AWS Interview Questions for Devops - Updates for New

31. What is Continuous Delivery in AWs Devops? 
Answer: Continuous delivery is a software development practice where code changes are automatically built, tested, and prepared for a release to production.

It expands upon continuous integration by deploying all code changes to a testing environment and/or a production environment after the build stage. When continuous delivery is implemented properly, developers will always have a deployment-ready build artifact that has passed through a standardized test process…

32. Does Puppet Run On Windows? 
Answer: Yes. As of Puppet 2.7.6 basic types and providers do run on Windows, and the test suite is being run on Windows to ensure future compatibility. More information can be found on the Puppet on Windows page, and bug reports and patches are welcome.

33. What Characters Are Permitted In A Class Name? In A Module Name? In Other Identifiers? 
Answer:

• Class names can contain lowercase letters, numbers, and underscores, and should begin with a lowercase letter. “::” 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. 

34. How Do I Manage Passwords On Red Hat Enterprise Linux, Centos, And Fedora Core? 
Answer: As described in the Type reference, you need the Shadow Password Library, which is provided by the ruby-shadow package. The ruby-shadow library is available natively for fc6 (and higher) and should build on the corresponding RHEL and CentOS variants.

35. What type of organizations can use Puppet? 
Answer: There is no strict rule about the type of organizations that can benefit from Puppet. But an organization with only a few servers is less likely to benefit from Puppet. An organization with a huge number of servers can benefit from Puppet as this eliminates the need to manually manage the servers.

36. Can Puppet run on servers that are unique? 
Answer: Puppet can run on servers that are unique. Even though there might be very fewer chances of servers being unique since within an organization there are a lot of similarities that exist like the operating system that they are running on, and so on.

37. What are the characters permitted in a class and module name? 
Answer: The characters that are permitted in a class and module name can be lowercase letters, underscores, numbers. It should be with a lowercase letter, you can use “::” as a namespace separator. The variable names can be including alphanumeric characters and underscore and can be case sensitive.

38. How does merging work? 
Answer: An external node Every node always gets a node object (which may be empty or may contain classes, parameters, and an environment) from the configured node_terminus. (This setting takes effect where the catalog is compiled; on the puppet master server when using an agent/master arrangement, and on the node, itself when using puppet apply. The default node terminus is plain, which returns an empty node object; the exec terminus calls an ENC script to determine what should go in the node object.) Every node may also get a node definition from the site manifest (usually called site.pp).

When compiling a node’s catalog, Puppet will include all the following: Any classes specified in the node object is received from the node terminus Any classes or resources which are in the site manifest but outside any node definitions Any classes or resources in the most specific node definition in the site.pp that matches the current node (if site.pp contains any node definitions) Note 1: If site.pp contains at least one node definition, it must have a node definition that matches the current node; compilation will fail if a match can’t be found. Note 2: If the node name resembles a dot-separated fully qualified domain name, Puppet will make multiple attempts to match a node definition, removing the right-most part of the name each time. Thus, Puppet would first try agent1.example.com, then agent1.example, then agent1. This behavior isn’t mimicked when calling an ENC, which is invoked only once with the agent’s full node name. Note 3: If no matching node definition can be found with the node’s name, Puppet will try one last time with a node name of default; most users include a node default {} statement on their site.pp file. This behavior isn’t mimicked when calling an ENC.

39. Explain what you mean by ordering and relationships? 
Answer: By default, Puppet applies resources in the order they’re declared in their manifest. However, if a group of resources must always be managed in a specific order, you should explicitly declare such relationships with relationship meta parameters, chaining arrows, and the require function. Puppet uses four meta parameters to establish relationships, and you can set each of them as an attribute in any resource. The value of any relationship meta parameter should be a resource reference (or array of references) pointing to one or more target resources. before – Applies a resource before the target resource. require – Applies a resource after the target resource. notify – Applies a resource before the target resource. The target resource refreshes if the notifying resource changes. subscribe – Applies a resource after the target resource. The subscribing resource refreshes if the target resource changes.

If two resources need to happen in order, you can either put a before attribute in the prior one or a required attribute in the subsequent one; either approach creates the same relationship. The same is true of notifying and subscribe.

40. What is meant by saying Nagios is Object-Oriented? 
Answer: Answer to this question is pretty direct. I will answer this by saying, “One of the features of Nagios is object configuration format in that you can create object definitions that inherit properties from other object definitions and hence the name. This simplifies and clarifies relationships between various components.”