- Kubernetes Concepts - Hands on: Using kubeadm to stand up a Kubernetes cluster - Hands on: Using kubectl to make changes to running Kubernetes cluster

1. Orchestrating Microservices
with Kubernetes
Jeff Hoffer, Developer Experience
github.com/eudaimos

2. What does Weave do?
Weave helps devops
iterate faster with:
• observability &
monitoring
• continuous delivery
• container networks
& firewalls
Kubernetes is our #1
platform

3. Agenda
1. Concepts
2. Containers, Pods, Deployments, Services
3. Installing Kubernetes
4. Demos of Pods, Deployments, Services
5. Microservices sample app
6. What’s next?

4. Kubernetes: all you need to know
Pods
containers
Services
Deployments

5. Concepts
Computer

6. Concepts
Node

7. Concepts
nginx Container
image: nginx:1.7.9
Node

8. web
Concepts
nginx Container
Pod
logger
Node

9. web
Concepts
nginx Container
Pod
logger
IP addr
Node

10. web
Concepts
Podnginx
apiVersion: v1
kind: Pod
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
Node

11. Recap: all you need to know
Pods
containers
Container
Image
Docker container image, contains your application code in an isolated
environment.
Pod A set of containers, sharing network namespace and local volumes,
co-scheduled on one machine. Mortal. Has pod IP. Has labels.

12. Motivation for Deployments
Node 1
Pod
web
nginx
Node 2

13. Motivation for Deployments
Pod
web
nginx
Node 1 Node 2

14. Motivation for Deployments
Pod
web
nginx
Node 1 Node 2

15. Deployment
web
nginx
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
Node 1

16. Deployment
web
nginx
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
Node 1

17. Deployment
web
nginx
Node 1 Node 2

18. Deployment
web
nginx
Node 1 Node 2

19. Deployment
web
nginx
Node 1 Node 2

20. Deployment
web
nginx
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
Node 1

21. Deployment
web
nginx
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
Node 1

22. Deployment
web
nginx
web
nginx
Node 1 Node 2

23. Recap: all you need to know
Pods
containers
Deployments
Container
Image
Docker container image, contains your application code in an isolated
environment.
Pod A set of containers, sharing network namespace and local volumes,
co-scheduled on one machine. Mortal. Has pod IP. Has labels.
Deployment Specify how many replicas of a pod should run in a cluster. Then
ensures that many are running across the cluster.

24. Service discovery
• Kubernetes provides DNS for service
discovery

25. Service discovery
• Kubernetes provides DNS for service
discovery
WAIT! You said “service”.
What is a service?

26. Services: ClusterIP (internal things)
Computer 1
web
ruby
Computer 2
10.0.0.1
db
pgsql
10.0.0.2
service VIP
10.1.0.1DNS lookup “db”
returns A 10.1.0.1

27. Services: ClusterIP (internal things)
Computer 1
web
ruby
Computer 2
10.0.0.1
db
pgsql
10.0.0.2
service VIP
10.1.0.1

28. Services: NodePort (external)
Computer 1
web
nginx
web
nginx
10.0.0.1 10.0.0.2
81.23.64.18 81.23.64.19
requests requests
Computer 2

29. Computer 1
web
nginx
web
nginx
10.0.0.1 10.0.0.2
81.23.64.18 81.23.64.19
requests requests
Computer 2
Services: NodePort (external)
NodePort 30001
service VIP
10.1.0.1
NodePort 30001
service VIP
10.1.0.1

30. Computer 1
web
nginx
web
nginx
10.0.0.1 10.0.0.2
81.23.64.18 81.23.64.19
requests requests
Computer 2
Services: NodePort (external)
NodePort 30001
service VIP
10.1.0.1
NodePort 30001
service VIP
10.1.0.1

31. kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
kind: Service
metadata:
name: frontend
spec:
type: NodePort
selector:
app: nginx
ports:
- port: 80
targetPort: 80
nodePort: 30002
Using selectors
How do services connect to deployments?
matches

32. kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 2
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
kind: Service
metadata:
name: frontend
spec:
type: NodePort
selector:
app: nginx
ports:
- port: 80
targetPort: 80
nodePort: 30002
How do you expose services to outside?
Using NodePort

33. Recap: all you need to know
Pods
containers
ServicesDeployments
Container
Image
Docker container image, contains your application code in an isolated
environment.
Pod A set of containers, sharing network namespace and local volumes,
co-scheduled on one machine. Mortal. Has pod IP. Has labels.
Deployment Specify how many replicas of a pod should run in a cluster. Then
ensures that many are running across the cluster. Has labels.
Service Names things in DNS. Gets virtual IP. Two types: ClusterIP for internal
services, NodePort for publishing to outside. Routes based on labels.

34. Architecture of Kubernetes itself
Node 1 Node 2
Master

35. API server
Architecture of Kubernetes itself
Node 1 Node 2
Master
API server etcd
kubeadm init

36. API server
Architecture of Kubernetes itself
Node 1 Node 2
Master
API server etcd
kubeadm init
kubeadm join
kubelet

37. API server
Architecture of Kubernetes itself
Node 1 Node 2
Master
API server etcd
kubeadm init
kubeadm join kubeadm join
kubelet kubelet

38. API server
Architecture of Kubernetes itself
Node 1 Node 2
Master
API server etcd
kubeadm init
kubeadm join kubeadm join
kubelet kubelet
kubectl apply

39. API server
Architecture of Kubernetes itself
Node 1 Node 2
Master
containers
Services
containers
API server etcd
kubeadm init
kubeadm join kubeadm join
kubectl apply
kubelet kubelet

40. Training!

41. Join the Weave user group!
meetup.com/pro/Weave/
weave.works/help

42. What’s next?
• Continuous delivery: hooking up my CI/CD
pipeline to Kubernetes
• How do I monitor this stuff?
• Network policy for security
Come to our Weave Cloud training to find out!

43. Thanks! Questions?
We are hiring!
DX in San Francisco
Engineers in London & SF
weave.works/weave-company/hiring