LPI 701-100 - DevOps Tools Engineer

In Prometheus, the scrape_config section of the configuration file defines how and which nodes (targets) should be scraped (monitored). This section specifies the endpoints Prometheus should scrape, the frequency of scraping, and any relabeling configurations.

scrape_config: This is the correct section where you define the targets to be monitored by Prometheus.

The other options are incorrect:

B. targets: This is part of scrape_config but not a top-level configuration section.

C. rules: This section is used to define alerting and recording rules, not targets.

D. listener: This is not a standard section in Prometheus configuration.

E. nodes: This is not a standard section in Prometheus configuration.

References:

Prometheus Documentation - Configuration

In Kubernetes, a Deployment manages ReplicaSets and ensures that the specified number of replicas for a given Pod is always maintained. If a Pod managed by a ReplicaSet is terminated (e.g., using the command kubectl delete pod ), the ReplicaSet detects the discrepancy in the desired state (number of replicas) and the actual state. As a result, the ReplicaSet will immediately create a new Pod to replace the terminated one and maintain the desired number of replicas.

Deployment Management: A Kubernetes Deployment is responsible for maintaining the desired state of Pods through ReplicaSets.

ReplicaSet Functionality: A ReplicaSet ensures that a specified number of Pod replicas are running at all times.

Pod Termination: When a Pod is terminated, the ReplicaSet notices the reduction in the number of running Pods.

Replacement Pod Creation: To restore the desired state, the ReplicaSet automatically creates a new Pod to replace the terminated one.

References:

Kubernetes Documentation - Deployments

Kubernetes Documentation - ReplicaSet

REST (Representational State Transfer) is an architectural style for designing networked applications. It relies on a stateless, client-server, cacheable communications protocol -- the HTTP protocol. The main HTTP methods used in REST are:

GET: This method is used to retrieve data from a server at the specified resource.

PUT: This method is used to update or create a resource at the specified URL.

DELETE: This method is used to remove a specified resource.

The other options are not standard HTTP methods used in REST:

CREATE: This is not a standard HTTP method. The equivalent standard method for creating resources is POST.

REPLACE: This is not a standard HTTP method. The equivalent standard methods for replacing resources are PUT or PATCH.

References:

RESTful Web Services - HTTP Methods

MDN Web Docs on HTTP Methods

When using cloud-init, a widely used tool for early initialization of cloud instances, the first line of a user-data script must indicate the type of content. For YAML configuration, the correct first line is #cloud-config.

#cloud-config: This line tells cloud-init that the following content is YAML formatted and should be processed as a cloud-config file.

The other options are incorrect:

A. cloud-config: Incorrect syntax.

B. --- cloud-config: Incorrect syntax.

C. #!/usr/bin/cloud-init: This is not the correct first line for a YAML configuration file.

D. [cloud-config]: Incorrect syntax.

References:

Cloud-Init Documentation - Examples

The command docker service create --name myweb --network webnet --mode global nginx creates a Docker Swarm service named myweb using the nginx image. The --mode global option specifies that the service should run exactly once on each node in the Swarm cluster.

Global Mode: When a service is created in global mode, Docker Swarm ensures that exactly one instance of the service runs on each node. This is useful for tasks that should run on all nodes, such as monitoring agents.

The other options are incorrect:

A: It does not run exactly one time in the Swarm; it runs once on each node.

C: This describes the replicated mode, not the global mode.

D: The service runs on all nodes, not just those providing the webnet network.

E: There is no network type called global.

References:

Docker Documentation - Service Create

Docker Documentation - Swarm Services

Ansible provides several modules to manipulate the contents of files. The correct modules for changing the contents of a file are:

lineinfile: This module ensures a particular line is present or absent in a file, or it can replace existing lines that match a pattern.

replace: This module performs a search and replace on a string in a file.

patch: This module applies a patch to a file. It can be used to apply diffs to files, which essentially modifies the contents based on the diff provided.

The other options, insert and modify, are not standard Ansible modules for file content manipulation.

References:

Ansible Documentation - lineinfile module

Ansible Documentation - replace module

Ansible Documentation - patch module

In Ansible, the become keyword is used to control privilege escalation. This allows a user to execute tasks with different privileges, such as running tasks as the root user. When become is set to yes, Ansible will use the configured method (such as sudo, su, or others) to elevate privileges.

become: This directive allows users to control privilege escalation for the tasks they are running. When set to yes, it enables the use of privilege escalation.

priv_user, elevate, super, and sudo are not valid Ansible inventory configuration options for controlling privilege escalation.

References:

Ansible Documentation - Privilege Escalation

In Docker, if you reference an image without specifying a tag, Docker assumes the tag to be latest. The latest tag is used as the default tag for the most recent stable version of the image.

References:

Docker Documentation - Images

Content Delivery Networks (CDNs) are systems of distributed servers that deliver web content and media to users based on their geographic location. CDNs improve the performance and availability of content delivery.

Streaming Media: CDNs can handle and stream large media files, such as videos and music, efficiently to clients.

Multiple Locations: CDNs have servers in multiple locations around the world to serve content closer to users, reducing latency.

High Bandwidth and Low Latency: CDNs are designed to serve a large number of clients with high bandwidth and low latency, enhancing the user experience.

References:

What is a CDN?

How CDNs Work