Zero downtime Java deployments with Docker & Kubernetes
•
20 likes•7,198 views
JavaOne 2015 presentation by Paul Bakker & Arjan Schaaf on deploying java applications without downtime using Docker and Kubernetes
Recommended
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (20)
Similar to Zero downtime Java deployments with Docker & Kubernetes
Similar to Zero downtime Java deployments with Docker & Kubernetes (20)
Recently uploaded
Recently uploaded (20)
Zero downtime Java deployments with Docker & Kubernetes
- 1. Zero downtime Java deployments with Docker & Kubernetes @pbakker @arjanschaaf
- 2. Why care about containers Don’t worry about environment setup Easy to replicate to dev/test/prod More compact than VMs
- 3. Why care about Kubernetes Docker is about containers on a single host How to deploy on a cluster? What about failover of nodes? How to network between nodes?
- 4. Automated, production ready Kubernetes cluster in steps8
- 5. Step Understanding Kubernetes 0 Terminology, and concepts to build upon
- 7. Deployment 101 Push your Docker image Create a new replication controller JSON file kubectl create -f mycontroller.json Replication Controller creates Pods
- 10. Updating my app Create a new Replication Controller JSON file kubectl create -f my-new-rc.json Scale down and delete old RC
- 11. Step Automated deployment (simplistic) 1 This kubectl stuff doesn’t really feel like automation…
- 12. The simplest Automated deployment Don’t use kubectl, use the API! Build server creates Replication Controller using REST Build server destroys old cluster using REST
- 15. What about downtime? Not quite there yet
- 16. Step Load balancing 2 Our containers are running, but how do we access them!?
- 17. Pods come and go Pods have dynamic IP addresses First try - Kubernetes Services A service is a proxy to your Pods Fixed IP P O D S E R V I C E
- 19. What about SSL offloading? … better load balancing? … redirects, rewrites, etc? … and that “fixed” IP can’t be reached!? Services - Not quite right
- 20. Services are for communication within the k8 network (inter Pod communication) Services - A Hammer and screws…
- 21. Docker container Docker container Docker container Docker container Pods Node Docker container Docker container Docker container Docker container Pods Node HAProxy HTTPS Virtual IP Virtual IP Fixed IP Custom load balancer confd etcd HTTP HTTP
- 22. Proxy Registrator Kubernetes API confd etcd Proxy Registrator Watch update backend configurations watch changes HAProxy update config file
- 23. Choosing a load balancer Vulcand uses etcd for all its config Can use Nginx / HAProxy with templating confd
- 24. So you’re telling me… —link doesn’t work!? And now you’re telling me… —I can’t see my Pods!?
- 25. Step Software Defined Network 3 Each Pod gets its own IP Access Pods from outside k8 on the flannel network
- 26. Docker container Docker container Docker container Docker container Node Docker container Docker container Docker container Docker container Pods Node HAProxy HTTPS Virtual IP Virtual IP Fixed IP Pods HTTP HTTP Kubernetes networkpublic addressable network segment
- 27. Docker container Docker container Docker container Docker container Node Docker container Docker container Docker container Docker container Pods Node HAProxy HTTPS Virtual IP Virtual IP Fixed IP Pods HTTP HTTP Flannel networkpublic addressable network segment
- 28. Flannel: easy to setup & fast (on CoreOS) Weave: userspace implementation is slow, loads of features Project Calico: promising integration with Kubernetes Docker libnetwork: batteries included but swappable SDN - loads of options
- 29. Step Blue / Green deployment 4 Auto deploy is great, but downtime not so much
- 30. Step 4 - Blue / Green Scale up new cluster Wait until healthy Switch backend in Load Balancer Dispose old cluster
- 31. How do we know a Pod is healthy? Its RUNNING status is not sufficient… Is the app fully started?
- 32. Introduce App level health checks Docker container Docker container Docker container Docker container Node Docker container Docker container Docker container Docker container Pods Node Deployer GET /health GET /health Pods Deploy Server
- 33. Running a Deployer Blue/Green deployment requires lots of coordination Our build server can’t access the Pods … how do we health check?
- 34. Kubernets API etcd Deployer Build Server Start deployment Kubernets API Kubernets API Kubernets APIPods GET /health Create RC Switch Load Balancer Backend
- 35. Kubernets API HAProxy etcd Deployer Build Server Start deployment Kubernets API Kubernets API Kubernets APIPods GET /health Create RC Proxy Registrator Watch Create backends Read config confd Watch Switch Load Balancer Backend
- 36. Deployment descriptor { "useHealthCheck": true, "newVersion": "${bamboo.deploy.version}", "appName": "todo", "replicas": 2, "frontend": "rti-todo.amdatu.com", “podspec": { …. } }
- 37. "podspec": { "containers": [{ "image": “amdatu/mycontainer", "name": "todo", "ports": [{ "containerPort": 8080 }], "env": [ { "name": "version", "value": "${bamboo.deploy.version}" } ]}] }
- 41. Canary deployments Different strategy for the Deployer Add Replication Controller But don’t change the running cluster
- 42. K8 NodeK8 NodeK8 NodeK8 NodeProd pod Canary Main Replication Controller K8 NodeK8 NodeK8 NodeK8 NodeCanary pod Canary Replication Controller HAProxy
- 43. Step Persistent data 6 How to deploy Mongo/MySQL/ElasticSearch in Kubernetes?
- 44. You don’t
- 45. Kubernetes is great for… Stateless containers Running lots of containers together Moving containers around
- 46. Datastores scaling mechanics Reactive scaling makes less sense Cluster should be tuned Scaling is expensive
- 47. Infra server(s) K8 Master K8 NodeK8 NodeK8 NodeK8 NodeK8 NodeHAProxy Deployer Mongo Cluster ElasticSearch Cluster … Cluster Cluster topology
- 49. Logging Centralised application logging is key in a dynamic environment Assume you can’t access a pod ElasticSearch / LogStash / Kibana or Graylog are very useful for this
- 53. Step Configuration 8 Passing config to containers
- 54. Use environment variables dbName=todo-app host=${mongo} myconfig.cfg "podspec": { "env": [ { "name": "mongo", "value": "10.100.2.4" }, Deployment descriptor Approach 1
- 56. What to learn from all this? Docker and Kubernetes are awesome They are building blocks, not solutions Use the API!
- 57. And if you don’t want to do all this yourself…. Fully managed Kubernetes based clusters Logging and Monitoring Automated deployments
- 58. Thank you! Blog: http://paulbakker.io | https://arjanschaaf.github.io Twitter: @pbakker | @arjanschaaf Mail: paul.bakker@luminis.eu | arjan.schaaf@luminis.eu