D1-2 Thomas Philipona - What Devs Should Consider, When Coding Applications

The third generation of OpenShift is built around applications running in Docker containers and makes use of Kubernetes when it comes to orchestration and management. Accurately exposing the underlying Docker concepts and, hence, facilitating the composition of applications, OpenShift v3 opens up new prospects for both operations and development.

First of all, we want to discuss challenges of Docker in a production environment and brush-up how deployment and network configuration works.

Secondly, we show how OpenShift v3 integrates with Docker and how it eases much of the burden developers used to struggle with in former PaaS environments. These alleviations allow developers to turn toward higher-level tasks like deployment automation or container building.

Next, we examine different approaches to implement Continuous Delivery and showcase our CI/CD environment at Puzzle ITC with a particular focus on Jenkins, database migrations, and integration testing.

Finally, we explain what it actually means to develop cloud-ready applications. There are some rules and best practices to be followed in order for applications to leverage the PaaS layer. One of the perspectives of the presentation is to cause awareness for this ruleset and to demonstrate how to avoid the most common design pitfalls which will imply collisions with PaaS concepts. We are going to talk about persistent storage, environment configuration, logging, monitoring, and some other aspects of a Twelve-Factor app.

Transcript

1. What Devs Should Consider, When Coding Applications
2. • Introduction • Context • Challenges and Approaches
3. Thomas Philipona • CTO @ Puzzle ITC • OpenSource • Responsible for our CI/CD Processes • APPUiO – Swiss Container Platform @tphilipona phil-pona
4. www.puzzle.ch @puzzleitc | |
5. Context
6. Container Hype ©Håkan Dahlström Source: https://www.flickr.com/photos/dahlstroms/3144199355 Container Hype Docker | Rocket | Dev - driven | Ecosystem
7. Docker in Production Monitoring Log server Storage Jenkins Mail server DB Server Backup Network Lifecycle Container u. Infrastruktur
8. How it all began Multiple Workloads | OpenShift 3 | Internal use | Platform to run our Apps
9. Our Container Platform Cloudscale IaaS ✓ ISO 27001 ✓ FINMA ✓ -based ✓
10. Docker Kubernetes APPUiO is based on
11. Our Application Stack Angular 2 Client DB External Services Wildfly 10 Java EE 7 . . .
12. Challenges and Approaches
13. Dynamic Container Platform Restarts of nodes due to maintenance Container gets moved due to ressource allocation → Start up time of the Application → Robustness Reconnect of Backends → at least two instances running
14. Start Up Time of Applications 17:11:38,607 INFO [org.jboss.as] (MSC service thread 1-7) WFLYSRV0049: WildFly Full 10.0.0.Final (WildFly Core 2.0.10.Final) starting ... ... 17:13:10,297 INFO [org.jboss.as] (Controller Boot Thread) WFLYSRV0025: WildFly Full 10.0.0.Final (WildFly Core 2.0.10.Final) started in 93046ms - Started 1235 of 1510 services (409 services are lazy, passive or on-demand)
15. Scalability Stateless architecture No session pinning (Sessions in the database or at the client) No local filesystem → Easier testable . . .
16. Avoid Long Running Tasks Avoid them completely (if possible) Separate processes / applications running along the application Split them into parts, allow continuation t . . .
17. Monitoring / Application Healthchecks View into platform | fast feedback | easily integrated into infrastructure
18. Monitoring / Healthchecks Liveness check /health Process is running If not ok, process gets restarted Readiness check /health/ready Deployment ok Ready for requests Fully functional Health checks as simple JSON response on a REST endpoint
19. Cascading Checks app DB backend GET /health GET /health select 1 from ... HTTP/1.1 200 OK { "status": "UP", "db": { "status": "UP" }, "backend": { "status": "UP" } }
20. Cascading Errors app DB backend GET /health GET /health select 1 from ... HTTP/1.1 299 Warning { "status": "UP", "db": { "status": "DOWN" }, "backend": { "status": "UP" } }
21. Advantages Easily integratable into external monitoring and alarming Kubernetes / OpenShift uses those heath checks
22. Automation and CI/CD Git code Compile, Unit-tests Integration Tests, Package Deploy to Dev Acceptance Tests Deploy to UAT env Manual Tests Deploy to Prod
23. keep everything you need to build, deploy, test, & release in version control
24. Groovy Jenkins Pipeline Scripts stage 'Build' sh "${mvnHome}/bin/mvn versions:set -DnewVersion=${buildVersion}" sh "${mvnHome}/bin/mvn clean install" // prepare Dockerfile and Context sh "tar cvfz docker-context.tar.gz Dockerfile target/javaee7-wildfly-example.war" archive 'docker-context.tar.gz'
25. If It Hurts, Do It More Frequently, and Bring the Pain Forward Source: Jez Humble, David Farley, Continuous Delivery, Pearson Education, Inc. 2011
26. Automated Database Migrations DB migrationscripts are part of the deployed application and run during startup or deployment. $ php bin/console doctrine:schema:update $ rake db:migrate
27. Conclusion
28. Heterogeneous Team Devs | Ops | User Experience | Product Owner
29. The Twelve-Factor App Framework / Manifest on how to build Software-as-a-Service Apps • To max the portability and decrease vendor lockin • Deployment on cloud-platforms • Ensure continuous deployment • Scalability https:/ /12factor.net/