#serverless - 🛳 mettez-le en œuvre dans votre entreprise et arrivez à bon port

Tout comme le Cloud IaaS avant lui, le serverless promet de faciliter le succès de vos projets en accélérant le Time to Market et en fluidifiant les relations entre Devs et Ops.

Mais sa mise en œuvre au sein d’une entreprise reste complexe et coûteuse.

Après 2 ans à mettre en place des plateformes managées de ce type, nous partagons nos expériences de ce qu’il faut faire pour mettre en œuvre du serverless en entreprise, en évitant les douleurs et en limitant les contraintes au maximum.

Tout d’abord l’architecture technique, avec 2 implémentations très différentes : Kubernetes et Helm d’un côté, Clever Cloud on-premise de l’autre.

Ensuite, la mise en place et l’utilisation d’OpenFaaS. Comment tester et versionner du Function as a Service. Mais aussi les problématiques de blue/green deployment, de rolling update, d’A/B testing. Comment diagnostiquer rapidement les dépendances et les communications entre services.

Enfin, en abordant les sujets chers à la production :
* vulnerability management et patch management,
* hétérogénéïté du parc,
* monitoring et alerting,
* gestion des stacks obsolètes, etc.

Transcript

1. #breizhcamp 2+ years of feedback #serverless Adrien Blind, Laurent Doguin, Laurent Grangeau, Ludovic Piot
2. We gonna talk about… • Serverless, big deal… • 3 different ways to talk about serverless − Oxalide feedback : almost-CaaS avec Kubernetes − Clever Cloud feedback : You write code, we run IT − FaaS, a new kid in the block
3. starring… Adrien Blind @AdrienBlind DevOps Evangelist Docker Captain Ludovic Piot @lpiot DevOps @ Cloud leader Laurent Doguin @ldoguin Developer Relations VP Laurent Grangeau @laurentgrangeau Cloud Solution Architect
4. Introduction to serverless Introduction Serverless, a big deal?
5. What does the business wants? Deliver rapidly and flowly valuable apps for the business
6. What does the business wants? Cloud Agile DevOps Microservice architecture Deliver rapidly and flowly valuable apps for the business
7. What do you really want? On demand Pay as you go Elastic Cloud Agile DevOps Microservice architecture Deliver rapidly and flowly valuable apps for the business
8. A new kid on the block?
9. A new “cloudy” kid on the block!
10. “Serverless computing is a cloud computing execution model in which the cloud provider dynamically manages the allocation of machine resources” - Wikipedia “Serverless computing refers to the concept of building and running applications that do not require server management. It describes a finer-grained deployment model where applications, bundled as one or more functions, are uploaded to a platform and then executed, scaled, and billed in response to the exact demand needed at the moment.” - CNCF foundation whitepaper on Serverless “Serverless architectures refer to applications that significantly depend on third-party services (knows as Backend as a Service or "BaaS") or on custom code that's run in ephemeral containers (Function as a Service or "FaaS") [...]. such architectures remove the need for the traditional 'always on' server system sitting behind an application.” - Mike Roberts, martinfowler.com (2016) “If your PaaS can efficiently start instances in 20ms that run for half a second, then call it serverless.” - Adrian Cockroft (2016) A single definition for Serverless?
11. ❏ Dev/App perspective Arch. design & granularity? Ephemeral apps? PaaS pattern? Mostly all of them! ❏ Ops/platform perspective: infrastructure abstraction Elastic → autoscaling On-demand → boot in 20 ms Pay-as-you-go → Scale to zero What are we talking about?
12. ❏ BaaS, aka Backend-as-a-Service ❏ FaaS, aka Functions-as-a-Service 2 major serverless tendencies
13. Cloud: Container as a Service ❏ Portability: containers isolate app/runtimes from subsequent OS ❏ Orchestrators enables to consider a pool of OS as a global resource ❏ Auto-scalability mostly based on infrastructure metrics (CPU) ❏ Pricing model mostly related to subsequent infrastructure used (cluster nodes) ❏ Containers commonly associated to finer app granularity
14. Cloud: Platform as a Service ❏ Application PaaS (aPaaS) pioneer: Google App engine ❏ xPaaS = managed services (DBaaS, object storage, etc.) ❏ Complete abstraction from infrastructure ❏ Pricing model not related to infrastructure ❏ Autoscaling & resilient by design
15. ❏Not a cloud service offer, it’s an architecture concept ❏Build apps directly leveraging on PaaS services ❏ Security paradigms shifts From perimetric to embedded Auth/Authz/Cipher everything Backend-as-a-Service architecture Authentication Object Storage Databases (ex. DynamoDB, CosmosDB, etc.)
16. ❏ Ephemeral: platform waits requests FaaS platform FaaS compute capacity abstracted from dev perspective Cloud: FaaS Client Gateway Event queues
17. ❏ Ephemeral: platform waits requests and instantiate function on demand, which “lives” the time to deliver the result: not always-on! FaaS platform FaaS compute capacity abstracted from dev perspective Cloud: FaaS Instanciated function (your code) Gateway Client Event queues
18. ❏ Ephemeral: platform waits requests and instantiate function on demand, which “lives” the time to deliver the result: not always-on! ❏ Dynamic scalability & resilience provided by the platform: more calls, more instances ❏ Extremely fine grained pay-per-use on public cloud: per-call costs FaaS platform FaaS compute capacity abstracted from dev perspective Cloud: FaaS Instanciated function (your code) Instanciated function (your code) Instanciated function (your code) Gateway Client Event queues
19. ❏ Beware of design constraints applying to your app ❏ Service/function granularity ❏ Stateless services ❏ Small wake up time ❏ No long-running services ❏ Deal with function graph calls & orchestration ❏ Possible Vendor lock-in: check out serverless.io? ❏ Testing → you must deploy on the platform everytime ❏ Adapt DevOps practices: monitoring, deployment, versioning... FaaS constraints
20. All major cloud vendors have products Alternatively you can deploy your own FaaS framework You may leverage on existing CaaS and put value on top of it • Container encapsulation of the function • Kubernetes orchestration Cloud: FaaS
21. Serverless key aspects -dev/app perspective ❏ Serverless is an architecture trend, not just a new cloud service offer (aka FaaS) ❏ A serverless app is a mashup of value-added, managed services: aPaaS, xPaaS, FaaS… ❏ Fits today’s architecture stakes: cloud native apps, 12 factors... Devs gain a greater productivity, refocusing on business valuable code
22. Serverless key aspects -ops/ptf perspective ❏ You no longer manage infrastructure aspects directly: auto-scalability & resilience provided by design ❏ Close to NoOps ❏ Cloud promise at its finest “resolution” On-demand, Elastic, Pay-Per-Use Ops gets more efficiency and cost-saving, offloading several concerns to platform
23. From IaaS to FaaS Focus on value & better TTM but support platform constraints More flexibility, more tuning capacity… but assume plumbing Functions ABSTRACT FOCUS INFRA Microservices Monoliths CaaS IaaS FaaS & PaaS
24. Some usecases ❏ Small microservices ❏ Stream processing ❏ IoT / Event-driven-programming ❏ Batch / Scheduled tasks ❏ May even replace some old compute grids ;)
25. Feedback #1 - almost-CaaS with Kubernetes Feedback #1 almost-CaaS based upon Kubernetes
26. Taking advantage of public cloud models On-premise Iaas Paas Caas RESPONSIBILITIES Define who’s responsible for what… overlap might happens. ▪ Cloud provider ▪ Outsourcer ▪ Client PROPERTY Cloud platforms are client’s proprerty. Governance might be delegate to outsourcer. Hypervisor VM OS Libs conf. Kernel HDW Middleware conf. Apps conf. Server Storage Network Logs / Metrology / Backups Data Runtime conf. Container conf.
27. Cross-validation to share knowledge
28. Take advantage of Docker image inheritance Dev team Ops team Container Apps Middle wares Libs OS conf. conf. conf. conf . Container Libs OS conf. conf. Image Container Middle wares conf. Container Apps conf. Image Image ☹ Not prod-ready Container Apps conf. prod-r eady Prod ready Image Prod ready
29. Serverless or not? Serverless or not? Managed infrastructure and services Usage ✅ Cost ⛅ ▪ Infrastructure is fully managed ▪ K8S primitives empower user enough to provision resources (volume claim, ingress) ▪ services are fully managed ▪ Runtimes are partially managed since they are included in application docker images Abstraction of any server notion Usage ✅ Cost ❌ ▪ On a developer perspective, YES ▪ Self-healing and auto-scaling ▪ But on a cost perspective, he still pays for servers Cost scales to 0 Cost ❌ ▪ On a developer perspective, YES Fast provisioning Usage ✅ ▪ Booting up a K8S pod depends on what the Docker image is containing. Most of the time < 10 sec.
30. Feedback #2 - Clever Cloud PaaS Feedback #2 Clever Cloud PaaS You write code - We Run IT
31. PaaS Players
32. PaaS for developers PaaS promise ▪ git push and it works! ▪ Production grade! ▪ No-OPS! ▪ Limited catalog ▪ Opinionated way of running apps ▪ No vendor lock-in DEV OPS
33. PaaS for developers PaaS promise ▪ git push and it works! ▪ Production grade! ▪ No-OPS! Using a PaaS: ▪ Choose a runtime + build tool ▪ Write your app. code ▪ Add git remote branch ▪ Push to remote ▪ You are in production! DEVELOPER ACTIVITY PLATFORM ACTIVITY
34. Shift from machine to application BASIC DEPLOYMENT UNIT from machine to application Production grade ▪ Provisioning on-demand ▪ Immutable architecture ▪ No interruption of service ▪ Security ▪ Automatic scalability ▪ Monitoring and logs ▪ No-OPS!
35. PaaS - under the hood Provisioning on-demand ▪ CLI, Web console, API ▪ Runtime and add-ons catalog ▪ Dynamically configured reverse-proxies & DNS ▪ Self-healing and autoscaling CLI WebUI API Message broker Deployment scheduler Dev hipster Reverse-proxies Hypervisors VMs Message broker VM images catalog Monitoring & logging
36. PaaS - under the hood Immutable infrastructure ▪ Preset KVM optimized and secured images ▪ maintained on our own ▪ copy-on-write -> VM boots in 7 sec ▪ Linux Exherbo distribution ▪ maintained on our own ▪ source-based ▪ upstream ▪ to be more reactive and efficient against security threats ▪ Application build on-site from source code ▪ Alerting users on old instances to make them redeploy ▪ Details here: https://www.youtube.com/watch?v=CeaoTAXkIZE CLI PaaS Ops VM images catalog Hypervisors VMs Building binaries
37. PaaS - under the hood Application deployment ▪ Application build on-site from source code ▪ Automated build ▪ introspect source code to determine build tool needed ▪ keep build cache for autoscaling purpose CLI Hypervisors VMs Building binaries Dev hipster App deployer
38. Blue/green deployment pattern Blue/green deployment ▪ No interruption of service ▪ Auto-restart when crashed ▪ Shadow upgrade ▪ Dynamic scalability
39. Will IT Scale?
40. Serverless or not? Serverless or not? Managed infrastructure and services Usage ✅ Cost ⛅ ▪ Infrastructure is fully managed ▪ User cannot claim any specific infrastructure resource BUT use available add-ons ▪ services are fully managed ▪ Runtimes are fully managed Abstraction of any server notion Usage ✅ Cost ❌ ▪ On a developer perspective, YES ▪ Self-healing and auto-scaling ▪ But on a cost perspective, he still pays for servers Cost scales to 0 Cost ⛅ ▪ Auto-scaling can get cost very low, but still not 0 yet Fast provisionning Usage ✅ ▪ Booting up an app is around 7 sec after the first build
41. Feedback #3 - FaaS Retour d’expérience #3 FaaS, the new hype
42. FaaS model
43. FaaS model
44. FaaS pattern
45. On-Premise Serverless Functions made simple for Docker and Kubernetes
46. On-Premise
47. OpenFaaS highlights ❏ Ease of use through UI portal and one-click install helm upgrade --install rivieradev openfaas/ --namespace rivieradev -f values.yaml ❏ Write functions in any language for Linux or Windows and package in Docker/OCI image format ❏ Portable - runs on existing hardware or public/private cloud - Kubernetes and Docker Swarm native ❏ CLI available with YAML format for templating and defining functions faas-cli build | push | deploy -f myfn.yml ❏ Auto-scales as demand increases
48. OpenFaaS gateway
49. OpenFaaS gateway
50. OpenFaaS gateway
51. OpenFaaS idler
52. OpenFaaS cloud
53. OpenFaaS cloud
54. OpenFaaS cloud
55. OpenFaaS cloud
56. OpenFaaS monitoring
57. OpenFaaS compared OpenFaaS Kubeless Knative Vendor Community Bitnami Google Maturity 2 years 2 years 3 months Docker YAML Stack / CRD CRD CRD Stable Lightweight Code limits 50kb / 1 mb Zero-scale
58. FaaS - the Clever Cloud way… Function deployment ▪ Functions built on-site as WebAssembly binary ▪ Each function isolated into a VM ▪ VM have no OS but a lightweight WASM “Bootloader” ▪ the Unikernel way CLI Hypervisors VMs Building WebAssembly binaries Dev hipster WASM function + bootloader”
59. Final thoughts Finally, the ending word Serverless & beyond!
60. Serverless & IoT ❏ IoT generates large loads of small & basic-to-process events, in huge quantity ❏ It calls for an event-driven programming approach ❏ … which fits well with the idea of simple, elementary functions of Serverless/FaaS computing Serverless + IoT It’s a match!
61. Serverless & edge computing ❏ Google Trends graphs for “Serverless” & “Edge computing” terms ❏ Beware, scales are not the same ;) ❏ Anyway, an interesting correlation to notice, isn’t it ?
62. WTF with Edge computing? ❏ Offload computing tasks close to the data, at the border of the network / out from the cloud ❏ Example, precompute face recognition close to a camera, to avoid uploading the whole video flow to the cloud ❏ Particularly valuable in an IoT landscape CLOUD EDGE
63. Unleash from the Cloud Major cloud vendors are building their strategy on top of the following triptic, to unleash their service from the cloud For instance: Azure IoT Edge / Sphere, AWS Greengrass... Edge Computing Serverless Architecture Internet Of Things New connectivity 5G/Sigfox/Laura... Event-driven programing
64. Questions ?
65. ROTI