Breizhcamp 2019

1. Application update in a
Kubernetes world

2. 22
Mathieu Herbert
@MathieuHerbert
mathieuherbert

3. 33
Zero Downtime

4. 44

5. 55

6. 66

7. 77

8. 88
Service Level Agreement
99.999...%

9. 99
Cloud Native Applications

10. 1010

11. 1111
Container Orchestrator
Scheduling / Self Healing / Scalability

12. 1212
Continuous Deployment

13. 1313
Continuous Deployment

14. 1414
• The smallest deployment unit
• One or more containers
• Shared network and storage
POD
metadata:
labels:
app: grid
spec:
containers:
- name: app
image: breizhcamp:v1
ports:
- containerPort: 8080
env:
- name: COLOR
value: "#8bc34a"

15. 1515
• Abstraction which defines a logical set of Pods and a policy by which
to access them
Virtual IP or
Endpoints
spec:
selector:
app: grid
ports:
- protocol: TCP
port: 80
targetPort: 8080
SERVICE

16. 1616
• Meta Object to manage access from outside the cluster
INGRESS
- host: breizhcamp.tes
http:
paths:
- path: /
backend:
serviceName: grid
servicePort: 80
grid

17. 1717
INGRESS CONTROLLER TRAEFIK
Traffic Incoming

18. 1818
INGRESS CONTROLLER TRAEFIK
Watch Ingress API
Traffic Incoming
breizhcamp.tes
myapp.com
wonderfull.com

19. 1919
INGRESS CONTROLLER TRAEFIK
Watch Ingress API
Route traffic to the
right pod
Traffic Incoming
breizhcamp.tes
myapp.com
wondefull.com

20. 2020

21. 2121
• Simple to configure
• Manage SSL termination
• Rewrite URL
• Fully compatible with Kubernetes (Namespace, ingress API)
• Circuit Breaker
• …
TRAEFIK

22. 2222
ARCHITECTURE
Namespace applications Namespace administration
App A App B

23. 2323
helm install stable/traefik traefik
TRAEFIK INSTALLATION (THROUGH HELM)

24. 2424

25. 2525
DEFAULT UPGRADE - ROLLING UPDATE
Replace pod by pod with the new version

26. 2626
• ReplicaSet ensure the number of required pod at any time
REPLICASET
replicas: 3
template:
spec:
containers:
- name: app
image: breizhcamp:v1
ports:
- containerPort: 8080
env:
- name: COLOR
value: "#8bc34a"

27. 2727
• Abstraction to manage ReplicaSet.
DEPLOYMENT spec:
replicas: 3
strategy:
type: RollingUpdate
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
template:
metadata:
labels:
app: grid
spec:
containers:
- name: app
...

28. 2828

29. 2929

30. 3030
kind: Deployment
metadata:
name: grid
spec:
replicas: 3
strategy:
type: RollingUpdate
template:
spec:
containers:
- name: app
image: breizhcamp:v2

31. 3131

32. 3232

33. 3333

34. 3434

35. 3535

36. 3636

37. 3737

38. 3838

39. 3939

40. 4040
Demo

41. 4141

42. 4242
Rolling update must be well
managed and understood

43. 4343
BLUE - GREEN DEPLOYMENT
One Active environment / One Inactive

44. 4444

45. 4545

46. 4646
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: grid
spec:
rules:
- host: breizhcamp.tes
http:
paths:
- backend:
serviceName: grid-blue
servicePort: 80

47. 4747

48. 4848

49. 4949
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: grid
spec:
rules:
- host: breizhcamp.tes
http:
paths:
- backend:
serviceName: grid-green
servicePort: 80

50. 5050

51. 5151
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: grid
spec:
rules:
- host: breizhcamp.tes
http:
paths:
- backend:
serviceName: grid-blue
servicePort: 80

52. 5252

53. 5353

54. 5454

55. 5555

56. 5656
Demo

57. 5757
Can be done at service
level

58. 5858

59. 5959

60. 6060
Update/rollback
instantaneous

61. 6161

62. 6262
2 versions at the same time

63. 6363
CANARY RELEASE
Reduce the risk when releasing new version

64. 6464

65. 6565

66. 6666
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/service-weights: |
grid-blue: 100
grid-green: 0
name: grid
...

67. 6767

68. 6868
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/service-weights: |
grid-blue: 80
grid-green: 20
name: grid
...

69. 6969

70. 7070
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/service-weights: |
grid-blue: 60
grid-green: 40
name: grid
...

71. 7171

72. 7272
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/service-weights: |
grid-blue: 20
grid-green: 80
name: grid
...

73. 7373

74. 7474
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/service-weights: |
grid-blue: 0
grid-green: 100
name: grid
...

75. 7575

76. 7676

77. 7777

78. 7878
Demo

79. 7979
New slide with each update
/ pro/cons
Type Rolling update Blue Green Canary Release
Pros
Easy to implement
not costly
Instantaneous
Update/Rollback
Manage the
increment to deploy a
new version
Cons
2 versions seen at the
same time by users
Infrastructure
cost
Infrastructure cost ?
(can be handle by
pod autoscaling)
2 versions seen at the
same time by users

80. 8080
POD AUTOSCALER
...
min replicas / max replicas

81. 8181
New slide with each update
/ pro/cons
Type Rolling update Blue Green Canary Release
Pros
Easy to implement
not costly
Instantaneous
Update/Rollback
Manage the
increment to deploy a
new version
Cons
2 versions seen at the
same time by users
Infrastructure
cost
Infrastructure cost ?
(can be handle by
pod autoscaling)
2 versions seen at the
same time by users

82. 8282
SESSION AFFINITY WITH TRAEFIK
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/affinty: true
name: grid
...
• A cookie is set on the initial
request with the information
of the backend of the first
request
• If the backend is still healthy
new request will be sent to the
same backend

83. 8383
CIRCUIT BREAKER WITH TRAEFIK
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
traefik.ingress.kubernetes.io/circuit-breaker
-expression: ResponseCodeRatio(500, 600, 0,
600) > 0.5
name: grid
...
Circuit breaker expression
• NetworkErrorRatio() > 0.5
• LatencyAtQuantileMS(50.0) > 50 (in
ms)
• ResponseCodeRatio(500, 600, 0, 600)
> 0.5

84. 8484

85. 8585
Traffic Incoming

86. 8686
Traffic Incoming
LB

87. 8787
MONITORING

88. 8888
MONITORING
New version

89. 8989
MONITORING Alert
Threshold

90. 9090
OK but ...

91. 9191
Data migration ?
functional validation ?
API breaking changes ?
...

92. 9292

93. 3 points

94. 1. Monitoring
on Application / Ingress Controller / Cluster

95. 2. Take time on IaC
KISS and YAGNI patterns

96. 3. Update frequently
with Rolling Update / Blue Green / Canary Release

97. KUBERNETES / TRAEFIK
APPLICATION UPDATE