explain Puppet Resource.

Puppet assets are the littlest unit of a framework setup. An asset gives a depiction to some part of the framework, for instance, a bundle that must be introduced for help with which the machine must convey. Puppet Catalogs contain arrangements of assets, which together in a Catalog depict the objective condition of the framework and deal with the entirety of the assets introduced on the framework.

Explain Resource type.

A Resource type portrays the sort of configurations managed by a given asset. Puppet comes out of the box with a few resource types, for instance, CRON jobs, service connections, files, and more. Resource types can likewise be extended.

Explain Puppet parser and what’s it uses?

Puppet parser glances through your manifest files to ensure the code inside them contains the right syntax. Puppet parser is particularly valuable as a component of a persistent mix pipeline, since it very well may be utilized as an automated check that forestalls invalid Puppet code from making it into your production environment and damaging infrastructure configurations.

What is divided infrastructure in Puppet?

If parts of your infrastructure are managed by different teams that don’t need to coordinate their code, you can split them into environments.

Explain modules in Puppet.

Modules are self-contained bundles of code and data. These reusable, shareable units of Puppet code are a basic building block for Puppet. Nearly all Puppet manifests belong in modules. The sole exception is the main site.pp manifest, which contains site-wide and node-specific code.

What is Hiera and what is its use in Puppet?

Hiera is a key/value lookup used for separating data from Puppet code. Hiera is Puppet’s built-in key-value configuration data lookup system. Puppet’s strength is in reusable code. Code that serves many needs must be configurable: put site-specific information in external configuration data files, rather than in the code itself. Puppet uses Hiera to do two things:

Store the configuration data in key-value pairsLook up what data a particular module needs for a given node during catalog compilation. This is done via:
Automatic Parameter Lookup for classes included in the catalog
Explicit lookup call

What is PSON?

If you perceive JSON, you would perceive PSON for its similarities. Puppet utilizes PSON so as to serialize information that would then be able to be sent over a system or put away on the nearby document framework. JSON necessitates that the type of the serialized information is UTF-, Unicode encoded, PSON is a progressively nonexclusive -piece ASCII. As a result of its one of a kind encoding, PSON can speak to any succession of bytes as a string. While indicating the PSON MIME type, the best possible sort is “text/pson”.

Explain Puppet Enterprise.

Puppet enterprise is configuration tool or said as an automated code where infrastructure information such as software and their settings are already defined for system and server so that these can be installed, the environment can be set up when new infrastructure is installed and periodic verification is done to ensure that these systems and servers remain in the desired state.

Describe Puppet architecture.

Puppet follows declarative programming approach where code specifies what to do, but does not inform steps on how to do it.

Based on Pull based deployment, agent nodes check on a regular interval of minutes with a master node for anything change at the agent. In case of change requirement, the agent pulls specific code from the master and performs required actions at agent node.

Agent sends Facts, i.e. its state in key/value data pair, to the master. State includes the system’s operating system, up-time i.e. time system is operational, IP address i.e. physical or virtual machine.
Using facts information, master compiles a Catalog that describes how the agent should be configured. Catalog, a document explains the desired state for the agent’s resources, master manages on the agent.
Agent responds to the master with information about completion of configuration, which can be viewed in the Puppet dashboard.

Explain Working of Puppet.

It is explained as follows:
Entities required for running include Puppet Master and Puppet Agent.

Agent or nodes are daemons running on client servers. These servers need some configurations or being managed using Puppet. This agent verifies configurations at regular intervals with the master for any change. Master consists of all configurations stored for different hosts and runs as a daemon on the master server. Agent and master are connected via Secure Sockets Layer (SSL).

Node connects master, master analyzes what configuration and how it can be applied to the node. After analysis, master collects resources and configurations, compiles and makes a catalog, and sends it to the agent of the node. After applying the configuration, the agent submits the report of configuration that was applied to the master server.

Describe the Puppet Module.

Modules are basic building blocks of the puppet in a directory structure that contains classes, tasks, functions, resource providers and their types, and plug-ins like facts or custom types. It is mandatory to have modules installed in the puppet module path. These modules are used to manage tasks such as installation or configuration of software on to system or server.

What is Catalog in Puppet?

Catalog is a document with state details of each resource master that manages on the node. Master compiles a catalog and sends back to the agent. It has data provided by agent at the node, external data, and details related to puppet manifests.

What are classes?

Classes are named squares of Puppet code that are put away in modules for some time in the future and are not applied until they are invoked by name. They can be added to a node’s list by either announcing them in your shows or allocating them from an ENC. Classes for the most part arrange huge or medium-sized lumps of usefulness, for example, the entirety of the bundles, config records, and administrations expected to run an application.

How can you test manifest files?

Clarify how you will initially run linguistic structure checks with manikin parser approval order. In the event that you are utilizing VIM, you can utilize modules like Syntastic to confirm code (or else) utilize a full-fledged IDE like Geppetto. Additionally use puppet build-up to confirm notwithstanding puppet parser. You can add RSpec/cucumber tests to your application. (Be Careful: RUBY aptitudes are required) and use Cucumber in independent mode to test your manifests.

The Marionette Collective called Mcollective.why?

The Marionette Collective, otherwise called MCollective, is a structure for building server coordination or equal occupation execution frameworks. Most clients automatically execute authoritative assignments on groups of servers. MCollective has some special qualities for working with huge quantities of servers:

Rather than depending on a static rundown of hosts to order, it utilizes metadata-based revelation and sifting. It can utilize a rich information source like PuppetDB or can perform constant disclosure over the system.
Rather than legitimately associating with each host (which can be asset serious and moderate), it utilizes distribute/buy-in middleware to impart in corresponding with numerous hosts on the double.

What data source types are supported in HIERA?

JSON and YAML

What is the LDAP node classifier?

LDAP can be used to store information about nodes and servers. The LDAP Node Classifier is used to query LDAP for node information instead of an ENC.

Explain the use of etckeeper-commit-post and etckeeper-commit-pre-on Puppet Agent.

etckeeper-commit-post: In this configuration file, you can define command and scripts which executes after pushing configuration on Agent Etckeeper-commit-pre: In this configuration file you can define command and scripts which executes before pushing configuration on Agent

Explain Puppet Kick.

By default, Puppet Agent requests a Puppet Master after a periodic time which is known as “run interval”. Puppet Kick is a utility that allows you to trigger the Puppet Agent from Puppet Master.

Differentiate between class definition and class declaration.

Defining a class makes it accessible for later use. It doesn’t yet add any assets to the index; to do that, you should declare it or assign it from an ENC.

Explain ordering and relationship.

As a matter of course, Puppet applies assets in the request they’re proclaimed in their show. Be that as it may, if a gathering of assets should consistently be overseen in a particular request, you should unequivocally declare such relationships with relationship meta parameters, chaining arrows, and the required function. Puppet utilizes four meta parameters to set up connections, and you can set every one of them as a trait in any asset. The estimation of any relationship meta parameter should be an asset reference (or array of references) highlighting at least one objective asset.

before – Applies an asset before the objective asset
requires – Applies an asset after the objective asset
notifies – Applies an asset before the objective asset. The objective asset revives if the advising asset changes.
subscribe – Applies an asset after the objective asset. The subscribing resource refreshes if the objective asset changes.

If the two assets need to occur altogether, you can either place a preceding characteristic in the earlier one or a required property in the resulting one; either approach makes a similar relationship. The equivalent is valid for notify and subscribe.

Define Classes in Puppet.

Classes are blocks of code, invoked by their names, present in modules. Classes are used for the functionality of all packages, services, and configuration files needed to run an application. These can be added into the node’s catalog in two possible ways, i.e. declaring these classes in manifests or by assigning from external node classifier.

Classes can be declared in manifest in the following two ways:
Using include class_name OR using class { ‘classname’ : }
Puppet Class structure is explained in figure below:

What is Manifest in Puppet?

All Puppet programs written in Ruby programming language and saved with an extension of .pp, and are built with an intension of creating and managing any host machine in target are called a Manifest.

It contains Files (puppet selects and moves these files to a target location), Templates (used to create configuration files on the node), Nodes (client node related definitions are described at nodes), Resources, and Classes.

Describe in detail about Facter in Puppet.

Facter is a system-profiling cross-platform library that discovers and reports per-node system information known as facts present as variable with values in the key-value format in manifests.

Facters and Facts are available across Puppet code as global variables, they can be used in code without any reference at any point, any place in the code. Facter is a library that identifies the details of the facts that may contain the operating system being used, SSH keys, IP address, verification for the virtual machine or not, MAC addresses, etc.

Various fact types used are explained below:

Core Facts:These are information on resources such as cloud, disks, memory, OS, path, processors, and partitions. We can use the following command to view the complete list of facts and their corresponding values in key-value format.
- $ run puppet facts
Custom Facts:Using export FACTER {fact’s_name} we can add Custom Facts to the node. These facts are customized in order to attend specific requirements by DevOps.
External Facts:To apply facts at the provisioning stage, we can use external facts, apply metadata to virtual machines at AWS, OpenStack cloud providers.

What do you mean by Puppet Kick?

Puppet Kick deprecated in the current version is a utility that triggers agent from the master. As per Ubuntu manuals, ‘puppet kick’ is a script to be run as root to access Secure Sockets Layer (SSL) certificates, connect set of machines that run the agent, and trigger them to run their configurations.

In addition, this command also looks up in Lightweight Directory Access Protocol (LDAP), for hosts matching that configuration, connects with each of them and triggers to run their configuration. In order to kick work, the agent should identify and sense for incoming connections and should have access to permission to run endpoints.

Describe functionality of MCollective in Puppet.

MCollective or Marionette Collective is a framework for creating automated coordination, management, and arrangement of complex infrastructure i.e. Systems and Servers known as Orchestration. Administrative tasks on clusters of servers can be automatically executed using MCollective.

Their components are Servers, Clients, and Middleware. Using MCollective commands we can query the value of facts, start and stop services, start configuration tool itself, as well as query and update software.

What is special about Puppet’s model-driven design?

Previously system administrators were following series of steps to configure and manage infrastructure, which comprises multiple groups of systems and servers. In a model-driven design approach, Puppet, which is an automated code written in Ruby, contains all the configuration details that are compiled into a catalog.

This catalog is sent to every node and shares resources, values, and their relations, the required modification of configuration is made for failed systems to reinstate them back to normal running state.

Give a few use cases for Puppet.

Puppet is used to manage and standardize infrastructure deployment.
Requirement: Startup Company has moved its infrastructure to Cloud service providers such as Amazon web server or Google Cloud services. End User is responsible for the creation, standardization, and maintenance of systems and servers on different platforms, applications, and services and wants to install and use Puppet to ease their task.
Scenario : Administrators utilize tools for standardizing their servers and systems, like the creation of a manifest file which has steps written in configuration code to build their new server.
For example,

Installation of the operating system, say Linux.
Verifying Linux disc space using software File light, or DUC.
Installing Java.
Installing Tomcat.
Installing SQL server as RDBMS.
Installing patch for an application to be built and tested for software development trainee.

Scenario : Creation of file, listing all the above steps in manifest, which can be run using puppet command to perform the steps automatically mentioned in manifest file. This way standardization of steps is followed while deploying new system using manifest and command.
Scenario : Manifest created will be utilized to build Cloud server through the API so that all the manual tasks can be automatically done.

Explain the “etckeeper-commit-post” and “etckeeper-commit-pre” commands.

Following is the difference between both the commands

etckeeper-commit-post is a command written in the configuration file, which can be executed after pushing configuration on the agent.
etckeeper-commit-pre is a command written in the configuration file, which can be executed before pushing configuration on the agent.

List characters that are allowed in a class name, module name, and identifiers?

Following are acceptable characters while declaring the Class name and Module name:

Must begin with a lowercase letter.
Can include lowercase letters, digits, and underscores.
Scope Resolution Operator i.e. “::” are namespace separator in class name definition.

With Variable name, characters accepted are as mentioned below:

Can begin with uppercase and lowercase letters.
May contain numerals and underscores (‘_’).
If the first character is an underscore, then the variable can only be accessible from its own local scope.
Variables are case sensitive.

What to expect if you don’t sign a Contributor License Agreement?

It is a mandatory condition to sign a Contributor License Agreement (CLA) for code contributors to Puppet or Facter, without which their code cannot be accepted. To find and download Puppet or Facter code written in Ruby, the user should log in to their GitHub account and sign an agreement.

Explain the importance and location of codedir in Puppet?

codedir is used by Master and apply command, but not by the agent. It is the main directory for data and code that uses an environment containing manifests and modules, global module directory, and Hiera data and configuration.

This codedir is located at following local directories

In case of Windows: C:\ProgramData\PuppetLabs\puppet\etc
Whereas for Linux: /etc/dir/PuppetLabs/code

Describe Hiera.

Hiera is a lookup system for configuration data in key-value format. It helps in retrieving data from Puppet code. This code utilizes this system for explicit parameter lookup calls for classes from a catalog. This system uses Puppet’s facts to identify data sources. Its ^th version supports data files in JSON, YAML, and EYAML formats.

It searches configuration data in three independent layers of configuration starting from global then environment and finally module layer of configuration.

Describe Virtual Resources in Puppet.

During the Puppet setup, duplicated resource declaration error occurs in case the same resource is used more than once. This tool resolves this issue by introducing a virtual resource. Declaring virtual resource makes its resource available to collectors and realizes function. As well manages state when the resource is realized.

You can find unrealized virtual resources marked inactive included in the catalog. Virtual resources are applied for management of resources whose multiple conditions across classes are met and for overlapped resource sets by multiple classes.

Describe module-path.

Master service and with puppet apply command where Puppet manifests are applied locally, load their content from modules (installed in the puppet modulepath) from one or more of the directories. It is the ordered list of directories searched for modules by Puppet. These directories from modulepath list are separated by a separator character.

In Linux, it is colon (:) and in Windows, it is semi-colon (;).

Give details about base modulepath.

Global module directories list is the base modulepath for applying with all the environments, configured with base modulepath setting, with default value as below:

In case of Linux: $codedir/modules:/opt/puppetlabs/puppet/modules
In case of Windows: $codedir\modules

Describe about Cache directory in Puppet.

Puppet during normal operations, stores generated data in a cache directory called vardir. This data can be mined for analysis. In case of agent and apply command, Cache directory can be found at one of the following locations:
In case of Windows, it is C:\programed\PuppetLabs\puppet\cache
Whereas in Linux it is /opt/puppetlabs/puppet/cache, alternatively, using –vardir option at the command line, will specify puppet cache directory location. We can change the location of vardir files and directories, by changing puppet.conf settings.

Explain about “Environments” in Puppet.

Environment is a logical distribution that separates modules and manifests into separate sections or folders for nodes in order to get bit of code depending on which environment node belongs to, it is statically set in puppet.conf. It is a feature to divide infrastructure configuration into environments Admin can use a single master to serve multiple isolated configurations.

Describe Resources in Puppet.

Puppet Resources uses build, design, and manage system or server infrastructure. This tool has multiple types of resources to build and define new resources to define system architecture. Puppet code block in the manifest file (resource declaration) is created using Declarative Modeling Language (DML).

It contains Resource Type, Resource Parameter, Attributes, and Values.

Explain types of resources in Puppet.

Puppet managed system components are analyzed with the help of resource types. Few common resource types are group, package, user, file, and service.

There are two types of resources, built-in types and custom types. Some of the built-in resource types are group, package, user, file, and service. You can find custom types distributed in puppet modules referred from forge.puppet.com.

Explain Node Definition in Puppet.

Node definition or statement is a puppet code block that matches with node’s catalog. It allows the assignment of a specific configuration to the affected node.

Their syntax looks similar to that of class definitions with node keyword, node definition name, opening curly brace, a mixture of class and resource declarations, collectors, variables, conditional statements, functions, and chaining relationships, finally a closing curly brace.

Describe functions in Puppet.

Puppet Functions are plug-ins that are used during catalog compilation. Function call by manifest makes function run and return value and modifies the catalog as a side effect.

One can create their own functions that accept arguments through parameters to transform data and construct values. These are plug-ins or expressions called in order to resolve to value and can either be a built-in or customized.

Give examples to configure systems using Puppet

Some examples to the system configured with puppet are listed below:

Manage NTP service: Network Time Protocol (NTP) is the most essential services that can be managed and configured using puppet, to synchronize time all across nodes.
Manage Sudo privileges: Sudo command on your agents will identify system users with elevated access privileges.
Manage a DNS name server file: Name server that maps IP addresses understood by computers with human-readable URLs can be managed using this configuration tool.
Manage firewall rules: Various rules and policy like application ports (TCP/UDP), network ports, IP address, and access-deny statements can be designed with firewall, with tool’s firewall policies can be managed.

Describe main or site manifest in puppet.

Agent sends state of resources called facts to master, based on the information received. Master will compile catalog in the form of a single manifest file, known as main or site manifest. The master utilizes the main manifest file, either a single or directory of .pp files, configured by the current node’s environment, which with help of manifest setting in environment.conf, determines the main manifest.

What do you mean by puppet apply?

Puppet apply is a standalone execution command for apply to individual manifest. This code when applied to modulepath via command line or config file, acts like catalog. ‘puppet apply’ is a command-line code for applying a configuration.

List companies that use Puppet.

Few multinational enterprise organizations that use Puppet in their infrastructure management and configuration are:

KPN – Dutch landline and mobile telecommunications company, Netherlands
CERN – European Organization for Nuclear Research
Aegon UK – financial services provider
NYSE – New York Stock Exchange
ICE – Intercontinental Exchange
ANZ Bank
Cisco
Splunk
Google

Explain what pre-installation preparations you will require before installing Puppet Open Source.

There are some preparations and requirements before installing Puppet Open Source

Selection of server as the master.
Validate servers and network are ready and prepared for installation with the following instructions:
- Selection of deployment type for the selected server. We can use Docker compose based stack–puppet ware or in case you already have Docker, then clone the
- run docker-compose up command
Installing agents
Once Puppet Server is configured, we need to install the agent package on node machine on which configuration management tool is needed.
- Based on your operating system, you have Linux, OS X, and Microsoft Windows to select.
You can use NTP and sudoers to automate Puppet code for designing configuration.

So, this brings us to the end of the Puppet Interview Questions blog.
This Tecklearn ‘Top Puppet Interview Questions and Answers’ helps you with commonly asked questions if you are looking out for a job in Puppet or DevOps Domain. If you wish to learn Puppet and build a career in DevOps domain, then check out our interactive Configuration Management using Puppet Training, that comes with 24*7 support to guide you throughout your learning period.

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Continuous Deployment: Configuration Management using Puppet Training

About the Course

Tecklearn has specially designed this Continuous Deployment: Configuration Management using Puppet Training Course to advance your skills for a successful career in this domain. The course will cover different components of Git and GitHub and how they are used in software development operations. The course consists of Configuration Management using Puppet, Puppet Components, important concepts like Puppet Lifecycle, Puppet Language and Puppet Installation. You will get an in-depth knowledge of these concepts and will be able to work on related demos. Upon completion of this online training, you will hold a solid understanding and hands-on experience with Puppet.

Why Should you take Configuration Management using Puppet Training?

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According to Grand View Research, the DevOps market size is estimated to be worth $12.85 billion by 2025. DevOps professionals are highly paid and in-demand throughout industries including retail, eCommerce, finance, and technology.

What you will Learn in this Course?

Introduction to DevOps

What is Software Development
Software Development Life Cycle
Why DevOps?
What is DevOps?
DevOps Lifecycle
DevOps Tools
Benefits of DevOps
How DevOps is related to Agile Delivery
DevOps Implementation

Continuous Deployment: Configuration Management using Puppet

Need of Configuration Management
What is Puppet
Puppet Architecture
Puppet Components
Puppet Lifecycle
Setting up Master Slave using Puppet
Puppet Manifests
Puppet Modules
Applying configuration using Puppet
Puppet File Server
Hands On

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