Kubernetes is a container cluster manager that aims to provide a platform for automating deployment, scaling, and operations of application containers across clusters of machines. It uses pods as the basic building block, which are groups of application containers that share storage and networking resources. Kubernetes includes control planes for replication, scheduling, and services to expose applications. It supports deployment of multi-tier applications through replication controllers, services, labels, and pod templates.
Kubernetes Interview Questions And Answers | Kubernetes Tutorial | Kubernetes...Edureka!
( Kubernetes Certification Training: https://www.edureka.co/kubernetes-certification )
This Edureka tutorial on "Kubernetes Interview Questions" will help you crack interviews on various Kubernetes related roles in the industry. The different types of questions included in this session are:
1. Basic Kubernetes Interview Questions
2. Kubernetes Architecture-Based Interview Questions
3. Scenario-Based Interview Questions
4. Multiple Choice Questions
DevOps Tutorial Blog Series: https://goo.gl/P0zAfF
** Kubernetes Certification Training: https://www.edureka.co/kubernetes-cer... **
This Edureka tutorial on "Kubernetes Networking" will give you an introduction to popular DevOps tool - Kubernetes, and will deep dive into Kubernetes Networking concepts. The following topics are covered in this training session:
1. What is Kubernetes?
2. Kubernetes Cluster
3. Pods, Services & Ingress Networks
4. Case Study of Wealth Wizards
5. Hands-On
DevOps Tutorial Blog Series: https://goo.gl/P0zAfF
Next-Generation Cloud Native Apps with Spring Cloud and KubernetesVMware Tanzu
SpringOne 2021
Session Title: Next-Generation Cloud Native Apps with Spring Cloud and Kubernetes
Speaker: Ryan Baxter, Staff Software Engineer at VMware
Kubernetes Interview Questions And Answers | Kubernetes Tutorial | Kubernetes...Edureka!
( Kubernetes Certification Training: https://www.edureka.co/kubernetes-certification )
This Edureka tutorial on "Kubernetes Interview Questions" will help you crack interviews on various Kubernetes related roles in the industry. The different types of questions included in this session are:
1. Basic Kubernetes Interview Questions
2. Kubernetes Architecture-Based Interview Questions
3. Scenario-Based Interview Questions
4. Multiple Choice Questions
DevOps Tutorial Blog Series: https://goo.gl/P0zAfF
** Kubernetes Certification Training: https://www.edureka.co/kubernetes-cer... **
This Edureka tutorial on "Kubernetes Networking" will give you an introduction to popular DevOps tool - Kubernetes, and will deep dive into Kubernetes Networking concepts. The following topics are covered in this training session:
1. What is Kubernetes?
2. Kubernetes Cluster
3. Pods, Services & Ingress Networks
4. Case Study of Wealth Wizards
5. Hands-On
DevOps Tutorial Blog Series: https://goo.gl/P0zAfF
Next-Generation Cloud Native Apps with Spring Cloud and KubernetesVMware Tanzu
SpringOne 2021
Session Title: Next-Generation Cloud Native Apps with Spring Cloud and Kubernetes
Speaker: Ryan Baxter, Staff Software Engineer at VMware
Persistent Storage with Containers with Kubernetes & OpenShiftRed Hat Events
Manually configuring mounts for containers to various network storage platforms and services is tedious and time consuming. OpenShift and Kubernetes provides a rich library of volume plugins that allow authors of containerized applications (Pods) to declaratively specify what the storage requirements for the containers are so that OpenShift can dynamically provision and allocate the storage assets for the specified containers. As the author of the Kubernetes Persistent Volume specification, I will provide an overview of how Persistent Volume plugins work in OpenShift, demo block storage and file storage volume plugins and close with the Red Hat storage roadmap.
Presented at LinuxCon/ContainerCon by Mark Turansky, Principal Software Engineer, Red Hat
Mark Turansky is a Principal Software Engineer at Red Hat and a full-time contributor to the Kubernetes Project. Mark is the author of the Kubernetes Persistent Volume specification and a member of the Red Hat OpenShift Engineering team.
Checking in your deployment configuration as code
Helm is a tool that streamlines the creation, deployment and management of your Kubernetes-native applications. In this talk, we take a look at how Helm enables you to manage your deployment configurations as code, and demonstrate how it can be used to power your continuous delivery (CI/CD) pipeline.
Video: https://youtu.be/C_u4_l84ED8
Karl Isenberg reviews the history of distributed computing, clarifies terminology for layers in the container stack, and does a head to head comparison of several tools in the space, including Kubernetes, Marathon, and Docker Swarm. Learn which features and qualities are critical for container orchestration and how you can apply this knowledge when evaluating platforms.
Idea to Production - with Gitlab and KubernetesSimon Dittlmann
Setting up a continuous delivery pipeline form scratch with gitlab.com and Kubernetes (Google Container Service GKE) on Google Cloud Platform.
The entire source code is available at https://github.com/Pindar/gcloud-k8s-express-app
Blog post https://www.itnotes.de/gitlab/kubernetes/k8s/gke/gcloud/2017/03/05/idea-to-production-with-gitlab-and-kubernetes/
Kubernetes Basis: Pods, Deployments, and ServicesJian-Kai Wang
Kubernetes is a container management platform and empowers the scalability to the container. In this repository, we address the issues of how to use Kubernetes with real cases. We start from the basic objects in Kubernetes, Pods, deployments, and Services. This repository is also a tutorial for those with advanced containerization skills trying to step into the Kubernetes. We also provide several YAML examples for those looking for quickly deploying services. Please enjoy it and let's start the journey to Kubernetes.
DockerCon 2022 - From legacy to Kubernetes, securely & quicklyEric Smalling
You’ve been developing software for years and now your team is ready to take the plunge into orchestrated containers and Kubernetes. You’ve learned about containers, images, and Dockerfiles, but standing up a Kubernetes cluster and actually running your app in it seems like a daunting task.
In this session, we’ll go over the basics to get your app up and running in Kubernetes right on your own workstation using Docker Desktop. On the way, we’ll cover some of the security aspects you need to keep in mind and show you how to implement them in your Kubernetes manifests.
We’ll go over:
1.) Kubernetes basics, including pods, deployments, and services
2.) Moving a legacy app into a container and running it in Kubernetes
3.) Some security best practices to watch out for — and what can happen if you don’t
4.) Implementing those best practices to defend against and limit the blast radius of an attack
K8s in 3h - Kubernetes Fundamentals TrainingPiotr Perzyna
Kubernetes (K8s) is an open-source system for automating deployment, scaling, and management of containerized applications. This training helps you understand key concepts within 3 hours.
Get you Java application ready for Kubernetes !Anthony Dahanne
In this demos loaded talk we’ll explore the best practices to create a Docker image for a Java app (it’s 2019 and new comers such as Jib, CNCF buildpacks are interesting alternatives to Docker builds !) - and how to integrate best with the Kubernetes ecosystem : after explaining main Kubernetes objects and notions, we’ll discuss Helm charts and productivity tools such as Skaffold, Draft and Telepresence.
Docker Essentials Workshop— Innovation Labs July 2020CloudHero
This presentation was the foundation of our Docker Essentials workshop hosted by CloudHero CEO & founder Andrei Manea for the Innovation Labs team on the 23rd of July 2020.
This presentation covers the following topics:
-Getting started with containers
-A bit of history about orchestration
-Introduction to services (what they are, how to create and scale them).
To find out more about this topic, check https://cloudhero.io/
Kubernetes is designed to be an extensible system. But what is the vision for Kubernetes Extensibility? Do you know the difference between webhooks and cloud providers, or between CRI, CSI, and CNI? In this talk we will explore what extension points exist, how they have evolved, and how to use them to make the system do new and interesting things. We’ll give our vision for how they will probably evolve in the future, and talk about the sorts of things we expect the broader Kubernetes ecosystem to build with them.
Persistent Storage with Containers with Kubernetes & OpenShiftRed Hat Events
Manually configuring mounts for containers to various network storage platforms and services is tedious and time consuming. OpenShift and Kubernetes provides a rich library of volume plugins that allow authors of containerized applications (Pods) to declaratively specify what the storage requirements for the containers are so that OpenShift can dynamically provision and allocate the storage assets for the specified containers. As the author of the Kubernetes Persistent Volume specification, I will provide an overview of how Persistent Volume plugins work in OpenShift, demo block storage and file storage volume plugins and close with the Red Hat storage roadmap.
Presented at LinuxCon/ContainerCon by Mark Turansky, Principal Software Engineer, Red Hat
Mark Turansky is a Principal Software Engineer at Red Hat and a full-time contributor to the Kubernetes Project. Mark is the author of the Kubernetes Persistent Volume specification and a member of the Red Hat OpenShift Engineering team.
Checking in your deployment configuration as code
Helm is a tool that streamlines the creation, deployment and management of your Kubernetes-native applications. In this talk, we take a look at how Helm enables you to manage your deployment configurations as code, and demonstrate how it can be used to power your continuous delivery (CI/CD) pipeline.
Video: https://youtu.be/C_u4_l84ED8
Karl Isenberg reviews the history of distributed computing, clarifies terminology for layers in the container stack, and does a head to head comparison of several tools in the space, including Kubernetes, Marathon, and Docker Swarm. Learn which features and qualities are critical for container orchestration and how you can apply this knowledge when evaluating platforms.
Idea to Production - with Gitlab and KubernetesSimon Dittlmann
Setting up a continuous delivery pipeline form scratch with gitlab.com and Kubernetes (Google Container Service GKE) on Google Cloud Platform.
The entire source code is available at https://github.com/Pindar/gcloud-k8s-express-app
Blog post https://www.itnotes.de/gitlab/kubernetes/k8s/gke/gcloud/2017/03/05/idea-to-production-with-gitlab-and-kubernetes/
Kubernetes Basis: Pods, Deployments, and ServicesJian-Kai Wang
Kubernetes is a container management platform and empowers the scalability to the container. In this repository, we address the issues of how to use Kubernetes with real cases. We start from the basic objects in Kubernetes, Pods, deployments, and Services. This repository is also a tutorial for those with advanced containerization skills trying to step into the Kubernetes. We also provide several YAML examples for those looking for quickly deploying services. Please enjoy it and let's start the journey to Kubernetes.
DockerCon 2022 - From legacy to Kubernetes, securely & quicklyEric Smalling
You’ve been developing software for years and now your team is ready to take the plunge into orchestrated containers and Kubernetes. You’ve learned about containers, images, and Dockerfiles, but standing up a Kubernetes cluster and actually running your app in it seems like a daunting task.
In this session, we’ll go over the basics to get your app up and running in Kubernetes right on your own workstation using Docker Desktop. On the way, we’ll cover some of the security aspects you need to keep in mind and show you how to implement them in your Kubernetes manifests.
We’ll go over:
1.) Kubernetes basics, including pods, deployments, and services
2.) Moving a legacy app into a container and running it in Kubernetes
3.) Some security best practices to watch out for — and what can happen if you don’t
4.) Implementing those best practices to defend against and limit the blast radius of an attack
K8s in 3h - Kubernetes Fundamentals TrainingPiotr Perzyna
Kubernetes (K8s) is an open-source system for automating deployment, scaling, and management of containerized applications. This training helps you understand key concepts within 3 hours.
Get you Java application ready for Kubernetes !Anthony Dahanne
In this demos loaded talk we’ll explore the best practices to create a Docker image for a Java app (it’s 2019 and new comers such as Jib, CNCF buildpacks are interesting alternatives to Docker builds !) - and how to integrate best with the Kubernetes ecosystem : after explaining main Kubernetes objects and notions, we’ll discuss Helm charts and productivity tools such as Skaffold, Draft and Telepresence.
Docker Essentials Workshop— Innovation Labs July 2020CloudHero
This presentation was the foundation of our Docker Essentials workshop hosted by CloudHero CEO & founder Andrei Manea for the Innovation Labs team on the 23rd of July 2020.
This presentation covers the following topics:
-Getting started with containers
-A bit of history about orchestration
-Introduction to services (what they are, how to create and scale them).
To find out more about this topic, check https://cloudhero.io/
Kubernetes is designed to be an extensible system. But what is the vision for Kubernetes Extensibility? Do you know the difference between webhooks and cloud providers, or between CRI, CSI, and CNI? In this talk we will explore what extension points exist, how they have evolved, and how to use them to make the system do new and interesting things. We’ll give our vision for how they will probably evolve in the future, and talk about the sorts of things we expect the broader Kubernetes ecosystem to build with them.
JDO 2019: Tips and Tricks from Docker Captain - Łukasz LachPROIDEA
This session covers a bunch of tips and tricks for getting the most out of Docker. The tips were inspired by suggestions, blogs, and presentations and everyday challenges encountered by other Docker Captains but also the members of the Docker community. Come and see the unobvious and unexpected in terms of orchestration, image creation and management, also networking and volumes!
A small introduction to get started on Kubernetes as a user. This explains the main concepts like pod, deployment and services and gives some hints to help you use kubectl command.
These slides were presented in Grenoble Docker meetup in November 2017.
Open Source Summit 2018, Vancouver (Canada): Workshop by Josef Adersberger (@adersberger, CTO at QAware) and Michael Frank (Software Architect at QAware)
Abstract:
Istio service mesh is a thrilling new tech that helps getting a lot of technical stuff out of your microservices (circuit breaking, observability, mutual-TLS, ...) into the infrastructure - for those who are lazy (aka productive) and want to keep their microservices small. Come one, come all to the Istio playground:
(1) We provide an overview of all current Istio features on a YAML and CLI level.
(2) We guide you through the installation of Istio on a local Kubernetes cluster.
(3) We bring a small sample application.
(4) We provide assistance in the case you get stuck ... and it's up to you to explore and tinker with Istio on your own paths and with your own pace.
*** Please find prerequisites and content here: https://github.com/adersberger/istio-playground ***
The Nova driver for Docker has been maturing rapidly since its mainline removal in Icehouse. During the Juno cycle, substantial improvements have been made to the driver, and greater parity has been reached with other virtualization drivers. We will explore these improvements and what they mean to deployers. Eric will additionally showcase deployment scenarios for the deployment of OpenStack itself inside and underneath of Docker for powering traditional VM-based computing, storage, and other cloud services. Finally, users should expect a preview of the planned integration with the new OpenStack Containers Service effort to provide automation of advanced containers functionality and Docker-API semantics inside of an OpenStack cloud.
Note that the included Heat templates are NOT usable. See the linked Heat resources for viable templates and examples.
Francisco Javier Ramírez Urea - IT Architect, Hoplasoftware
Guillaume Morini - SE, Docker
The integration of Kubernetes orchestration into the Docker Enterprise Platform presents deployments with interesting new abstractions for application connectivity. Devs and Ops are often challenged with rationalizing how pod networking (with CNI plugins like Calico or Flannel), Services (via kube-proxy) and Ingress work in concert to enable application connectivity within and outside a cluster. Similarly, given the dynamic and transient nature of containerized microservice workloads, how to leverage scalable and declarative approaches like network policies to express segmentation and security primitives. This session provides an illustrative walkthrough of these core concepts by going through common deployment architectures providing design, operations, and scale considerations based on experience from numerous production deployments. We will discuss Kubernetes publishing methods and deep dive into Ingress Controllers. This session will also showcase how to complement application and operations workflows with policy-driven business, compliance and security controls typically required in enterprise production deployments including going further into limiting traffic to services, session persistence, rewriting, and activating container health checks.
Kubernetes is exploding in popularity right now and has all the buzz and cargo-culting that Docker enjoyed just a few years ago. But what even is Kubernetes? How do I run my PHP apps in it? Should I run my PHP apps in it ?
Water billing management system project report.pdfKamal Acharya
Our project entitled “Water Billing Management System” aims is to generate Water bill with all the charges and penalty. Manual system that is employed is extremely laborious and quite inadequate. It only makes the process more difficult and hard.
The aim of our project is to develop a system that is meant to partially computerize the work performed in the Water Board like generating monthly Water bill, record of consuming unit of water, store record of the customer and previous unpaid record.
We used HTML/PHP as front end and MYSQL as back end for developing our project. HTML is primarily a visual design environment. We can create a android application by designing the form and that make up the user interface. Adding android application code to the form and the objects such as buttons and text boxes on them and adding any required support code in additional modular.
MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software. It is a stable ,reliable and the powerful solution with the advanced features and advantages which are as follows: Data Security.MySQL is free open source database that facilitates the effective management of the databases by connecting them to the software.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
4. | Page
Docker?
Going back in time , most applications were deployed directly on physical hardware.
● Single userspace.
● Shared runtime env between applications.
● Hardware resources generally underutilized.
5. | Page
To overcome the limitation of shared runtime env ,
underutilized resources and more. The IT industry
adopted virtualization with hypervisor such as KVM
, ESX and more.
Docker?
6. | Page
Moving from VM => “Virtual OS” :
● We removed the hypervisor layer to reduce
complexity.
● The containers approach is to package each application
with all dependencies runtime environment.
● We have different application running on the same
host and isolated using the containers technology.
Docker?
8. | Page
Docker: Application centric.
● A clean, safe, portable runtime environment for your app.
● No more worries about missing dependencies, packages
and other pain points during deployments.
● Run each app in its own isolated container (fs , cgroup ,
pid etc ….)
● Easy to pack into a box and super portable.
Build once... (finally) run anywhere*
Docker?
9. | Page
Docker’s architecture
● Docker uses client server architecture.
● server: running the Docker daemon.
● Client: communicate with the server via sockets or RESTful API .
● Docker registry: public or private stores from which the server upload or download images
● The client can run on any host.
11. | Page
The name Kubernetes originates from Greek, meaning
“helmsman” or “pilot””(WiKi).
A helmsman or helm is a person who steers a ship, sailboat, submarine...
Kubernetes - κυβερνήτης
12. | Page
More facts:
● Originated at Google (Borg).
● Supports multiple cloud and bare-metal environments
● Supports multiple container runtimes (Docker , rkt)
● 100% Open source, written in Go
● k8s is an abbreviation derived by replacing the 8 letters “ubernete” with 8.
Manage containerized applications , not machines.
Kubernetes ?
Kubernetes is a container cluster manager. It aims to provide a
"platform for automating deployment, scaling, and operations of
application containers across clusters of machines.
13. | Page
Deploy single tier single container APP is “easy”
Deploying a complex multi tier APP is more difficult
● One or more containers.
● replication of containers.
● Persistent storage.
Deploying lots of complex APPs (microservices) can be a challenge.
More Info...
Why kubernetes ?
14. | Page
Control Plane
Node Controller
Replication Controller
Endpoints Controller
Service Account
Token Controllers
And more...`
architecture
15. | Page
A node is a physical or virtual machine
running Kubernetes, onto which pods
can be scheduled.
Node
operating system
kubelet
kube-proxy
k8s
16. | Page
Kubectl - get (Display one or many resources)
1. List kubernetes nodes.
kubectl get nodes
kubectl get nodes --context=kube-aws
DEMO
17. | Page
Pod is a Small group of co-located containers with optionally shared
volume between the containers.
Pods are the basic deployment unit in Kubernetes.
● Shared namespace
○ Share IP address , localhost
○ Every pod gets a unique IP
● Managed Lifecycle
○ Bound to a node , in place restart
○ Cannot move between nodes
Pod(po)
18. | Page
Pod(po) - yaml manifest
apiVersion: v1
kind: Pod
metadata:
labels:
phase: prod
role: frontend
name: myfirstpod
name: myfirstpod
spec:
containers:
- name: filepuller
image: sliranc/filepuller:latest
volumeMounts:
- mountPath: /usr/share/nginx/html
name: static-vol
- name: webserver
image: nginx:latest
ports:
- containerPort: 80
volumeMounts:
- mountPath: /usr/share/nginx/html
name: static-vol
volumes:
- name: static-vol
emptyDir: {}
Spec: is the specification of the
desired state of an object.
kind: System object resource
Examples: Pod, RC, Service etc...
19. | Page
kubectl
1. Create pod myfirstpod by filename.
kubectl create -f myfirst-pod.yaml
kubectl create -f myfirst-pod.yaml --context kube-aws
2. List pods.
kubectl get pods
kubectl get pods --context=kube-aws
DEMO
20. | Page
Label are key / value pairs - object metadata
● Label are attached to pods , services , rc or almost any other objects in k8s
● Can be used to organize or select subset of object.
● queryable by selectors
labels:
app: rcweb
phase: production
role: frontend
http://kubernetes.io/docs/user-guide/labels/
Labels
21. | Page
Label selector - query object using labels
● Can identify a set of objects
● Group a set of objects
● Used in svc and rc to select the monitored watched objects
replication controller selector example:
selector:
app: rcweb
phase: production
Selectors
22. | Page
direct traffic to pods
Defines a logical set of pods and a policy by which
to access them.
● are abstraction on top of the pods (LB)
● use selector to create the logical set of pods.
● Gets a stable virtual IP and Port.
● Cluster IP are only available inside k8s
services (svc)
Can define:
● What the 'internal' IP should be.(ClusterIP)
● What the 'external' IP should be. (NodePort , LoadBalancer)
● What port the service should listen on.
24. | Page
services (svc) - yaml manifest
apiVersion: v1
kind: Service
metadata:
name: myweb
spec:
ports:
- port: 80 # the port that this service should serve on.
# (e.g. 'www') or a number (e.g. 80)
targetPort: 80
protocol: TCP
# just like the selector in the replication controller,
# but this time it identifies the set of pods to load balance
traffic to.
selector:
name: myfirstpod
System object resource
Examples: Pod, RC, Service etc...
Spec is the specification of the
desired state of an object.
labels:
phase: prod
role: frontend
name: myfirstpod
26. | Page
Service Iptables mode:
Node X
Pod
Client A
Cluster IP(VIP)
Client B
Kube-Proxy
Kubelet
NodePort NodePort
Kube-Proxy
Pod 1 Pod 2 Pod 3
Iptables
27. | Page
Replication controller == pods supervisor
Ensures that a specified number of pod "replicas"
are running at any given time:
● Too many pods will trigger pods termination.
● Too few pods will trigger new pods creation.
● Main Goal = Replicas: x current / x desired.
replication controller will monitor all the pods
defined in the label selector.
replication controller (rc) ReplicaSet (rs)
ReplicationController
replica: 4
name: rcweb
selector:
app: rcweb
phase: production
28. | Page
apiVersion: v1
kind: ReplicationController
metadata:
name: rcweb
labels:
name: rcweb
spec:
replicas: 2
# selector identifies the set of pods that this replication controller is responsible for managing
selector:
app: rcweb
phase: production
# template defines the 'cookie cutter' used for creating new pods when necessary
template:
metadata:
labels:
app: rcweb
role: frontend
phase: production
name: rcwebpod
spec:
containers:
- name: staticweb
image: sliranc/rcweb:latest
Pod
Template
replication controller (rc) - yaml manifest
29. | Page
replication controller (rc) ReplicaSet
master
Node 1 Node 2
Replication controller
replica: 3
name: rcweb
selector:
app: rcweb
Phase: production
Pod 2
label:
app:rcweb
phase:production
Pod 1
label:
app:rcweb
phase:production
Pod 3
label:
app:rcweb
phase:production
Pod X
label:
app:my-app
phase:alpha
30. | Page
kubectl
1. create all resources in a directory.
kubectl create -f rcweb
kubectl get pods -l app=rcweb
kubectl describe svc/rcweb
kubectl rolling-update rcweb --image=sliranc/rcweb:v2 --update-period="10s"
DEMO
32. | Page
ConfigMap & Secrets
● ConfigMap is a resource available in kubernetes for managing
application configuration. The goal is to decouple the app
configuration from the image content in order to keep the
container portable and k8s agnostic.
● ConfigMap are key value pairs of configuration data.
http://kubernetes.io/docs/user-guide/configmap/
kind: ConfigMap
apiVersion: v1
metadata:
name: default-app
data:
db-host: MYDB
apiVersion: v1
kind: Pod
metadata:
name: test-default-app
spec:
containers:
- name: test-defaultapp
image:sliranc/rcweb
env:
- name: DB_HOST
valueFrom:
configMapKeyRef:
name: default-app
key: db-host
35. | Page
emptyDir
emptyDir is a temporary directory that
shares a pod's lifetime.
● Storage provider = Local host
● Files will be erased on pod deletion.
● Mounted by containers inside the pod.
emptyDir path on node:
/var/lib/kubelet/pods/<id>/volumes/kubernetes.io~empty-dir/<volume_name>
volumes:
- name: static-vol
emptyDir: {}
36. | Page
hostPath
hostPath is a bare host directory volume.
● Acts as data volume in Docker.
● Containers can RW files on localhost.
● There is no control on quota.
Volumes:
- name: static-vol
hostPath:
path: /target/path/on/host
37. | Page
PersistentVolume
Kubernetes provides
abstraction for volumes using
PersistentVolume (PV).
User - Claim PV using (PVC) persistentVolumeClaim
(pvc001 , pvc002)
PersistentVolume(PV)
nfs awsElasticBlockStore
rbdgcePersistentDisk
PersistentVolumeClaim(PVC)
Pod1 Pod2 Pod3
Admin - Creates pool of PVs (pv0001 , pv0002)
volumes:
- name: my-vol
persistentVolumeClaim:
claimName: "pvc001"
38. | Page
Multi tenancy in kubernetes.
● A single cluster should be able to satisfy the needs of multiple users or
groups of users.
Each user community has its own:
1. resources (pods, services, replication controllers, etc.)
2. policies (who can or cannot perform actions in their community)
3. constraints (this community is allowed this much quota, etc.)
Kubernetes starts with two initial namespaces:
default - The default namespace for objects with no other namespace.
kube-system - The namespace for objects created by the Kubernetes system
Namespaces
42. | Page
DNS
● The DNS add-on allows your services to have a DNS name
in addition to an IP address. This is helpful for simplified
service discovery between applications.
*As of Kubernetes 1.3, DNS is a built-in service launched automatically using the addon manager cluster add-on
43. | Page
Monitoring - Heapster
● Heapster enables monitoring and performance analysis in Kubernetes
Clusters. Heapster collects signals from kubelets(cadvisor) and the api
server, processes them, and exports them...
Heapster
sink
Data
push
Query
Master (API)Node (Kubelet)
48. | Page
DEMO
kubectl - describe
(Show details of a specific resource or group of resources)
1. describe a pod (po)
kubectl describe pod/myfirstpod
2. describe a service (svc) - check Endpoints
kubectl describe svc/myweb
3. describe a node
kubectl describe node/ctor-knb002
49. | Page
kubectl - logs (Print the logs for a container in a pod)
1. create logme pod from url.
kubectl create -f https://raw.githubusercontent.
com/sliranc/k8s_workshop/master/cli_demo/logme-pod.
yaml
2. Print the logs of a pod with one container
kubectl logs logme
3. stream the logs
kubectl logs -f logme
4. print the logs of a container filepuller in pod myfirstpod
kubectl logs myfirstpod -c filepuller
DEMO
50. | Page
kubectl - exec
(Execute a command in a container)
1. Inject bash to a single pod container
kubectl exec -it logme bash
ps -auxwww
exit
2. Inject bash to a multi container pod
kubectl exec -it myfirstpod -c webserver bash
ps -auxwww
exit
DEMO
51. | Page
kubectl
(Edit a resource from the default editor)
1. Edit ReplicationController
kubectl edit rc/rcweb
Restart pods
2. kubectl port-forward - forwards connections to a port on a pod
kubectl port-forward myfirstpod 8888:80
curl http://localhost:8888
DEMO
52. | Page
RedisSlave
Guestbook - DEMO
Deploy multi tier web_app - Guestbook
frontend - Pod
SVC - frontend
frontend - Pod
Pod
RedisMaster
SVC
RedisMaster
SVC
RedisSlave
Pod
RedisSlave
https://github.com/kubernetes/kubernetes/tree/master/examples/guestbook
53. | Page
Guestbook - DEMO
1. Create the replication controller for frontend
kubectl create -f gb-frontend-rc.yaml
2. Create the service for frontend
kubectl create -f gb-frontend-svc.yaml
3. Create the redis-master replication controller
kubectl create -f redis-master-rc.yaml
4. Create the service for redis-master
kubectl create -f redis-master-svc.yaml
5. Create the redis-slave replication controller
kubectl create -f redis-slave-rc.yaml
6. Create the service for redis-master
kubectl create -f redis-slave-svc.yaml
7. Get the external url for svc and browse to the website.
kubectl describe svc frontend
8. Delete all pods
Kubectl delete ...
9. Scale your rc
kubectl scale ...
10. Delete all resources svc , rc
DEMO
54. | Page
Pod Health checks
Liveliness Readiness
On failure Kill container Stop sending traffic to pod
Check types Http , exec , tcpSocket Http , exec , tcpSocket
Declaration example
(Pod.yaml)
livenessProbe:
failureThreshold: 3
httpGet:
path: /healthz
port: 8080
readinessProbe:
httpGet:
path: /status
port: 8080
55. | Page
Kubernetes - Proxies
1. Api-proxy
kubectl cluster-info
<kubernetes_master_address>/api/v1/proxy/namespaces/<namespace_name>/services/<service_name>[:port_name]
http://qtvr-kma01:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard
1. kubectl proxy - proxies from a localhost address to the apiserver
kubectl proxy
http://localhost:8001/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard
2. Kube-proxy - proxies UDP and TCP - provides load balancing.
63. | Page
kubectl - kubernetes client.
1. Looking for Help...
kubectl help
Use "kubectl help [command]" for more information about a command
2. Version - get the server and client version.
kubectl version
3. Cluster info
kubectl cluster-info
*Display urls of the master and services(*api proxy) with label kubernetes.io/cluster-service=true
65. | Page
kubectl - create
1. Create a resource by filename.
kubectl create -f myfirst-pod.yaml
2. create all resources in a directory.
kubectl create -f rcweb
3. create a resource from stdin.
cat myfirst-svc.yaml | kubectl create -f -
4. create a resource from url.
kubectl create -f https://raw.githubusercontent.
com/sliranc/k8s_workshop/master/cli_demo/logme-pod.yaml
66. | Page
kubectl - get (Display one or many resources)
1. List all types of resource to get.
kubectl get
2. List all pods
kubectl get pods
3. List all pods in wide format
kubectl get pods -o wide
4. Display specific pod in yaml format
kubectl get pod/myfirstpod -o yaml
67. | Page
kubectl - get (Display one or many resources)
1. Query for pod with specific label
kubectl get pod -l name=rcwebpod
2. List all pods and services
kubectl get pods,svc
3. List all nodes (no)
kubectl get nodes
68. | Page
kubectl - describe
(Show details of a specific resource or group of resources)
1. List all types of resource to describe.
kubectl describe
2. describe a pod (po)
kubectl describe pod/myfirstpod
3. describe a service (svc)
kubectl describe svc/myweb
browse to LoadBalancer Ingress of the service http://ingress...
4. describe a node
kubectl describe node/<use one from the get nodes output>
69. | Page
kubectl - logs (Print the logs for a container in a pod)
1. Print the logs for pod with one container
kubectl logs logme
2. stream the logs
kubectl logs -f logme
3. print the logs of a container filepuller in pod myfirstpod
kubectl logs myfirstpod -c filepuller
HW : check out the -p flag for logs.
70. | Page
kubectl - scale
(Set a new size for a Replication Controller)
1. Scale rc rcweb to 3 replicas
kubectl get pods -l name=rcwebpod
kubectl scale --replicas=3 rc rcweb
kubectl get pods -l name=rcwebpod
2. Scale only if the current replication is X
kubectl scale --current-replicas=3 --replicas=2 rc rcweb
kubectl get pods -l name=rcwebpod
71. | Page
kubectl - exec
(Execute a command in a container)
1. Inject bash to a single pod container
kubectl exec -it logme bash
ps -auxwww
exit
2. Inject bash to a multi container pod
kubectl exec -it myfirstpod -c webserver bash
ps -auxwww
exit
72. | Page
kubectl - rolling-update
(Set a new size for a Replication Controller)
1. Get the service ingress and browse to http://ingress……..
kubectl describe svc/rcweb
2. upgrade your rc to new rc with 10s delay between pod.
kubectl rolling-update rcweb --image=sliranc/rcweb:v2 --update-
period="10s"
Refresh your browser.
kubectl get pods -l name=rcwebpod
73. | Page
kubectl edit
(Edit a resource from the default editor)
1. Edit the number of replicas
kubectl edit rc rcweb
kubectl get pods -l name=rcwebpod
74. | Page
kubectl - delete
(Delete a resource by filename, stdin, resource and name, or by resources and label selector)
1. Delete resource by file
kubectl delete -f myfirst-pod.yaml
2. Delete resource by name
kubectl delete svc myweb rcweb
3. Delete all pods
kubectl delete pods --all
4. Delete rc by name
kubectl delete rc rcweb
75. | Page
kubectl - delete
(Delete a resource by filename, stdin, resource and name, or by resources and label selector)
1. Delete resource by file
kubectl delete -f myfirst-pod.yaml
2. Delete resource by name
kubectl delete svc myweb rcweb
3. Delete all pods
kubectl delete pods --all
4. Delete rc by name
kubectl delete rc rcweb
76. | Page
Docker images
● Docker images are the basis of
containers.
● Docker images are read-only
templates we use for creating
containers.
● Docker images are multilayer.
● docker images are highly portable
and can be shared.
77. | Page
External source such as DB (headless service)
Web - Pod
SVC - Web
Web - Pod
App - Pod
SVC - App
App - Pod
SVC - DB
External DATA store