Docker, Ceci N'Est Pas Une Introduction (APIHour #12)

Docker, l'une des technologies les plus en vogue ces derniers temps, permet de créer des conteneurs logiciels. Retour sur mon utilisation pour le développement mais également pour la production, avec en ligne de mire : une architecture micro-services, quelques principes 12 Factors et un déploiement en (presque) zéro-downtime.

Sources: https://github.com/willdurand-slides/docker-clermontech

Transcript

1. (Ceci N'Est Pas Une Introduction) William Durand ‑ December 16th, 2014
2. Docker In A Nutshell
3. Containers A container is an operating‑system level virtualization method that provides a completely isolated environment, simulating a closed system running on a single host. chroot, OpenVZ, Jail, LXC, etc.
4. Containers vs VMs
5. Docker Developed by Docker.inc (formerly DotCloud) Open platform for developing, shipping, and running applications Use as execution driver libcontainer
6. Docker's Architecture Host Container 1 Container 2 Container 3 Container ... Docker Client docker pull docker run docker ... Docker Index Docker Daemon
7. The Plan Simple solution to deploy my application Idempotent and reliable process No need for rollbacks Targetting zero downtime Single host
8. How?
9. Methodology
10. Twelve Factors One codebase tracked in revision control, many deploys Store config in the environment Keep development, staging, and production as similar as possible by The Twelve‑Factor App @aymericbrisse
11. Infrastructure
12. Services Reverse proxy: (+ ) Backend: + + application Sessions are stored into Database (at some point...) Hipache Redis Nginx HHVM memcached
13. Overall Architecture
14. Application's fig.yml web: build: . # No support for `env-file` yet... # See: https://github.com/docker/fig/pull/665 environment: - SYMFONY_ENV=dev - SYMFONY_DEBUG=1 - SYMFONY__MEMCACHED_HOST=memcached - SYMFONY__MEMCACHED_PORT=11211 - SYMFONY__SESSION_MEMCACHED_PREFIX=session - SYMFONY__SESSION_MEMCACHED_EXPIRE=604800 links: - memcached - database
15. Application's Dockerfile FROM debian:wheezy MAINTAINER William Durand <william.durand1@gmail.com> ENV DEBIAN_FRONTEND noninteractive # Let APT know about HHVM repo... RUN apt-get update -y RUN apt-get install -y nginx hhvm supervisor # Configure Nginx, HHVM, Supervisor here... ADD . /app WORKDIR /app EXPOSE 80 CMD [ "/usr/bin/supervisord" ]
16. DNS example.org w www.example.org Configured at the DNS level. Faster than making this redirection using the load balancer.
17. SSL Hipache listens on ports 80 and 443. Patched version of Hipache to redirect HTTP traffic to HTTPS. Sort of SSL offloading. ® willdurand/docker‑hipache
18. Deploy
19. 1. Build Artifact git archive --format tar --prefix myapp/ <SHA> | (cd /tmp && tar xf -) Protip: use a Docker container to run build tools: cd /tmp/myapp docker run --rm -v `pwd`:/srv buildtools composer install docker run --rm -v `pwd`:/srv buildtools bundle install docker run --rm -v `pwd`:/srv buildtools bower install rm <USELESS/TEMP FILES>
20. 2. Build Container (From Artifact) docker build -t myapp:latest .
21. 3. Push It docker push q Or whatever that makes the image available on the production server.
22. 4. Retrieve Running Containers RUNNING_CIDS=$(docker ps | grep web | cut -d ' ' -f 1)
23. 5. Run The New Container fig run -d --no-deps --rm web † Booting the container may take a few seconds, wait.
24. 6. Register It As Backend IP=$(docker inspect --format='{{ .NetworkSettings.IPAddress }}' <CID>) fig run --rm rediscli rpush frontend:www.example.com "http://$IP:80" # fig.yml rediscli: image: redis entrypoint: [ redis-cli, -h, redis ] links: - redis
25. 7. Unregister Previous Backends For each container id CID in $RUNNING_CIDS, do: IP=$(docker inspect --format='{{ .NetworkSettings.IPAddress }}' <CID>) fig run --rm rediscli lrem frontend:www.example.com 0 "http://$IP:80" † New backend is up and serves requests. However, previous backends may still process requests. Wait.
26. 8. Stop Previous Containers For each container id CID in $RUNNING_CIDS, do: docker stop <CID>
27. 9. Tag A Release (And Profit!)
28. Testing
29. Like , but better! Apache Bench ® tarekziade/boom
30. 1. Run boom boom https://www.example.org/ -n 2000 -c 50 Server Software: nginx/1.2.1 Running GET https://www.example.org/ Running 2000 times per 50 workers. [================================================================>.] 99% Done -------- Results -------- Successful calls 2000 Total time 137.1827 s Average 6.7114 s Fastest 2.3701 s Slowest 9.4738 s Amplitude 7.1037 s -------- Status codes -------- Code 200 2000 times.
31. 2. Deploy fab deploy --hide=running,stdout,stderr ---> Deploying branch "awesome-feature" ---> Building artifact ---> Artifact id is: "build-8fe47fc" ---> Pushing artifact to the server ---> Building container ---> Finding running containers ---> Starting new container ---> Waiting while container is booting ---> Registering new backend to Hipache ---> Unregistering the previous backends from Hipache ---> Waiting before stopping the previous backends Done. q I use . Fabric
32. 3. Monitor Elasticsearch, Logstash, Kibana + Logstash Forwarder (lumberjack) ® willdurand/docker‑elk ® willdurand/docker‑logstash‑forwarder
34. Thank You. Questions? ¾ ® ¬ williamdurand.fr github.com/willdurand twitter.com/couac
35. Bonus
36. Fig & Environments Keep development, staging, and production as similar as possible X. Dev/prod parity — 12 Factors # fig.yml.dist web: # In PRODUCTION, the line below MUST be COMMENTED: build: . # In PRODUCTION, the line below must be UNCOMMENTED: # image: myapp # ...
37. Data Only Containers Data, logs, etc. MUST live in data only containers: # fig.yml redis: image: redis volumes_from: - dataredis dataredis: image: busybox volumes: - /data Wanna backup? ė docker run --rm \ --volumes-from dataredis \ -v $(pwd):/backup \ busybox \ tar cvf /backup/dataredis.tgz /data