¿QUE ES KUBERNETES? - Introducción al orquestador más usado

Pelado Nerd

22 Sept 202007:57

Summary

TLDRThis video offers an introductory explanation of Kubernetes, a container orchestration tool created by Google and now open source. It discusses Kubernetes' ability to manage applications across multiple servers, ensuring high availability and reducing downtime through application replication. The script covers the basic architecture, including Masters and Workers, and introduces key components like the API server, controller manager, and scheduler. It also explains the concept of Pods, Services, and the use of declarative manifests for application deployment, highlighting Kubernetes' role in simplifying container management at scale.

Takeaways

😀 Kubernetes is a tool for managing containerized applications across multiple servers, simplifying deployment and scaling.
🔧 Docker is used to create containerized applications, ensuring they run the same way on any machine, avoiding 'it works on my machine' problems.
👨‍💻 Developers can focus on creating and modifying applications without needing to coordinate with system administrators for configuration.
🚀 Kubernetes was created by Google and is now open-source, allowing anyone to download, modify, and improve it.
🌐 Kubernetes solves the problem of managing a large number of containers across many nodes, providing high availability and reducing downtime.
🔄 High availability in Kubernetes is achieved by creating replicas of applications, ensuring traffic is redirected to functioning copies if one fails.
📈 Scalability is managed by Kubernetes, allowing for the creation of additional application copies to handle increased traffic or capacity needs.
🛠 Kubernetes architecture consists of two main groups: Masters and Workers, with the Masters running several components like the API server, controller manager, and scheduler.
📦 Pods in Kubernetes are sets of containers that share a network space and IP, typically running a single container each but can run more for task division.
🔗 An overlay network in Kubernetes allows pods to communicate across different nodes, facilitating inter-pod communication regardless of their location.
🌐 Services in Kubernetes provide a stable way to access applications, with different types like ClusterIP, NodePort, LoadBalancer, and Ingress to manage traffic.

Q & A

What is the main topic of the video?
-The main topic of the video is Kubernetes, explaining what it is, its purpose, and how it works.
What is Docker and how does it relate to Kubernetes?
-Docker is a tool that allows you to run applications in containers, ensuring that the application runs the same way on any machine. It is related to Kubernetes as Kubernetes is an orchestration tool for managing Docker containers across multiple servers.
What problem does Kubernetes solve that Docker does not?
-Kubernetes solves the problem of managing containers across many servers, providing high availability, scaling, and disaster recovery, which Docker does not handle on its own.
What is an orchestrator in the context of container management?
-An orchestrator is a tool that manages the deployment, scaling, and operations of application containers across a cluster of hosts.
Who originally created Kubernetes and what is its current status?
-Kubernetes was originally created by Google and is now an open-source project that anyone can download, use, and modify.
What does Kubernetes provide in terms of application management?
-Kubernetes provides high availability by creating replicas of applications, scaling capabilities to handle varying traffic, and disaster recovery through its declarative manifests.
What are the two main components of a Kubernetes architecture?
-The two main components of a Kubernetes architecture are the Masters and the Workers. The Masters manage the cluster, while the Workers run the applications in containers.
What is a Pod in Kubernetes and why are they considered volatile?
-A Pod in Kubernetes is a set of containers that share a network space and have a single IP. They are considered volatile because they can be destroyed and recreated during deployments, such as version updates.
What is a Service in Kubernetes and why is it used?
-A Service in Kubernetes is an abstraction that defines a logical set of Pods and a policy by which to access them. It is used to provide a stable endpoint for accessing the Pods, which are otherwise volatile.
What are some types of Services in Kubernetes?
-Some types of Services in Kubernetes include ClusterIP, NodePort, LoadBalancer, and Ingress, each providing different methods of accessing the Pods.
How does Kubernetes handle the creation and management of Pods?
-Kubernetes uses deployments, which are templates for creating Pods. When a deployment is applied to a Kubernetes cluster, the controller manager takes care of creating the Pods according to the template.

Outlines

00:00

📚 Introduction to Kubernetes

This paragraph introduces the topic of Kubernetes, explaining its purpose and basic functionality. It mentions that Kubernetes is a tool for managing containerized applications across multiple servers, ensuring high availability and scalability. The speaker compares it to Docker, which is used for running applications in containers but lacks the orchestration capabilities that Kubernetes provides. Kubernetes was created by Google and is now an open-source project, allowing anyone to download, modify, and improve it. The paragraph also touches on the high-level architecture of Kubernetes, including the roles of Masters and Workers, and the use of agents, the API server, controller manager, and scheduler within the system.

05:00

🔧 Deep Dive into Kubernetes Features and Architecture

The second paragraph delves deeper into Kubernetes' features, discussing its architecture and the components that make it function effectively. It explains the concept of Pods, which are groups of containers that share a network namespace and IP, and the volatility of Pods, which are destroyed and recreated during deployments. The paragraph also introduces Services in Kubernetes, which provide a stable entry point to access applications running in Pods, and mentions different types of services like ClusterIP, LoadBalancer, Ingress, and NodePort. The speaker emphasizes the use of declarative manifests for managing the state of the cluster, allowing for easy recovery and scaling of applications. The paragraph concludes with a mention of the practicality of running Kubernetes in various cloud environments and the ease of setting it up locally for practice.

Mindmap

Keywords

💡Kubernetes

Kubernetes is an open-source container orchestration system for automating application deployment, scaling, and management. It was originally designed by Google and is now maintained by the Cloud Native Computing Foundation. In the video, Kubernetes is presented as a solution to manage containers across multiple servers, providing high availability and reducing downtime by creating application replicas and handling traffic routing.

💡Containerization

Containerization refers to the process of packaging software into containers that can be run on any system without modification. In the script, Docker is mentioned as a tool for containerization, allowing applications to run with their environment and dependencies encapsulated within a container, ensuring consistent performance across different machines.

💡Orchestration

Orchestration in the context of the video refers to the automated management of containers across multiple servers. It is the process of coordinating the operation of containers to ensure they work together efficiently. Kubernetes serves as an orchestrator, handling tasks such as load balancing, scaling, and self-healing of containers.

💡High Availability

High availability is the property of a system being continuously operational for a desirable period. In the video, Kubernetes achieves high availability by creating multiple replicas of an application, ensuring that if one replica fails, the others can continue to serve the application without affecting the user experience.

💡Pods

In Kubernetes, a pod is the basic unit of deployment and scaling. It is a group of one or more containers that share the same network namespace and can communicate with each other. The script mentions that pods are volatile, meaning they are destroyed and recreated during deployment, and that they should not be directly addressed via IP for service access.

💡Services

Services in Kubernetes are abstractions that define a logical set of pods and a policy by which to access them. They provide a stable endpoint for accessing the application running in pods. The video script discusses different types of services, such as ClusterIP, NodePort, LoadBalancer, and Ingress, which offer various ways to expose an application to external traffic.

💡Deployment

A deployment in Kubernetes is a strategy to declare the desired state of a set of pods. It is used to manage the application's lifecycle, including creating, updating, and scaling the pods. The script explains that once a deployment is applied to a cluster, the controller manager in Kubernetes takes over to ensure the desired state is maintained.

💡Manifests

In Kubernetes, manifests are files that describe the desired state of the system's resources. They are used to create and manage resources declaratively. The video script mentions that Kubernetes uses manifests to define the deployment of applications, allowing for easy scaling and recovery of services.

💡Etcd

Etcd is a distributed key-value store that provides a reliable way to store data across a cluster of machines. In the context of Kubernetes, etcd is used to store the cluster state, including all configurations and the desired state of the system, ensuring consistency and persistence of the cluster's data.

💡API Server

The API server in Kubernetes is a component that exposes the Kubernetes API. It allows different clients, such as command-line tools, developer UIs, and third-party integrations, to interact with the cluster. The script mentions the API server as part of the master components that handle external interactions with the Kubernetes cluster.

💡Controller Manager

The controller manager in Kubernetes is responsible for running cluster controllers that watch the state of the cluster and ensure it matches the desired state. It is a key component that handles the reconciliation process, making sure that the actual state of the cluster aligns with the state defined in the manifests.

Highlights

Introduction to Kubernetes, explaining its purpose and how it differs from Docker and Docker Swarm.

Docker as a tool for running applications in a containerized manner, ensuring consistent application behavior across different environments.

The challenge of managing containers across multiple servers and the need for an orchestrator to handle this complexity.

Kubernetes as a container orchestration tool created by Google and now open-sourced for community contributions.

Kubernetes' primary function of managing containers across multiple nodes and providing high availability and reducing downtime.

The concept of creating application replicas in Kubernetes to ensure high availability and seamless traffic redirection in case of failures.

Kubernetes' ability to scale applications by creating additional copies to handle increased traffic or capacity needs.

The role of Kubernetes in disaster recovery, simplifying the process of recreating lost applications based on declarative manifests.

Overview of Kubernetes architecture, distinguishing between Masters and Workers, and the function of each component.

Explanation of 'kubelet', the Kubernetes agent that runs on each worker node.

The function of the API server in Kubernetes, which exposes an interface for various clients to interact with the cluster.

The role of the controller manager in monitoring the cluster and ensuring the correct number of containers are running.

The scheduler's responsibility for placing pods based on the instructions from the controller manager.

The use of etcd as the database for storing the state and configurations of the Kubernetes cluster.

Definition and explanation of 'pods' in Kubernetes, which are sets of containers sharing a network namespace.

The volatility of pods and the process of creating new ones during deployment updates.

Introduction to Kubernetes services, which provide a stable entry point to access applications running in pods.

Different types of Kubernetes services, such as ClusterIP, NodePort, LoadBalancer, and Ingress, and their respective use cases.

The importance of Kubernetes' declarative manifests for defining and managing application deployment templates.

Practical advice on when to use Kubernetes in a business environment based on the scale and needs of the operation.

Availability of various Kubernetes providers and the ease of running Kubernetes with the support of cloud services like Digital Ocean, Google Cloud, and Amazon.

A personal account of using Kubernetes in a large-scale operation with approximately 3,000 servers running 100 pods each.

Comparison between using Kubernetes and managing containers with OpenStack's LXD, highlighting the impracticality of the latter for production environments.