NUS-ISS Learning Day 2018- Deploying a microservices app using docker and kubernetes
- 1. Deploy and Manage Containers on K8S http://bit.ly/docker_k8s_talk Prasanna Veerapandi (bala) bala@nus.edu.sg
- 2. About me Now - Lecturer at Institute of System Science - Creates and teaches - Python For Data, Ops and Things - Cloud DevOps Foundation - Containers for Deploying and Scaling Apps Past - Application consultant - Web Application development & DevOps - Mobile Application Developer
- 3. Objective Introduction to containers from a Developer’s perspective
- 4. What is a container ?
- 5. Virtual Machines Server Host OS Hypervisor (type 2) Guest OS Run time App #0 Guest OS Run time App #0 Guest OS Run time App #1 Virtualmachines VMs virtualizes the hardware
- 6. Containers Server Linux LXC Runtime App #0 App #0 Run time App #1 Virtualmachines Container VMs virtualizes the hardware Container virtualizes Linux Server Host OS Hypervisor (type 2) Guest OS Run time App #0 Guest OS Run time App #0 Guest OS Run time App #1
- 7. LXC Enabling Technologies Namespaces - isolation - Virtualizes Linux resources (process, network, filesystem, etc) for one or more processes - Analogy: Java packages, XML namespaces CGroups - resource limits - Hard and soft limit on resources eg. CPU shares, memory, bandwidth, etc Overlay filesystem - bottom of the well view - Provides a unified view of multiple directories by transparently overlaying and merging them
- 9. Docker Container Server Linux LXC Runtime App #0 App #0 Run time App #1 A set of LXC management tools for creating “containerize” application - Application running in their own namespaces - Their own view of the the file systems - Constrained to a specific set of resources An “image” format
- 10. Let’s Code A simple web server using NodeJS and Express
- 11. Cloning and Customizing the App - Create an application directory - Copy the files over to the new directory - package.json - application manifest - Files and directories - (Re)Install the required libraries - Customize the content
- 12. Containerize It Applications’ files node Dockerfile docker build -t myapp:latest . myapp
- 13. Run It Applications’ files node Dockerfile docker run -d -p 3000:3000 --name app0 myapp:latest myapp
- 14. Docker Workflow App image Running deploy build push Container registry pull deploy
- 15. Space and Volumes - Containers are ephemeral - Any files you create in the container will be gone once you remove the container - Mapping host directory into the container - Sharing of common data - Creating and saving artifacts - Mapping a container’s volume into another container - Data only container eg database - Mapping storages into a container - Data from NFS, other drives
- 16. Volumes VOLUME /myapp/public /data docker run -d -v /data:/myapp/public -p 3000:3000 --name app0 myapp:latest Mounted under /myapp/public
- 18. Growing Big The picture can't be displayed. Servers with Docker Loadbalancer The picture can't be displayed. The picture can't be displayed. The picture can't be displayed.
- 19. But… Need to setup environment Deal with hardware and software failures Keeping services up and monitoring them Build a infrastructure framework to deal with deployments …
- 20. The picture can't be displayed. The picture can't be displayed. The picture can't be displayed. The picture can't be displayed. The picture can't be displayed. “Ops” Servers “Dev” Applications The picture can't be displayed.
- 21. Or you can use
- 22. What is Kubernetes? A container cluster management system - Manage Docker, rkt Support applications by providing the following - scaling/replication, load balancing, rolling updates, health checks, services discovery, etc. Alternatives - Docker Swarm, Mesos Marathon, Fleet
- 23. Kubernetes Architecture (vastly simplified)The picture can't be displayed. The picture can't be displayed. The picture can't be displayed. Kubernetesnodes Kuberneres Master Kublet kubectl
- 24. POD - a deployable unit of container(s) localhost:3306 MySQL database Payara Application Server NodeJS
- 25. Deployment kubectl run deployment/kapps --image=chukmunnlee/kapps:latest --port=3000 Creates and schedules a pod onto a node in the cluster The picture can't be displayed.The picture can't be displayed. The picture can't be displayed. 3000
- 27. Services kubectl expose deployment/kapps --port=8080 --target-port=3000 Provides location and referential transparency by providing a stable IP address The picture can't be displayed.The picture can't be displayed. The picture can't be displayed. 3000 8080
- 28. Scaling kubectl scale deployment/kapps --replicas=3 Replication controller resolves differences between declared and actual The picture can't be displayed.The picture can't be displayed. The picture can't be displayed. 3000 8080 3000 3000
- 29. Pet vs Sheep/Cattle Vertical scaling Horizontal scaling