Continuous Delivery with Containers: The Good, the Bad, and the Ugly
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The document discusses the role of containers in continuous delivery (CD), emphasizing that container images should serve as the single source of truth within build pipelines while adding necessary metadata is crucial. It highlights the importance of building, testing, and validating containers to meet system quality attributes, as well as navigating challenges posed by microservices. Additionally, the presentation underlines that while containers have significant advantages, they do not eliminate the need for robust architectural practices.
Continuous Delivery with Containers: The Good, the Bad, and the Ugly
- 1. Continuous Delivery with Containers: The Good, the Bad, and the Ugly Daniel Bryant @danielbryantuk
- 2. Containers: Expectations versus reality 13/07/2018 @danielbryantuk “DevOps”
- 3. Setting the scene… • Continuous delivery is a large topic • No business focus today (value stream etc) • PaaS and Serverless are super interesting… • But I’m assuming you’re all-in on containers • Focusing today on the process and tooling • No live coding today • Mini-book contains more details (thanks nginx!) 13/07/2018 @danielbryantuk bit.ly/2jWDSF7
- 4. TL;DR – Containers and CD • Container image becomes the build pipeline ‘single binary’ • Adding metadata to containers images is vital, but challenging • Must validate container constraints on system quality attributes (NFRs) 13/07/2018 @danielbryantuk
- 5. @danielbryantuk • Tech Consultant, Product Architect at Datawire, InfoQ News Manager • Academic, software developer, DBA, ops, CTO, conference vagabond • Continuous Delivery (CI/CD) advocate • Leading change through technology and teams 13/07/2018 @danielbryantuk
- 6. Continuous Delivery 101 13/07/2018 @danielbryantuk
- 7. Continuous Delivery • Produce valuable and robust software in short cycles • Optimising for feedback and learning • Not (necessarily) Continuous Deployment 13/07/2018 @danielbryantuk
- 8. Velocity (with stability) is key to business success “Continuous delivery is achieved when stability and speed can satisfy business demand. Discontinuous delivery occurs when stability and speed are insufficient.” - Steve Smith (@SteveSmithCD) 13/07/2018 @danielbryantuk
- 9. Creation of a build pipeline is mandatory for continuous delivery 13/07/2018 @danielbryantuk
- 10. 13/07/2018 @danielbryantuk Feedback: - Was our initial hypothesis proven? - How can we improve business, architecture and ops?
- 11. The impact of containers on CD 13/07/2018 @danielbryantuk
- 12. Container technology (and CD) • OS-level virtualisation • cgroups, namespaces, rootfs • Package and execute software • Container image == ‘single binary’ 13/07/2018 @danielbryantuk
- 15. Microservices multiply the challenges 13/07/2018 @danielbryantuk https://www.youtube.com/watch?v=b9Fu1So0bXA
- 16. Creating a pipeline for containers 13/07/2018 @danielbryantuk
- 18. Make your dev environment like production • Develop locally or copy/code in container • Must build/test containers locally • Perform (at least) happy path tests • Use identical base images from production • With same configuration 13/07/2018 @danielbryantuk
- 19. Working remotely, locally… 13/07/2018 @danielbryantuk https://opencredo.com/working-locally-with-microservices/ https://www.telepresence.io/
- 20. Lesson learned: Dockerfile content is super important • OS choice • Configuration • Build artifacts • Exposing ports • Java • JDK vs JRE and Oracle vs OpenJDK? • Golang • Statically compiled binary in scratch? • Python • Virtualenv? 13/07/2018 @danielbryantuk
- 21. Please talk to the sysadmin people: Their operational knowledge is invaluable 13/07/2018 @danielbryantuk
- 22. Different test and prod containers? • Create “test” version of container • Full OS (e.g. Ubuntu) • Test tools and data • Easy to see app/configuration drift • Use test sidecar containers instead • ONTEST proposal by Alexi Ledenev 13/07/2018 @danielbryantuk http://blog.terranillius.com/post/docker_testing/
- 23. Docker multi-stage builds 13/07/2018 @danielbryantuk http://blog.alexellis.io/mutli-stage-docker-builds/ https://github.com/moby/moby/pull/31257 https://github.com/moby/moby/pull/32063
- 25. Building images with Jenkins • My report covers this • Build as usual… • Build Docker Image • Cloudbees Docker Build and Publish Plugin • Push image to registry 13/07/2018 @danielbryantuk
- 26. Lesson learned: Metadata is valuable • Application metadata • Version / GIT SHA • Build metadata • Build date • Image name • Vendor • Quality metadata • QA control, signed binaries, ephemeral support • Security profiles (AppArmor), Security audited etc 13/07/2018 @danielbryantuk
- 27. Metadata – Beware of “latest” Docker Tag • Beware of the ‘latest’ Docker tag • “Latest” simply means • the last build/tag that ran without a specific tag/version specified • Ignore “latest” tag • Version your tags, every time • danielbryantuk/test:2.4.1 13/07/2018 @danielbryantuk
- 28. Metadata - Adding Labels at build time • Docker Labels • Add key/value data to image 13/07/2018 @danielbryantuk
- 29. Metadata - Adding Labels at build time • Microscaling Systems’ Makefile • Labelling automated builds on DockerHub (h/t Ross Fairbanks) • Create file ‘/hooks/build’ • label-schema.org • microbadger.com 13/07/2018 @danielbryantuk
- 30. Metadata - Adding Labels at runtime 13/07/2018 @danielbryantuk $ docker run -d --label uk.co.danielbryant.lbname=frontdoor nginx • Can ’docker commit’, but creates new image • Not possible to update running container • Docker Proposal: Update labels #21721
- 31. External registry with metadata support 13/07/2018 @danielbryantuk
- 32. Grafeas + Kritis 13/07/2018 @danielbryantuk
- 35. Running tests with containers 13/07/2018 @danielbryantuk
- 36. Testing NFRs in the build pipeline • Architecture • Performance and Load testing • Gatling / jmeter / Flood.io • Security testing • Findsecbugs / OWASP Dependency check • Bdd-security (OWASP ZAP) / Arachni • Gauntlt / Serverspec • Docker Bench for Security / CoreOS Clair 13/07/2018 @danielbryantuk
- 37. Security Visibility: Basic (Java) Code Scanning 13/07/2018 @danielbryantuk
- 39. Static Image Scanning 13/07/2018 @danielbryantuk github.com/arminc/clair-scanner
- 40. Delaying NFRs to the ‘Last Responsible Moment’ Newsflash! Sometimes the last responsible moment is up-front Modern platforms/architectures don’t necessarily make this easier 13/07/2018 @danielbryantuk
- 41. Important things not covered 13/07/2018 @danielbryantuk
- 42. Mechanical sympathy: Docker and Java • Watch for JVM cgroup/taskset awareness (with JDK <= 8) • getAvailableProcessors() may incorrectly report the number of cpus in Docker (JDK-8140793) • Runtime.availableProcessors() ignores Linux taskset command (JDK-6515172) • Default fork/join thread pool sizes (and others) is based from host CPU count • Set container memory appropriately • JVM requirements = Heap size (Xmx) + Metaspace + JVM overhead • Account for native thread requirements e.g. thread stack size (Xss) • Entropy • Host entropy can soon be exhausted by crypto operations and /dev/random blocks • -Djava.security.egd=file:/dev/./urandom (notes on this) 13/07/2018 @danielbryantuk 42
- 44. Observability is core to continuous delivery 13/07/2018 @danielbryantuk www.infoq.com/articles/monitoring-containers-at-scale
- 45. Containers are not a silver bullet 13/07/2018 @danielbryantuk
- 46. Moving to containers: Going all-in? 13/07/2018 @danielbryantuk OR
- 47. Using containers does not get rid of the need for good architectural practices 13/07/2018 @danielbryantuk
- 50. In summary • Continuous delivery is vitally important with modern architecture/tech • Container images must be the (single) source of truth within pipeline • And metadata added as appropriate… • Mechanical sympathy is important (assert properties in the pipeline) • Not all developers are operationally aware • The tooling is now becoming stable/mature • We need to re-apply existing CD practices with new technologies/tooling 13/07/2018 @danielbryantuk
- 51. Thanks for listening… Twitter: @danielbryantuk Email: daniel.bryant@tai-dev.co.uk Writing: https://www.infoq.com/profile/Daniel-Bryant Talks: https://www.youtube.com/playlist?list=PLoVYf_0qOYNeBmrpjuBOOAqJnQb3QAEtM 13/07/2018 @danielbryantuk bit.ly/2jWDSF7 Coming soon!
- 53. Bonus slides (for extra context) 13/07/2018 @danielbryantuk
- 54. Containerise an existing (monolithic) app? • For • We know the monolith well • Allows homogenization of the pipeline and deployment platform • Can be a demonstrable win for tech and the business • Against • Can be difficult (100+ line scripts) • Often not designed for operation within containers, nor cloud native • Putting lipstick on a pig? 13/07/2018 @danielbryantuk
- 55. Key lessons learned • Conduct an architectural review • Architecture for Developers, by Simon Brown • Architecture Interview, by Susan Fowler • Look for data ingress/egress • File system access • Support resource constraints/transience • Optimise for quick startup and shutdown • Evaluate approach to concurrency • Store configuration (secrets) remotely 13/07/2018 @danielbryantuk
- 56. New design patterns 13/07/2018 @danielbryantuk bit.ly/2efe0TP
- 57. Microservices… Containers and microservices are complementary Testing and deployment change 13/07/2018 @danielbryantuk https://specto.io/blog/recipe-for-designing-building-testing-microservices.html
- 61. Quick Aside: Running *entire* system locally 13/07/2018 @danielbryantuk https://news.ycombinator.com/item?id=13960107 https://opencredo.com/working-locally-with-microservices/ https://www.datawire.io/telepresence/ | https://hoverfly.io/