![What is a Dockerfile?
• Instructions for how to build a
Docker image
FROM anonmily/node:latest
MAINTAINER Michelle Liu
<michelle@michelleliu.io>
COPY src/node_modules /src/node_modules
COPY certs /src/certs
EXPOSE 443
WORKDIR /src
ENV PATH /src/bin:$PATH
COPY src/bin /src/bin
COPY src/app /src/app
COPY src/server.js src/app.js
src/package.json Makefile /src/
CMD ["startserver"]](https://image.slidesharecdn.com/upandrunningwithdocker-160330054116/85/Up-and-running-with-docker-42-320.jpg)
![Dockerizing a Node application
FROM anonmily/node:latest
MAINTAINER Michelle Liu
<michelle@michelleliu.io>
COPY src/node_modules /src/node_modules
COPY certs /src/certs
EXPOSE 443
WORKDIR /src
ENV PATH /src/bin:$PATH
COPY src/bin /src/bin
COPY src/app /src/app
COPY src/server.js src/app.js
src/package.json Makefile /src/
CMD ["startserver"]
/Src
app/
app.js
bin/
startserver
certs
gulpfile.js
node_modules
server.js
Makefile
Bin/
Certs/
Src/
app.js
bin/
startserver
gulpfile.js
node_modules
server.js
Server.js
Production.env
Dockerfile
Makefile
Original Folder Docker Container](https://image.slidesharecdn.com/upandrunningwithdocker-160330054116/85/Up-and-running-with-docker-44-320.jpg)
![Utilizing the Layer Cache
FROM anonmily/node:latest
MAINTAINER Michelle Liu <michelle@michelleliu.io>
COPY src/node_modules /src/node_modules
COPY certs /src/certs
EXPOSE 443
WORKDIR /src
ENV PATH /src/bin:$PATH
COPY src/bin /src/bin
COPY src/app /src/app
COPY src/server.js src/app.js src/package.json
Makefile /src/
CMD ["startserver"]
Least changed
files on top
More
frequently
changed files
on bottom](https://image.slidesharecdn.com/upandrunningwithdocker-160330054116/85/Up-and-running-with-docker-45-320.jpg)
Up and running with docker
- 1. Up and Running With Docker Presented by Michelle Liu https://github.com/anonmily/docker-up-and-running
- 2. Outline 1. What is Docker? 2. Applications of Docker 3. Terminology: How Docker Works 4. Tools 5. Installation 6. Images 7. Containers 8. Docker Registry 9. Docker Workflow 10. Docker Remote API 11. QA
- 3. The Deployment Dilemma • Inter-dependent dependencies • Inconsistent environments • Development != Production • “Works on my machine…”
- 5. Lots of dependencies/interactions between services and applications
- 6. Different approaches and tools • Virtualization • Configuration Management • Containers
- 8. Containerization = Separation of Concerns
- 9. Configuration Management Remember the exact steps needed for setup and do it all over again for all of your servers (a recipe) Docker/Containers Set up a container/image just once with all the necessary configuration, then deploy the same image to all of your servers (a golden image) What’s the difference?
- 10. Terminology: Images and Containers Image: A master template for creating Docker containers, analogous to virtual machine instances (a “golden image”) Container: An instance of an image; multiple containers can be created from a single image. A container contains isolated processes and filesystems acting in a similar fashion as virtual machines; however, a container only includes the filesystem on top of a shared kernel.
- 11. Virtual Machines Containers What’s the difference? Virtual Machines vs Containers
- 12. Virtual Machines • Kernel not shared between virtual machines • Isolated operating systems • Long-lasting use • Slower to get running • Many startup processes • A single virtual machine image can be used for multiple virtual machine clones Containers • Kernel of linux host shared between all containers • Isolated processes/filesystems • Ephemeral/long-lasting usage • Fast to get running • One startup process • A single Docker image can be used for multiple container instances What’s the difference? Virtual Machines vs Containers
- 13. What is Docker used for? • Ephemeral (temporary) isolated processes (e.g. Codepen, Codeship) • Short running tasks, maintenance scripts, or worker processes that receive then process a workload • Running and deploying stateless applications • Web frontends and backend APIs • Running isolated environments with imposed CPU/memory limits • …and more!
- 14. This means that containers are • More lightweight • Can be started, stopped, and restarted more quickly • Easier to migrate • Easier to communicate between containers What’s the difference? Virtual Machines vs Containers
- 15. Docker Server vs Docker Client Docker server/daemon: The docker server/daemon runs containers within as processes, acting as a virtual bridge to the host operating system (containers are isolated) Docker client: The command line interface (CLI) that is able to connect to the Docker server (specified by the DOCKER_HOST environmental variable) and tell it what to do. This can run on your local machine or on the same host as the Docker server.
- 16. Docker Server vs CLI
- 17. Docker Server vs CLI
- 18. Docker Server vs CLI
- 19. Docker Server vs CLI
- 20. Docker Server vs CLI
- 22. Installation - Linux curl -fsSL https://get.docker.com/ | sh service docker start Will run a setup script for installing docker Easy setup
- 23. Installation - Linux apt-get update apt-get purge lxc-docker* apt-get purge docker.io* apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D echo "deb https://apt.dockerproject.org/repo debian-jessie main" > /etc/apt/sources.list.d/docker.list apt-get -y install apt-transport-https apt-get -y update apt-get -y install docker-engine service docker start Debian/Ubuntu curl https://raw.githubusercontent.com/anonmily/scripts/master/docker-setup-debian | bash Or, just
- 24. Installation - Linux yum install docker service docker start Fedora curl https://raw.githubusercontent.com/anonmily/scripts/master/docker-setup-yum | bash Or, just
- 25. Installation – Non-Linux • Download and install the Docker Toolbox https://www.docker.com/docker- toolbox • Open the Docker Quickstart Terminal
- 27. Docker Server/CLI docker-machine create –driver virtualbox host1 docker-machine create –driver virtualbox host2 docker-machine create –driver virtualbox host3 Create a new docker host docker-machine ls List docker hosts
- 28. Docker Server/CLI docker-machine stop host1 Stop docker host docker-machine start host1 Start docker host docker-machine restart host1 Restart docker host
- 29. Docker Server/CLI docker-machine ip host1 Get IP address of host docker-machine env host1 Get environmental variables of the host
- 30. Docker Server/CLI eval $(docker-machine-env host1) Set environmental variables of CLI to communicate with a host ** If you get a “Cannot connect to the Docker daemon. Is the docker daemon running on this host?” error when attempting to use the Docker CLI, make sure the environmental variables are set for your Docker host
- 31. Docker Images • Docker images are a saved state of the container. They’re the “golden image” for your containers, and multiple containers based off the same mage can be run at the same time (executing different commands etc in the same environment if necessary) • Image ID = hashed representation of the image, a unique identifier • A Dockerfile is a file that describes all the steps needed to build a Docker image
- 32. Docker Images • Images can be tagged with a name and a version label (e.g. nginx:latest, ubuntu:14:04) • Images are stored in and can be retrieve from Docker Repositories • Docker Hub: Public repository with common base images • Private Registry: Deploy your own Docker registry
- 33. Storing Docker Images • Docker registry: A server that hosts your Docker images; it acts in a fashion analogous to repositories in that you can push and pull images from the registry. You can use a public registry like Docker hub, or you can setup your own for private images. • Docker Hub: A public Docker registry that is the default for pulling images. It provides many common base images such as Debian, Ubuntu, Fedora, etc.
- 34. Docker Hub
- 35. Deploy your own registry server
- 37. Docker Images docker pull nginx:latest Pull/get an image (from Docker Hub) # login to DockerHub docker login # private registry docker login https://myownregistry.com:5000 Login to a registry • Docker will save your login credentials in ~/.docker/config.json docker images See your downloaded/available images
- 38. Docker Images docker build –t webapp1:latest . Build a new image tagged “webapp1:latest” from a Dockerfile docker run --name="myapp" -p 80:80 -d nginx:latest nginx -g "daemon off;" Run a container from an image • --name=“myapp” Run a new container called “myapp” • -p 80:80 Expose port 80 of the host and map it to port 80 of the container • -d Run daemonized • nginx:latest Base image • nginx –g “daemon off;” Command to start the container with
- 39. Docker Images docker exec –it nodeapp bash Execute a command into a container docker ps # running containers docker ps –a # all containers List containers docker stop nodeapp Stop container docker rm nodeapp Remove container
- 40. Docker Images docker save myimage:latest > myimage.tar Save an image to a tarball docker import myimage.tar Import an image from a tarball docker commit –m “newconfig” mycontainer myimage:latest Commit/save the current state of a container to the image
- 41. Docker Images docker rmi myimage:latest Remove an image docker rmi $(docker images –q –f “dangling=true”) Delete all untagged images docker rmi $(docker images –q -) Delete all images on Docker host
- 42. What is a Dockerfile? • Instructions for how to build a Docker image FROM anonmily/node:latest MAINTAINER Michelle Liu <[email protected]> COPY src/node_modules /src/node_modules COPY certs /src/certs EXPOSE 443 WORKDIR /src ENV PATH /src/bin:$PATH COPY src/bin /src/bin COPY src/app /src/app COPY src/server.js src/app.js src/package.json Makefile /src/ CMD ["startserver"]
- 43. Anatomy of a Dockerfile • FROM what base image to use for the new image • MAINTAINER who maintains the image • COPY source destination copy files from the source location to destination • ENV set environmental variables • WORKDIR set working directory of the container • CMD run command • EXPOSE indicates what ports should be available for exposure
- 44. Dockerizing a Node application FROM anonmily/node:latest MAINTAINER Michelle Liu <[email protected]> COPY src/node_modules /src/node_modules COPY certs /src/certs EXPOSE 443 WORKDIR /src ENV PATH /src/bin:$PATH COPY src/bin /src/bin COPY src/app /src/app COPY src/server.js src/app.js src/package.json Makefile /src/ CMD ["startserver"] /Src app/ app.js bin/ startserver certs gulpfile.js node_modules server.js Makefile Bin/ Certs/ Src/ app.js bin/ startserver gulpfile.js node_modules server.js Server.js Production.env Dockerfile Makefile Original Folder Docker Container
- 45. Utilizing the Layer Cache FROM anonmily/node:latest MAINTAINER Michelle Liu <[email protected]> COPY src/node_modules /src/node_modules COPY certs /src/certs EXPOSE 443 WORKDIR /src ENV PATH /src/bin:$PATH COPY src/bin /src/bin COPY src/app /src/app COPY src/server.js src/app.js src/package.json Makefile /src/ CMD ["startserver"] Least changed files on top More frequently changed files on bottom
- 46. Building the image # ./bin/buildapi docker build -t myregistry.com/nodeapi:latest . # ./bin/pushapi docker push myregistry.com/nodeapi:latest
- 47. Updating to a newer image # ./bin/updatecontainer docker pull myregistry.com/nodeapi:latest docker kill nodeapicontainer; docker rm nodeapicontainer; docker run --name nodeapi01 -p 443:443 -dit --env-file /home/production.env myregistry.com/nodeapi:latest startserver
- 48. An easy way to deploy 1. Push the new image up onto the Docker registry (e.g. 1.0.0) 2. From the servers, pull down the new image 3. Kill the currently running container based off the old outdated image 4. Run a new container based off the new image
- 49. Updating to a newer image #!/bin/bash docker build -t myregistry.com/nodeapi:latest . docker push myregistry.com/nodeapi:latest ssh -i ~/.ssh/mysshkey [email protected] 'bash' < bin/updatecontainer ssh -i ~/.ssh/mysshkey [email protected] 'bash' < bin/updatecontainer ssh -i ~/.ssh/mysshkey [email protected] 'bash' < bin/updatecontainer
- 50. Startserver #!/bin/bash pm2 dump pm2 start /src/server.js -i 0 --name nodeapi --no-daemon & If you want to start your container up with more than one command, use a bash script
- 51. Docker remote API An API for the Docker daemon/server that allows you to make requests to/query the server for creating/editing or for information on containers/images.
- 52. Docker remote API By default, the Docker daemon will run on the unix port at /var/run/docker.sock. To get started with the Docker remote API, make sure that you have a cURL version greater than 7.40 so that the –unix-socket option is available. Then, we can use curl to interact with the remote API by: curl --unix-socket /var/run/docker.sock http://containers/json
- 53. Docker remote API It’s also possible to bind the Docker daemon to a TCP port at startup by: docker daemon –H tcp://0.0.0.0:2375 –H /var/run/docker.sock It will then be possible to access the remote API on the host publicly (though it is a security issue). curl http://localhost:2375/containers/json
- 54. More resources • http://view.dckr.info/DockerIntro.pdf • http://view.dckr.info/DockerAdvanced.pdf • https://docs.docker.com/engine/articles/dockerfile_best-practices/ • http://blog.thoward37.me/articles/where-are-docker-images-stored/ • http://blog.trifork.com/2013/12/24/docker-from-a-distance-the-remote-api/