Speech about scaling microservices with Kubernetes

1. Scaling Microservices
with Kubernetes

2. Deivid Hahn Fração
Web Developer

3. Containers

4. Microservices
Challenges
▸ Infrastructure complexity
▸ Scaling
▸ Service discovery and routing
▸ Monitoring and logging

5. Solution

6. What is
Kubernetes?
"Kubernetes is an open-source
system for automating
deployment, scaling, and
management of containerized
applications."

7. What is
Kubernetes?
▸ Also known as k8s
▸ Inspired by the Google Borg system
▸ V1.0 released in July 2015
▸ Google donated it to the Cloud
Native Computing Foundation

8. Kubernetes
is...
▸ Portable: public, private, hybrid,
multi-cloud
▸ Extensible: modular, pluggable,
hookable, composable
▸ Self-healing: auto-placement,
auto-restart, auto-replication,
auto-scaling

9. Architecture

10. Kubectl
▸ Command line interface for running
commands against Kubernetes
clusters

11. Dashboard

12. Minikube
▸ Minikube is a tool that makes it
easy to run Kubernetes locally
▸ It runs a single-node
Kubernetes cluster inside a VM

13. Components

15. Master
Components

16. ▸ Exposes the Kubernetes API
▸ REST operations
▸ It is the front-end for the
Kubernetes control plane
kube-apiserver

17. ▸ Kubernetes’ backing store
▸ All cluster data is stored
here
▸ A multi-node cluster in
production and back it up
periodically is
recommended.
etcd

18. ▸ Watches newly created
pods that have no node
assigned
▸ Selects the best node
option for them to run
kube-scheduler

19. ▸ Run controllers that handle
routine tasks
kube-controller-manager
cloud-controller-manager
▸ Run controllers that interact
with cloud providers

20. Node
Components

21. ▸ It watches for pods that
have been assigned to its
node
▸ Runs the pod and mount
required volumes
▸ Downloads the pod’s
secrets
▸ Reports the status of the
node back to the rest of the
system
kubelet

22. ▸ Maintain network rules
kube-proxy

23. Concepts

24. Desired
State
▸ Very important concept in
the Kubernetes model
▸ It is Kubernetes’
responsibility to make sure
that the current state
matches the desired state

25. Pod
▸ It contains one or more
application containers,
tightly coupled
▸ Containers within a pod
share an IP address and port
space, and can find each
other via localhost

26. Pod
▸ Pods are considered to be
relatively ephemeral
▸ Normally used with
controllers

27. How to
create
a Pod?

28. How to
create
a Pod?

29. How to
create
a Pod?

30. Describing
a Pod

31. Describing
a Pod

32. Describing
a Pod

33. Label
▸ Labels are key/value pairs
that are attached to objects,
such as pods
▸ Labels can be used to
organize and to select
subsets of objects

34. Liveness
Probe
▸ The kubelet uses liveness
probes to know when to
restart a Container

35. Liveness
Probe

36. Readiness
probe
▸ The kubelet uses readiness
probes to know when a
Container is ready to start
accepting traffic
▸ A Pod is considered ready
when all of its Containers are
ready
▸ When a Pod is not ready, it is
removed from Service load
balancers

37. Readiness
probe

38. Readiness
/ liveness
probe
fields
▸ initialDelaySeconds: Number
of seconds after the
container has started before
liveness or readiness probes
are initiated
▸ periodSeconds: How often
(in seconds) to perform the
probe

39. Readiness
/ liveness
probe
fields
▸ successThreshold: Minimum
consecutive successes for
the probe to be considered
successful after having
failed
▸ failureThreshold: Minimum
consecutive failures for the
probe to be considered
unhealthy

40. ▸ Pods are mortal
▸ Each Pod has a unique IP
address, but those IPs are
not exposed outside the
cluster.
▸ A service defines a logical
set of Pods and a policy by
which to access them
Services

41. ▸ ClusterIP (default): Exposes
the Service on an internal IP
in the cluster
▸ NodePort: Exposes the
Service on the same port of
each selected Node in the
cluster
Services
- Types

42. ▸ LoadBalancer - Creates an
external load balancer in the
current cloud (if supported)
and assigns a fixed, external
IP to the Service
▸ ExternalName - Exposes the
Service using an arbitrary
name (e.g.
test.example.com)
Services
- Types

43. Services

44. Replication
Controller
▸ Replication Controller
ensures that a specified
number of pod replicas are
running at any one time
▸ If there are too many pods,
the ReplicationController
terminates the extra pods. If
there are too few, the
ReplicationController starts
more pods.

45. Replication
Controller

46. Replication
Controller

47. Replication
Controller

48. Replication
Controller

49. Replica
Set
▸ Next-generation Replication
Controller
▸ The difference between a
ReplicaSet and a Replication
Controller right now is the
selector support

50. Replica
Set

51. Replica
Set

52. Replica
Set

53. Deployments
▸ A Deployment controller
provides declarative updates
for Pods and ReplicaSets
▸ Recommended way

54. Deployments

55. Deployments

56. Deployments

57. Deployments

58. Deployments

59. Deployments

60. Namespace
▸ Namespaces are intended
for use in environments with
many users spread across
multiple teams, or projects
▸ Names of resources need to
be unique within a
namespace, but not across
namespaces

61. Namespace

62. Secrets
▸ Passwords, OAuth tokens,
and ssh keys
▸ A secret can be used with a
pod in two ways: as files in a
volume mounted on one or
more of its containers, or
used by kubelet when pulling
images for the pod

63. Secrets

64. Secrets in
a Pod

65. Using Secrets
as
Environment
Variables

66. ConfigMap
▸ Key-value pairs of
configuration data that can
be consumed in pod
▸ ConfigMap is similar to
Secrets, but it do not contain
sensitive information

68. THANKS!