What is Kubernetes | Kubernetes explained in 15 mins
Summary
TLDREl video presenta una explicación detallada de Kubernetes, un framework de orquestación de contenedores open source desarrollado por Google. Cubre su definición, la problemática que resuelve, su arquitectura básica con nodos maestros y worker, y los componentes clave como pods, contenedores, servicios y cómo se configuran. Destaca las funcionalidades de alta disponibilidad, escalabilidad y recuperación ante desastres que ofrecen las herramientas de orquestación de contenedores como Kubernetes.
Takeaways
- 📚 Kubernetes es un marco de orquestación de contenedores de código abierto, originalmente desarrollado por Google.
- 🔄 Solve problemas de gestión de cientos o miles de contenedores en diferentes entornos como máquinas físicas, máquinas virtuales o entornos de nube.
- 🤖 Garantiza alta disponibilidad, escalabilidad y recuperación ante desastres para las aplicaciones.
- 🌐 La arquitectura básica de Kubernetes consiste en al menos un nodo maestro y varios nodos de trabajo, donde los nodos de trabajo ejecutan contenedores de aplicaciones.
- 🔧 El nodo maestro ejecuta procesos clave como el servidor de API, el gerente de controladores y el programador.
- 💾 etcd es un componente crucial que almacena la configuración y el estado actual del clúster de Kubernetes.
- 🌐 La red virtual permite que todos los nodos del clúster se comuniquen entre sí y se conviertan en una máquina poderosa.
- 📦 Un Pod (unidad de implementación) es la unidad más pequeña en Kubernetes, que puede contener múltiples contenedores.
- 🔄 Los Pods son componentes efímeros y pueden morir con frecuencia, lo que justifica el uso de servicios para proporcionar direcciones IP permanentes.
- 🛠 La configuración de Kubernetes se realiza a través del servidor de API y se maneja en formato YAML o JSON.
- 🔄 Kubernetes trabaja de forma declarativa,力求达到用户声明的期望状态.
Q & A
¿Qué es Kubernetes?
-Kubernetes es un marco de orquestación de contenedores de código abierto, originalmente desarrollado por Google, que ayuda a gestionar aplicaciones compuestas por cientos o quizás miles de contenedores en diferentes entornos como máquinas físicas, máquinas virtuales o entornos en la nube.
¿Qué problemas resuelve Kubernetes?
-Kubernetes resuelve problemas relacionados con la gestión de una gran cantidad de contenedores en múltiples entornos, garantizando la alta disponibilidad, escalabilidad y recuperación ante desastres de las aplicaciones.
¿Qué es una arquitectura básica de Kubernetes?
-Una arquitectura básica de Kubernetes consiste en al menos un nodo maestro conectado a varios nodos de trabajo (worker nodes), donde se ejecutan los contenedores de las aplicaciones y se distribuye la carga de trabajo.
¿Qué procesos esenciales se ejecutan en el nodo maestro de Kubernetes?
-El nodo maestro ejecuta procesos esenciales como el API server (punto de entrada para la comunicación con el clúster), el controller manager (mantiene un registro de los eventos del clúster), el scheduler (responsible de programar contenedores en nodos de trabajo) y el etcd (almacena el estado actual del clúster).
¿Qué es un pod en Kubernetes?
-Un pod es la unidad más pequeña de configuración y interacción en Kubernetes, actuando como un contenedor que encapsula uno o varios contenedores. Los pods son componentes de Kubernetes que gestionan los contenedores en su interior sin intervención directa del usuario.
¿Cómo se comunican los pods en Kubernetes?
-Los pods en Kubernetes se comunican a través de direcciones IP internas asignadas a cada pod, permitiendo que los contenedores dentro de los pods se comuniquen entre sí a través de estas direcciones IP.
¿Qué es un servicio en Kubernetes y cuál es su función?
-Un servicio en Kubernetes es un componente que proporciona una dirección IP permanente para la comunicación entre los pods, actuando como un equilibrador de carga y permitiendo que las aplicaciones se comuniquen sin interrupciones a pesar de los pods que se reinician y obtengan nuevas direcciones IP.
¿Cómo se configuran los componentes de Kubernetes como los pods y servicios?
-La configuración de los componentes en Kubernetes se realiza a través del API server, donde los clientes de Kubernetes (como la interfaz de usuario, scripts o herramientas de línea de comando) envían solicitudes de configuración en formato YAML o JSON.
¿Qué es la orquestación de contenedores y por qué es necesaria?
-La orquestación de contenedores es una tecnología que automatiza la implementación, escalabilidad, monitoreo y mantenimiento de aplicaciones que se ejecutan en contenedores. Es necesaria debido al aumento del uso de microservicios y la complejidad de gestionar cientos o miles de contenedores en múltiples entornos.
¿Qué sucede si un nodo maestro de Kubernetes falla?
-Si un nodo maestro de Kubernetes falla, se requiere una copia de seguridad para poder acceder al clúster de nuevo. En entornos de producción, se recomienda tener al menos dos nodos maestros para garantizar la continuidad del clúster en caso de fallo.
¿Cómo Kubernetes garantiza la alta disponibilidad de las aplicaciones?
-Kubernetes garantiza la alta disponibilidad mediante la replicación de pods, la supervisión constante del estado de los contenedores y la reconstrucción automática de los contenedores que fallen, asegurando así que las aplicaciones permanezcan accesibles para los usuarios.
Outlines
📚 Introducción a Kubernetes
Este párrafo inicia explicando qué es Kubernetes, su definición oficial y su funcionamiento básico. Se menciona que Kubernetes es un marco de orquestación de contenedores open source desarrollado originalmente por Google, capaz de gestionar aplicaciones compuestas por cientos o miles de contenedores en diferentes entornos como máquinas físicas, máquinas virtuales o entornos cloud. Además, se discuten los problemas que Kubernetes resuelve, como la alta disponibilidad, escalabilidad y recuperación ante desastres, y se presenta un caso de estudio para entender mejor la necesidad de tecnologías de orquestación de contenedores.
🖥️ Arquitectura Básica de Kubernetes
En este párrafo se describe la arquitectura básica de un clúster Kubernetes, compuesto al menos por un nodo maestro y varios nodos de trabajo. Cada nodo ejecuta un proceso 'kubelet' que permite la comunicación y ejecución de tareas. Los nodos de trabajo alojan contenedores de aplicaciones diferentes, y el nodo maestro ejecuta procesos esenciales como el API server (punto de entrada para el clúster), el controlador manager y el scheduler. También se destaca el rol del almacenamiento etcd para mantener el estado actual del clúster y la red virtual que permite a los nodos comunicarse como una sola máquina virtual.
📦 Conceptos Básicos de Kubernetes: Pods y Contenedores
Este párrafo cubre los conceptos fundamentales de Kubernetes, como los pods y los contenedores. Un pod es la unidad mínima de configuración y es un contenedor que puede incluir varios contenedores, generalmente uno por aplicación. Los pods son efímeros y pueden reiniciarse frecuentemente, lo que lleva a la introducción del concepto de 'service', que proporciona una dirección IP permanente y actúa como un equilibrador de carga para los pods. La explicación incluye cómo los clientes de Kubernetes interactúan con el API server para configurar componentes como pods y servicios.
🔧 Creación y Configuración de Componentes Kubernetes
Finalmente, se explica cómo se crean y configuran los componentes de Kubernetes, como los pods y los servicios, a través de solicitudes de configuración hechas por clientes a través del API server. Se da un ejemplo de cómo se configura un deployment con replica sets de pods y se destaca el enfoque declarativo de las solicitudes, donde se define el resultado deseado y Kubernetes trabaja para alcanzar ese estado. Esto garantiza que, incluso si un pod falla, Kubernetes lo reemplace y mantenga el clúster en el estado deseado.
Mindmap
Keywords
💡Kubernetes
💡Contenedores
💡Orquestación de Contenedores
💡Maestro (Master Node)
💡Trabajo (Worker Node)
💡Pods
💡Servicios (Services)
💡Alta Disponibilidad
💡Escalabilidad
💡Recuperación ante desastres
💡etcd
Highlights
Kubernetes is an open-source container orchestration framework developed by Google.
It manages containers, such as Docker, in various environments like physical machines, VMs, or cloud setups.
Kubernetes helps manage applications composed of hundreds or thousands of containers.
The rise of microservices increased the use of container technologies due to their suitability for small, independent apps.
Container orchestration tools like Kubernetes address the complexity of managing numerous containers across different environments.
Kubernetes ensures high availability, scalability, and disaster recovery for applications.
A Kubernetes cluster consists of at least one master node and multiple worker nodes, each running a kubelet process.
Worker nodes host Docker containers of different applications, depending on the workload distribution.
The master node runs essential Kubernetes processes like the API server, controller manager, and scheduler.
etcd key-value storage holds the Kubernetes cluster's configuration and status data, enabling backup and restore from snapshots.
A virtual network connects all nodes within the Kubernetes cluster, turning them into a single, resourceful entity.
Pods are the smallest unit in Kubernetes, acting as wrappers for containers and housing multiple containers per application.
Each pod is assigned its own IP address, allowing for internal communication within the cluster.
Pods are ephemeral and can die frequently; Kubernetes automatically restarts stopped containers within pods.
Services in Kubernetes provide a stable IP address and load balancing for pods, overcoming the challenge of dynamic IP addresses.
Kubernetes configurations are declarative, defining the desired state for the system to achieve and maintain.
The API server is the entry point for all configuration requests in the Kubernetes cluster.
Kubernetes deployment is a template for creating pods, allowing for the specification of replicas, container images, and environment variables.
Transcripts
so in this video I'm going to explain
what kubernetes is we're going to start
off with the definition to see what
official definition is and what it does
then we're going to look at the problem
solution case study of Cabezas basically
why did kubernetes even come around and
what problems does it solve we're gonna
look at the basic architecture what are
the master nodes and the slave nodes and
what are the kubernetes processes that
actually make up the platform mechanism
then we going to see some basic concepts
and the components of kubernetes which
are pots and containers and services and
what is the role of each one of those
components and finally we going to look
at a simple configuration that you as a
kubernetes cluster user would use to
create those components and configure
the cluster to your needs so let's jump
in right into the definition what is
kubernetes so kubernetes is an open
source container orchestration framework
which was originally developed by google
so on the foundation it manages
containers be docker containers or from
some other technology which basically
means that kubernetes helps you manage
applications that are made up of
hundreds or maybe thousands of
containers and it helps you manage them
in different environments like physical
machines virtual machines or cloud
environments or even hybrid deployment
environments so what problems does
kubernetes solve and what are the tasks
of a container orchestration tool
actually so to go through this
chronologically the rise of micro
services cause increased usage of
container technologies because the
containers actually offer the perfect
host for small independent applications
like Microsoft a nurse and the micro
service technology actually resulted in
applications that they're now comprised
of hundreds or sometime
maybe even thousands of containers now
managing those loads of containers
across multiple environments using
scripts and self-made tools can be
really complex and sometimes even
impossible so that specific scenario
actually caused the need for having
container orchestration technologies so
what those orchestration tools like
kubernetes do is actually guarantee
following features one is high
availability in simple words high
availability means that the application
has no downtime so it's always
accessible by the users a second one is
scalability which means that application
has a high performance it loads fast and
users have a very high response rates
from the application and the third one
is disaster recovery which basically
means that if an infrastructure has some
problems like data is lost or the
server's explode or something bad
happens with the server center the
infrastructure has to have some kind of
mechanism to pick up the data and to
restore it to the latest state so that
application doesn't actually lose any
data and the containerized application
can run from the latest stayed after the
recovery and all of these are
functionalities that container
orchestration technologies like
kubernetes offer
so how does the kubernetes basic
architecture actually look like the
kubernetes cluster is made up with at
least one master node and then connected
to it you have a couple of worker nodes
where each node has a cubelet process
running on it and cubelet is actually a
kubernetes process that makes it
possible for the cluster to talk to each
other to communicate to each other and
actually execute some tasks on those
nodes like running application processes
each worker node has docker containers
of different applications deployed on it
so depending on how the workload is
distributed you would have different
number of docker containers running on
worker nodes and worker nodes are where
the actual work is happening so here is
where where your applications are
running so the question is what is
running on master node master node
actually runs several kubernetes
processes that are absolutely necessary
to run and manage the cluster properly
one of such processes is an API server
which also is a container an API server
is actually the entry point to the
kubernetes cluster so this is the
process which the different kubernetes
clients will talk to like UI if you're
using kubernetes dashboard an API if
you're using some scripts and automating
technologies and a command-line tool so
all of these will talk to the API server
another process that is running on
master node is a controller manager
which basically keeps an overview of
what's happening in the cluster whether
something needs to be repaired or maybe
if a container died and it needs to be
restarted etc and another one is
scheduler which is basically responsible
for scheduling containers on different
nodes based on the workload and the
available server resources on each node
so it's an intelligent process that
decides on which worker node the next
container should be scheduled on
based on the available resources on
those worker notes and the load that
that container meets and another very
important component of the whole cluster
is actually an etcd
key value storage which basically holds
at any time the current state of the
kubernetes cluster so it has all the
configuration data inside and all the
status data of each node and each
container inside of that node and the
backup and restore that we mentioned
previously is actually made from these
etcd snapshots because you can recover
the whole cluster state using that etcd
snapshot and last but not least also a
very important component of kubernetes
which enables those notes
worker notes master notes talk to each
other is the virtual network that spends
all the notes that are part of the
cluster and in simple words virtual
network actually turns all the notes
inside of the cluster into one powerful
machine that has the sum of all the
resources of individual notes one thing
to be noted here is that work who knows
because they actually have most load
because they are running the
applications on inside of it usually are
much bigger and have more resources
because they will be running hundreds of
containers inside of them where is
master node will be running just a
handful of master processes like we see
in this diagram so it doesn't need that
many resources however as you can
imagine master node is much more
important than the individual worker
notes because if for example you lose a
master node excess you will not be able
to access the cluster anymore and that
means that you absolutely have to have a
backup of your master at any time so in
production environments usually you
would have at least two masters inside
of your kubernetes cluster but in more
cases of course you're going to have
multiple masters where if one master
node is down the cluster continues to
function smoothly because you have other
masters available so now
look at some kubernetes basic concepts
like pots and containers in kubernetes
pod is the smallest unit that you as a
kubernetes user will configure and
interact with in pod is basically a
wrapper of a container and on each
worker node you're gonna have multiple
pods and inside of a pod you can
actually have multiple containers
usually per application you would have
one pod so the only time you would need
more than one containers inside of a pod
is when you have a main application that
needs some helper containers so usually
you would have one pod per application
so a database for example would be one
pod a message broker will be another pod
a server will be again another pod in
Europe no J's application for example or
a java application will be its own pod
and as we mentioned previously as well
there is a virtual network dispense the
kubernetes cluster so what that does is
that it assigns each pod its own IP
address so each pod is its own self
containing server with its own IP
address and the way that they can
communicate with each other is we using
that internal IP addresses and to note
here we don't actually configure or
create containers inside of kubernetes
cluster but we only work with the pods
which is an abstraction layer over
containers and pod is a component of
kubernetes that manages the containers
running inside itself without our
intervention so for example if a
container stops or dies inside of a pod
it will be automatically restarted
inside of the pod however pods are
ephemeral components which means that
pots can also die very frequently and
when a pod dies a new one gets created
and here is where the notion of service
comes into play so what happens is that
whenever a pod gets restarted or weak
a new pod is created and it gets a new
IP address so for example if you have
your application talking to a database
pod using the IP address the pods have
and the pod restarts it gets a new IP
address obviously it would be very
inconvenient but just that IP address
all the time so because of that another
component of Cabrini's called service is
used which basically is an alternative
or a substitute to those IP addresses so
instead of having this dynamic IP
addresses their services sitting in
front of each pod that talk to each
other so now if a pod behind the service
dies and gets recreated the service
stays in place because their life cycles
are not tied to each other and the
service has two main functionalities one
is an IP address so it's a permanent IP
address which you can use to communicate
with between the pods and at the same
time it is a load balancer
so now that we have seen the basic
concepts of kubernetes how do we
actually create those components like
pods and services to configure the
kubernetes cluster all the configuration
in kubernetes cluster actually goes
through a master node with the process
called API server which we mentioned
briefly earlier so kubernetes clients
which could be a UI a kubernetes
dashboard for example or an API which
could be a script or curl command or a
command line tool like cube CTL they all
talk to the API server and they send
their configuration requests to the API
server which is the main entry point or
the only entry point into the cluster in
this requests have to be either in
yellow format or JSON format and this is
how a example configuration in the ML
format actually looks like so with this
we are sending a request to kubernetes
to configure a component called
deployment which is basically a template
or a blueprint for creating pots and in
this specific configuration example we
tell kubernetes to create to replica
pots for us called my app with each pod
replica having a container based on my
image running inside in addition to that
we configure what the environment
variables and the port configuration of
this container inside of the pot should
be and as you see the configuration
requests in kubernetes our declarative
form so we declare what is our desired
outcome from kubernetes and kubernetes
tries to meet those requirements meaning
for example since we declare we want to
replica pots of my app deployment to be
running in the cluster and one of those
pots dies the controller manager will
see that the east and shoot states now
are different the actual state is one
part our desired state is two so it goes
to work to make sure that this desired
state is recovered automatically
restarting the second replica of that
pot and this is how kubernetes
configuration works with all of its
component
be the parts or the services or
deployments what have you thanks for
watching the video I hope it was helpful
and if it was don't forget to like it if
you want to be notified whenever a new
video comes out then subscribe to my
channel if you have any questions if
something wasn't clear in the video
please post them in a comment section
below and I will try to answer them so
thank you and see you in the next video
تصفح المزيد من مقاطع الفيديو ذات الصلة
Application Virtualization on IBM Fusion HCI
Amazon AWS LightSail. Trabajar con contenedores
What is OpenShift | techbeatly
Containers vs VMs: What's the difference?
Proveedores de servicios en la nube | Diferencias entre AWS, AZURE y GCP
#AzureFundamentals 2020 | Fundamentos de Cosmos DB con Matías Quaranta
5.0 / 5 (0 votes)