DevFest 2020 - Introduction to Kubernetes

DevFest 2020 - Introduction to Kubernetes

Transcript

1. Introduction to Kubernetes Idowu Emehinola DevOps Engineer, Deimos
2. What is Kubernetes?
3. Kubernetes (K8s) is an open-source container orchestration system for automating deployment, scaling, and management of containerized applications.
4. Okay? What does that even mean?
5. Let’s take a few step backwards.
6. Containers
7. Infrastructure (hardware) Operating System Libraries Dependencies
8. Infrastructure (hardware) Operating System Libraries Dependencies Hardware Compatibility
9. Infrastructure (hardware) Operating System Libraries Dependencies OS Compatibility + Hardware Compatibility
10. Infrastructure (hardware) Operating System Libraries Dependencies Libs and Deps Compatibility + OS Compatibility + Hardware Compatibility
11. Infrastructure (hardware) Operating System Libraries Dependencies Compatibility HELL
12. Infrastructure (hardware) Operating System Docker Libs Deps Libs Deps Libs Deps Libs Deps Containers
13. Containers A Container can be said to be a Virtual Machine (VM) but instead of running in a predefined operating system, they run using your defined operating System.
14. Containers VS Virtual Machines Infrastructure (hardware) Operating System Hypervisor OS Libs Deps Application OS Libs Deps Application Virtual Machine Virtual Machine Infrastructure (hardware) Operating System Docker Libs Deps Application Libs Deps Application Container Container CPU Utilization Disk Space Boot up time CPU Utilization Disk Space Boot up time
15. What Next? How do we run it in production? What if our container depends on other containers? How do we manage that? When number of user increase, how do we scale up (or down)? When a container crashes, how do we spin up a new one IMMEDIATELY?
16. Container Orchestration
17. Kubernetes Kubernetes (K8s) is an open-source container orchestration system for automating deployment, scaling, and management of containerized applications.
18. Basic Concept - Node A Node is a machine (physical or virtual) which several kubernetes components are installed. It is a worker machine where containers launched by kubernetes would be running in.
19. What if your node fails? Some weird reasons
20. Basic Concept - Cluster
21. Basic Concept - Master Node
22. POD A POD is a single instance of an application. A POD is the smallest object, that can created in kubernetes. POD
23. API version a "Pod" can be found. Object type to deploy Labels are used to "Identify" pods in the kubernetes cluster Name of the Pod Name of the Container running in the Pod Docker Image to run in the container
24. What happens when your POD fails?
25. ReplicaSet A ReplicaSet’s purpose is to maintain a stable set of replica Pods running at any given time. As such, it is often used to guarantee the availability of a specified number of identical Pods. POD POD RELICASET
26. API version for ReplicaSet Labels the ReplicaSet uses to filter and find it's Pods Labels are used to "Identify" this replicaSet in the kubernetes cluster Name of ReplicaSet Everything here is similar to the configuration of a pod except the "name" attribute. How many pods to run - how many instance of this application should be running at any given time
27. POD POD POD POD POD POD v1 v2 UPGRADE ROLLING UPDATES ROLLBACK REPLICA SET
28. POD POD POD POD POD POD REPLICA SET v1 v2 UPGRADE ROLLING UPDATES ROLLBACK DEPLOYMENT
29. Deployment Deployment which is a kubernetes object that comes higher in the hierarchy (relative to pod and replicaset). A deployment provides us with capabilities to upgrade the underlying application instances seamlessly.
30. © Deimos Cloud (Pty) Ltd Name of deployment Label to identify Deployment resource in the cluster Defines the strategy used to replace old Pods by new ones Labels used to filter and identify pods. Labels used to target this pod Name of the container running in the pod. Docker Image Environment variable to use in the application e.g: PORT => 8000 PORT application is runs on. How many pods to run - how many instance of this application should be running at any given time
31. POD POD
32. POD POD SERVICE
33. Service A Service is a kubernetes object that enables communication between various deployment within the cluster and It can also enable users to communicate with applications running on kubernetes.
35. Ingress An Ingress is an API object that manages external access to the services in a cluster, typically HTTP. It may provide load balancing, SSL termination and name-based virtual hosting. It acts like a "smart router" that routes to different service depending on the domain configure. It can be considered as a smart Loadbalancer.
36. What are Load-balancers?
37. Loadbalancer A Loadbalancer helps to efficiently distribute incoming network traffic across a multiple instances of an application (or servers).
38. Internet APP (web server) User
39. Internet APP 1 APP 1 User Load Balancer APP 1
40. Ingress vs Loadbalancers Service test.example.com example.com/api example.com/videos another-domain.com INGRESS Service Service Service Service LoadBalancer Traffic Traffic POD POD POD POD POD POD POD POD POD POD
42. ConfigMaps ConfigMaps are used to pass configuration data in the form of key value pairs in Kubernetes.
44. Secrets Secrets are used to store sensitive information, like passwords or keys. They are similar to configMaps, except that they are stored in an encoded or hashed format.
46. Summary - Compatibility Hell - Containers - Containers vs VMs - Container Orchestration - Node / Master Node - Cluster - Kubernetes - Pod - ReplicaSet - Deployment - Service - Ingress - ConfigMaps - Secrets
47. Thank you for Listening. Questions?