Docker and Microservice
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The document discusses Docker and microservices, explaining that Docker is an implementation of container technology that allows for the creation and management of lightweight, isolated application environments. It highlights the benefits of using Docker, such as improved resource efficiency and easier application deployment, as well as the concepts of microservices as a modular approach to software design compared to monolithic systems. Additionally, it provides practical examples of Docker usage, configuration, and integration with microservices, along with references to more detailed resources.
![SAMPLE DOCKERFILE
FROM ubuntu:16.04
# Set up Redis
RUN apt-get update
RUN DEBIAN_FRONTEND=noninteractive apt-get -y install redis-server redis-
tools
# Run Redis and expose port
EXPOSE 6379
ENTRYPOINT [ "/usr/bin/redis-server" ]
CMD []](https://image.slidesharecdn.com/dockerandmicroservice-160818035214/85/Docker-and-Microservice-15-320.jpg)
![MICROSERVICE DOCKERFILE
FROM java:8
VOLUME /tmp
ADD users-microservice-0.1.0.jar app.jar
RUN bash –c 'touch /app.jar'
EXPOSE 9000
ENTRYPOINT [ "java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]](https://image.slidesharecdn.com/dockerandmicroservice-160818035214/85/Docker-and-Microservice-37-320.jpg)
![RUN DOCKER-MACHINE ON AWS
$ # Launch Docker machine on AWS EC2
$ vi ~/.aws/credentials
$ cat ~/.aws/credentials
[default]
aws_access_key_id = AKIXXXXXXXXXXXXX
aws_secret_access_key =
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
$ # Launch an AWS EC2 t2.large instance in us-west-2 zone
$ docker-machine create --driver amazonec2 --amazonec2-region us-west-2 --
amazonec2-instance-type t2.large docker-aws](https://image.slidesharecdn.com/dockerandmicroservice-160818035214/85/Docker-and-Microservice-40-320.jpg)
![TEST THE APPLICATIONS
$ # Run Eureka – API gateway/router
$ open $(echo "$(echo $DOCKER_HOST)"|
sed 's/tcp:///http:///g'|
sed 's/[0-9]{4,}/8761/g'|
sed 's/"//g')
$ # Run the movie API – this should register all the microservices
$ curl $(echo "$(echo $DOCKER_HOST)/movie"|
sed 's/tcp:///http:///g'|
sed 's/[0-9]{4,}/10000/g'|
sed 's/"//g')](https://image.slidesharecdn.com/dockerandmicroservice-160818035214/85/Docker-and-Microservice-42-320.jpg)
Docker and Microservice
- 1. DOCKER AND MICROSERVICE What is this Docker and Microservice thing that everyone is talking about?
- 2. YOU BUILD IT, YOU RUN IT “The best way to completely automate operations is to have to developers be responsible for running the software they develop. It is painful at times, but also means considerable creativity gets applied to a very important aspect of the software stack. It also brings developers into direct contact with customers and a very effective feedback loop starts. There is no separate operations department at Amazon: you build it; you run it. Werner Vogels, CTO Amazon – 2006
- 3. HOST ARCHITECTURE How to run an application?
- 4. Infrastructure • Can be a computer, cluster of computers, or the Cloud • Abstract users from servers and infrastructure • There’s a server but it’s hidden from you
- 5. SINGLE HOST • Shared resources • No user space (app) isolation • Fairly tight coupling of operating system and applications
- 6. VIRTUAL MACHINE • Better user space (app) isolation • Not very resource efficient • Slower • Guest OS can be different from the host OS
- 7. CONTAINER VIRTUALIZER • Better user space (app) isolation • Not as strong as that of VM • Lightweight • Operating system virtualization • Base OS
- 8. WHAT IS DOCKER? • Container = isolated (user space) sandbox • Docker = Container implementation • Benefits • Lightweight • Faster to launch
- 10. INFRASTRUCTURE AS CODE Code your infrastructure
- 11. CONTAINER TECH Existed for years in Linux
- 12. Docker (the company) just figured a clever way to packaging it and adding a rich toolset around it.
- 13. DOCKER INTERNALS • Docker runs on Linux x64 (only) • Dependent on libcontainer, a Linux container platform • Container isolation: filesystem, process, network • Layered filesystem • Benefits • Versioning • Portability
- 14. DOCKER WORKFLOW Dockerfile Docker Client docker build Image Docker Client docker run Container Docker Client docker pull docker push Docker Registry
- 15. SAMPLE DOCKERFILE FROM ubuntu:16.04 # Set up Redis RUN apt-get update RUN DEBIAN_FRONTEND=noninteractive apt-get -y install redis-server redis- tools # Run Redis and expose port EXPOSE 6379 ENTRYPOINT [ "/usr/bin/redis-server" ] CMD []
- 16. DOCKER IMAGE AND LAYERED FILESYSTEM • Docker image is a read-only template and is used to create containers • Docker image consists of filesystems layered on top of each other • Docker uses Union File Systems UFS to build an image • Any update to an image adds a new layer instead of rebuilding the entire image • Container = images + top writable layer • Images are shared across different containers
- 17. BASE IMAGE SIZES Reference: https://www.brianchristner.io/docker-image-base-os-size-comparison/ 188 187 172 125 8 5 2 0 50 100 150 200 Ubuntu Fedora CentOS Debian Cirros Alpine BusyBox 6.50M 1.20M 1.20M 3.30M .02M .04M 2.50M .00M 1.00M 2.00M 3.00M 4.00M 5.00M 6.00M 7.00M Ubuntu Fedora CentOS Debian Cirros Alpine BusyBox Size (MB) # Download s (Popularity )
- 18. DOCKER ON MAC AND WINDOWS Running Docker on your Workstation
- 19. DOCKER ON MAC • Let’s focus on running Docker on the Mac • Remember Docker only runs on Linux x64 • How do I run it on the Mac? • Need Virtual Machine to emulate a Linux host • Virtual machine (VM) running Linux x64 • Docker engine running on VM • Mac client to communicate with Docker engine on Linux VM
- 20. DOCKER FOR MAC VS DOCKER TOOLBOX Docker for Mac Docker Toolbox # VMs 1 Multiple Underlying VM Hypervisor.framework (xhyve) VirtualBox Base OS Alpine Boot2Docker (VM) Management Tool Docker.app docker-machine (VM) Management UI GUI CLI
- 22. DOWNLOAD https://www.docker.com/products/docker-toolbox https://docs.docker.com/docker-for-mac/ Or $ brew cask install dockertoolbox
- 24. USE CASE • Web application running Ruby on Rails • Common website root directory • 1 Container running Ruby on Rails • 1 Container running Nginx • Connection to database • 1 Container running Postgres
- 25. DOCKER VOLUME • Volume can be created and mounted for more than 1 container to share resources • Put the website root folder in the volume • Persist data • Volume isn’t Union Filesystems, it exists as the host’s filesystem
- 26. DOCKER LINKING • Docker linking relies on the Container names • Launch your Docker container with names • Link the 2 Docker containers via the parameter --link • Docker establishes a secure tunnel between the container • Does not expose any ports • Does expose environment variables and /etc/hosts
- 27. DOCKER COMPOSE • Before Compose there was Fig • 1 configuration file = Compose file • Use the configuration file to define and launch multiple Docker containers • It basically helps you to organize and configure your multiple Docker container instances
- 28. DOCKER CLUSTERING TOOL • There are some great tools that you can use to elegantly manage multiple containers at scale • Large scale coordination • Service discovery • Automatic failover • Examples • Swarm • Kubernetes • Mesos
- 30. WHAT IS A MONOLITHIC SYSTEM Reference: https://github.com/kbastani/spring-cloud-microservice-example
- 31. EXTENDING THE MONOLITHIC Reference: https://github.com/kbastani/spring-cloud-microservice-example
- 34. DEMO Tying together what we have learned so far
- 36. PROJECT ORGANIZATION • docker • docker-compose.yml • XXX-microservice • src/main • docker • Dockerfile • pom.xml • pom.xml
- 37. MICROSERVICE DOCKERFILE FROM java:8 VOLUME /tmp ADD users-microservice-0.1.0.jar app.jar RUN bash –c 'touch /app.jar' EXPOSE 9000 ENTRYPOINT [ "java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]
- 38. CLONE THE PROJECT $ # Clone the project $ git git@github.com:kbastani/spring-cloud-microservice-example.git $ # Install prerequisites to build project $ brew cask install java $ brew install maven
- 39. RUN DOCKER-MACHINE ON LOCAL VM $ # Launch Docker machine, set the VM RAM to 6GB $ docker-machine create --driver virtualbox --virtualbox-memory 6144 default $ docker-machine env $ eval "$(docker-machine env default)" $ docker-machine ls NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS default * virtualbox Running tcp://192.168.99.100:2376 v1.12.0
- 40. RUN DOCKER-MACHINE ON AWS $ # Launch Docker machine on AWS EC2 $ vi ~/.aws/credentials $ cat ~/.aws/credentials [default] aws_access_key_id = AKIXXXXXXXXXXXXX aws_secret_access_key = XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX $ # Launch an AWS EC2 t2.large instance in us-west-2 zone $ docker-machine create --driver amazonec2 --amazonec2-region us-west-2 -- amazonec2-instance-type t2.large docker-aws
- 41. BUILD $ # Build Java application and Docker images $ docker images $ mvn clean install $ docker images $ cd docker $ less docker-compose.yml # Take a peek at the compose config file $ docker-compose up
- 42. TEST THE APPLICATIONS $ # Run Eureka – API gateway/router $ open $(echo "$(echo $DOCKER_HOST)"| sed 's/tcp:///http:///g'| sed 's/[0-9]{4,}/8761/g'| sed 's/"//g') $ # Run the movie API – this should register all the microservices $ curl $(echo "$(echo $DOCKER_HOST)/movie"| sed 's/tcp:///http:///g'| sed 's/[0-9]{4,}/10000/g'| sed 's/"//g')
- 43. DOCKER IS A DEPLOYABLE UNIT You build it, you run it with Docker. Developer now has the freedom to develop and deploy services.
- 44. Q + A Any questions? You can find me at @cybersam
- 45. REFERENCE • Docker Toolbox - https://www.docker.com/products/docker-toolbox • Docker Documentation - https://docs.docker.com/ • Pros and Cons of Microservices - https://smartbear.com/learn/api-design/what-are- microservices/ • Spring Cloud Microservice Example - https://github.com/kbastani/spring-cloud-microservice- example
- 46. CREDITS • Based on the Quintus template on Slides Carnival - http://www.slidescarnival.com/quintus-free-presentation- template/1405
Editor's Notes
- #4: Let’s start with the basics!
- #5: When I took the course Operating System, we learned the term hardware. Since then the industry has changed and what was called hardware then has now been abstracted to be known as infrastructure, which covers hardware, cluster of nodes, and the Cloud. In general the 4 key abstraction layers of running an application are: Application Operating System Kernel Infrastructure The following are the 3 basic hosting models.
- #7: In a virtual machine, the guest OS and host OS run in own kernel and the guest OS communicates with the actual infrastructure through the hypervisor. This mode is usually slower and due to hardware emulation.
- #8: In this virtualization mode, multiple isolated user space instance runs on the same kernel. These isolated user space are containers and they share the host kernel. Essentially Docker uses resource isolation feature of the Linux kernel eg. cgroups and kernel namespaces to allow containers to run within a single Linux instance.
- #9: Docker is an implementation of Container.
- #12: Google has been using their own container for years. In Open-source land, Linux has LXC and Libcontainer, BSD has jails, Solaris has Zones.
- #14: Before we jump to code, it would be good to understand the internals of Docker. This way we can understand how Docker code gets executed in a Docker Container.
- #15: To use docker all you need are these 4 commands: docker build docker pull docker push docker run
- #17: Namespace provides the container a view of the underlying system. Network Process ID Mount User Cgroup manages the resources eg. CPU, memory, network Union file system (UFS) Benefits of UFS Avoid duplicating a layer Incremental addition to the image via layer
- #20: Due to the time constraint, let’s focus on the Mac. It used to be a pain to get Docker working on the Mac. Things have improved but it can still be confusing. I hope to help you navigate through the Docker ecosystem on the Mac.
- #21: The key difference between the 2 is how you manage your VM. Both Docker for Mac and Docker Toolbox can coexist. But verdict is still out there. I would say try using one of the solutions for now. Docker for Mac is seamless, you launch Docker.app from the GUI and you run your docker client just like you would on a Linux host.
- #22: Let’s talk about running Docker on the Mac. To run Docker you need Docker toolbox. Because we need to Linux to run Docker, we need to launch Linux virtual machines from which we load Docker containers. Good news is that Docker (the company) makes all this easy. Doocker toolbox is based on boot2docker, which is 1 part Linux distro that the VM will load to run Docker and 1 part management tool. Boot2Docker Linux distro is super light and uses ~27MB and boots in 5s.
- #25: Here’s a good use case. There are applications that may consist of multiple containers. Here is a good use case: a Rails web application. We have 1 container running Rails and another container running nginx. But the files that the 2 containers use are shared and need to be in a common root directory.
- #27: Through Docker Volume, you share resources between multiple containers. But what if you need a container to communicate with another container? This is where Docker Link comes in. Run your Docker container with a name – names are unique. Eg. docker run –d –P –name web training/webapp python app.py Run a docker and link it to the other container Note: There’s also port mapping that Docker containers can use to connect to one another.
- #28: Running multiple Docker containers can get hairy pretty quickly. Beyond just sharing of files in a common Volume, there’s automated configuration, coordination, and management of service. So enter Docker orchestration tools that can help you to manage and run multiple Docker containers in a single host or a cluster of thousand nodes. Fig was an open source Docker orchestration tool developed by Orchard before it got acquired by Docker. The tool has been refined and released as Compose.
- #33: Decompose software down into multiple component services Message-based communication Decentralized data management – service manages its unique database Smart end points and dumb pipes
- #34: Datasets are often joined. For example, a user rates a movie, a movie is rated by a user, a user follows another user. The data relationships transcend the physical database. In a microservice environment, one of the most common way to resolve this issue is by having an service A to call another service B.
- #37: Running multiple containers in a single host is hard, try doing that in a cluster
- #39: Running multiple containers in a single host is hard, try doing that in a cluster
- #40: Running multiple containers in a single host is hard, try doing that in a cluster
- #41: Running multiple containers in a single host is hard, try doing that in a cluster
- #42: Running multiple containers in a single host is hard, try doing that in a cluster
- #43: Running multiple containers in a single host is hard, try doing that in a cluster
- #44: Remember the statement you heard at the beginning of the presentation? You build it; you run it