Kubernetes Overview @ Kubernetes Meetup Mumbai

Transcript

1. Kubernetes & Google Container Engine Overview Kubernetes Meetup Mumbai
2. Confidential & Proprietary Google Cloud Platform 2 Ian Lewis Developer Advocate - Google Cloud Platform Tokyo, Japan @IanMLewis
3. For the last 15 years Google has been building the world’s fastest, most powerful infrastructure.
4. Google’s World Spanning Backbone Network
6. Building what’s next 6 33 Countries 70 Edge Locations The most of any Cloud Provider Google-Grade Networking
7. Monitoring Mobile Development Compute Network Big Data Storage
8. 2012 2015 MapReduce Spanner 2003 2006 2010 2011 GFS Borg Colossus Dremel Bigtable Chubby 2004
9. Copyright 2015 Google Inc Google has been running all our services in Containers for 10 years. We start over 2 billion containers every week. Images by Connie Zhou
10. http://research.google.com/pubs/pub43438.html
11. Image by Connie Zhou
12. job hello_world = { runtime = { cell = 'ic' } // Cell (cluster) to run in binary = '.../hello_world_webserver' // Program to run args = { port = '%port%' } // Command line parameters requirements = { // Resource requirements ram = 100M disk = 100M cpu = 0.1 } replicas = 5 // Number of tasks } 10000 Developer View
13. Developer View
14. web browsers BorgMaster link shard UI shard BorgMaster link shard UI shard BorgMaster link shard UI shard BorgMaster link shard UI shard Scheduler borgcfg web browsers scheduler Borglet Borglet Borglet Borglet Config file BorgMaster link shard UI shard persistent store (Paxos) Binary Developer View What just happened?
15. Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Image by Connie Zhou Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world! Hello world!
16. Container Image Dependencies Application Code Containers encapsulate application code and all dependencies. Applications can be depend less on the infrastructure where it runs. • In traditional IT environments, applications needed specific infrastructure. Dependencies needed to be installed beforehand. • Containers incorporate applications and their dependencies so deployment to development, test, and production can be made easier. • Don’t need to be dependent on on-premise, private or public cloud environments. What are Containers?
17. Fast Simple and Fast compared to VMs. Can be started in just a few milliseconds. Portable Can be run in a many environments. Efficiency Low overhead. Resources use by containers can be limited. Why Containers?
19. Copyright 2015 Google Inc Container Management Node Node Cluster Node ??? • How to deploy to multiple nodes? • How to deal with node failures? • How to deal with container failures? • How do you update your applications?
20. Kubernetes κυβερνήτης: Greek for “pilot” or “helmsman of a ship” the open source cluster manager from Google
21. CNCF(Cloud Native Computing Foundation)
22. Google Cloud Platform Goal: Avoid vendor lock-in Runs in many environments, including “bare metal” and “your laptop” The API and the implementation are 100% open The whole system is modular and replaceable Workload portability
23. Google Cloud Platform Goal: Write once, run anywhere* Don’t force apps to know about concepts that are cloud-provider-specific Examples of this: • Network model • Ingress • Service load-balancers • PersistentVolumes * approximately Workload portability
24. Google Cloud Platform Goal: Avoid coupling Don’t force apps to know about concepts that are Kubernetes-specific Examples of this: • Namespaces • Services / DNS • Downward API • Secrets / ConfigMaps Workload portability
25. Google Cloud Platform Result: Portability Build your apps on-prem, lift-and-shift into cloud when you are ready Don’t get stuck with a platform that doesn’t work for you Put your app on wheels and move it whenever and wherever you need Workload portability
26. Container Engine Google Cloud Platform
27. Google Cloud Platform UI CLI API users master nodes etcd scheduler controllers master The 10000 Foot View kubelet kubelet kubelet kubelet kubelet kubelet kubelet kubelet kubelet
28. Google Cloud Platform The 10000 Foot View etcd scheduler controller-manager apiserver kubelet docker kube-proxy iptables 1. User creates Deployment 2. API server saves info to etcd 3. CM finds Deployment and creates ReplicaSet, which creates Pods (unscheduled) 4. Scheduler schedules pods. 5. Kubelet sees pod scheduled to it and tells docker to run the container. 6. Docker pulls and runs the container. 1 2 6 3 5 4 Docker Hub / GCR 1. Deployment 2. ReplicaSet 3. etc.
29. Google Cloud Platform Small group of containers & volumes Tightly coupled The atom of scheduling & placement Shared namespace • share IP address & localhost • share IPC, etc. Managed lifecycle • bound to a node, restart in place • can die, cannot be reborn with same ID Example: data puller & web server Consumers Content Manager File Puller Web Server Volume Pod Pods
30. Google Cloud Platform Docker Containers IPC Network PID Hostname Mount nginx IPC Network PID Hostname Mount nginx IPC Network PID Hostname Mount nginx
31. Google Cloud Platform IPC Network PID Hostname Mounts nginx IPC Network PID Hostname Mount git pull IPC Network PID Hostname Mount nginx Docker Containers
32. Google Cloud Platform IPC Network PID Hostname Mounts nginx IPC Network PID Hostname Mount git pull IPC Network PID Hostname Mount nginx Docker Containers VOLUME VOLUME Host Volume
33. Google Cloud Platform Host NIC Network IPC Network PID Hostname Mounts nginx IPC Network PID Hostname Mount git pull IPC Network PID Hostname Mount nginx Docker Containers NAT NAT
34. Google Cloud Platform 172.16.1.1 172.16.1.2 172.16.1.1 172.16.1.1 NAT NAT NAT NAT NAT Docker networking
35. Google Cloud Platform A: 172.16.1.1 3306 B: 172.16.1.2 80 9376 11878 SNAT SNAT C: 172.16.1.1 8000 Port mapping
36. Google Cloud Platform Pods & Docker? confd nginx HUP W RITE READ etcd CHANGE nginx.conf app app app IP Address LB
37. Google Cloud Platform Container Container Pods & Docker? confd nginx HUP W RITE READ etcd CHANGE ? ? ? ?
38. Google Cloud Platform Pods & Docker? Container nginx confd foreman
39. Google Cloud Platform Container foreman Pods & Docker? nginx confd
40. Google Cloud Platform Container foreman Pods & Docker? Everything’s A-OK!! nginx confd Crash-Restart Loop
41. Google Cloud Platform IPC Network Pods docker … --net=container:id --ipc=container:id Hostname cgroup Web Server Pod cgroup File Puller localhost
42. Google Cloud Platform Pods (TODO) docker … --net=container:id --ipc=container:id --pid=container:id https://github.com/docker /docker/issues/10163 IPC Network PID Hostname cgroup Web Server cgroup File Puller localhost
43. Google Cloud Platform IPs are cluster-scoped • vs docker default private IP Pods can reach each other directly • even across nodes No brokering of port numbers • too complex, why bother? This is a fundamental requirement • can be L3 routed • can be underlayed (cloud) • can be overlayed (SDN) Kubernetes networking
44. Google Cloud Platform 10.1.1.0/24 10.1.1.1 10.1.1.2 10.1.2.0/24 10.1.2.1 10.1.3.0/24 10.1.3.1 Kubernetes networking
45. Google Cloud Platform Goal: manage app configuration • ...without making overly-brittle container images 12-factor says config comes from the environment • Kubernetes is the environment Manage config via the Kubernetes API Inject config as a virtual volume into your Pods • late-binding, live-updated (atomic) • also available as env vars Status: GA in Kubernetes v1.2 node API Pod Config Map ConfigMaps
46. Google Cloud Platform Goal: grant a pod access to a secured something • don’t put secrets in the container image! 12-factor says config comes from the environment • Kubernetes is the environment Manage secrets via the Kubernetes API Inject secrets as virtual volumes into your Pods • late-binding, tmpfs - never touches disk • also available as env vars node API Pod Secret Secrets
47. Google Cloud Platform A higher-level storage abstraction • insulation from any one cloud environment Admin provisions them, users claim them • NEW: auto-provisioning (alpha in v1.2) Independent lifetime from consumers • lives until user is done with it • can be handed-off between pods Dynamically “scheduled” and managed, like nodes and pods Claim PersistentVolumes
48. Google Cloud Platform Cluster Admin PersistentVolumes
49. Google Cloud Platform Provision Cluster Admin PersistentVolumes PersistentVolumes
50. Google Cloud Platform User Cluster Admin PersistentVolumes PersistentVolumes
51. Google Cloud Platform User PVClaim Create Cluster Admin PersistentVolumes PersistentVolumes
52. Google Cloud Platform User PVClaim Binder Cluster Admin PersistentVolumes PersistentVolumes
53. Google Cloud Platform User PVClaim Pod Create Cluster Admin PersistentVolumes PersistentVolumes
54. Google Cloud Platform User PVClaim Pod Cluster Admin PersistentVolumes * PersistentVolumes
55. Google Cloud Platform User PVClaim Pod Delete * Cluster Admin PersistentVolumes * PersistentVolumes
56. Google Cloud Platform User PVClaim Cluster Admin PersistentVolumes * PersistentVolumes
57. Google Cloud Platform User PVClaim Pod Create Cluster Admin PersistentVolumes * PersistentVolumes
58. Google Cloud Platform User PVClaim Pod Cluster Admin PersistentVolumes * PersistentVolumes
59. Google Cloud Platform User PVClaim Pod Delete Cluster Admin PersistentVolumes * PersistentVolumes
60. Google Cloud Platform User PVClaim Delete Cluster Admin PersistentVolumes * PersistentVolumes
61. Google Cloud Platform User Recycler Cluster Admin PersistentVolumes PersistentVolumes
62. Google Cloud Platform Deployments ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 Deployment - name: MyApp kubectl create ...
63. Google Cloud Platform Deployments ReplicaSet - replicas: 4 - selector: - app: MyApp - version: v1 Deployment - name: MyApp kubectl create ...
64. Google Cloud Platform Deployments ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 Deployment - name: MyApp kubectl create ...
65. Google Cloud Platform Deployments ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 Deployment - name: MyApp kubectl create ...
66. Google Cloud Platform Rolling Updates ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 Deployment - name: MyApp kubectl apply ...
67. Google Cloud Platform ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 Rolling Updates ReplicaSet - replicas: 0 - selector: - app: MyApp - version: v2 Deployment - name: MyApp
68. Google Cloud Platform ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v1 ReplicaSet - replicas: 1 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
69. Google Cloud Platform ReplicaSet - replicas: 2 - selector: - app: nginx - ver: 1.10 ReplicaSet - replicas: 1 - selector: - app: nginx - ver: 1.11 Deployment - app: nginx Rolling Updates
70. Google Cloud Platform ReplicaSet - replicas: 2 - selector: - app: MyApp - version: v1 ReplicaSet - replicas: 2 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
71. Google Cloud Platform ReplicaSet - replicas: 1 - selector: - app: MyApp - version: v1 ReplicaSet - replicas: 2 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
72. Google Cloud Platform ReplicaSet - replicas: 1 - selector: - app: MyApp - version: v1 ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
73. Google Cloud Platform ReplicaSet - replicas: 0 - selector: - app: MyApp - version: v1 ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
74. Google Cloud Platform ReplicaSet - replicas: 3 - selector: - app: MyApp - version: v2 Rolling Updates Deployment - name: MyApp
75. Google confidential │ Do not distribute Services A group of pods that work together • grouped by a selector Defines access policy • “load balanced” or “headless” Gets a stable virtual IP and port • sometimes called the service portal • also a DNS name VIP is managed by kube-proxy • watches all services • updates iptables when backends change Hides complexity - ideal for non-native apps Virtual IP Client
76. Google Cloud Platform Arbitrary metadata Attached to any API object Generally represent identity Queryable by selectors • think SQL ‘select ... where ...’ The only grouping mechanism • pods under a ReplicationController • pods in a Service • capabilities of a node (constraints) Labels
77. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE Selectors
78. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE App = MyApp Selectors
79. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE App = MyApp, Role = FE Selectors
80. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE App = MyApp, Role = BE Selectors
81. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE App = MyApp, Phase = prod Selectors
82. Google Cloud Platform App: MyApp Phase: prod Role: FE App: MyApp Phase: test Role: FE App: MyApp Phase: prod Role: BE App: MyApp Phase: test Role: BE App = MyApp, Phase = test Selectors
83. Google Cloud Platform Run-to-completion, as opposed to run-forever • Express parallelism vs. required completions • Workflow: restart on failure • Build/test: don’t restart on failure Aggregates success/failure counts Built for batch and big-data work Status: GA in Kubernetes v1.2 ... Jobs
84. Google Cloud Platform Problem: I have too much stuff! • name collisions in the API • poor isolation between users • don’t want to expose things like Secrets Solution: Slice up the cluster • create new Namespaces as needed • per-user, per-app, per-department, etc. • part of the API - NOT private machines • most API objects are namespaced • part of the REST URL path • Namespaces are just another API object • One-step cleanup - delete the Namespace • Obvious hook for policy enforcement (e.g. quota) Namespaces
85. slack.kubernetes.io
86. Thank You