Difference between revisions of "Kubernetes/Amazon EKS"

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Line 324: Line 324:
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/backend-policy.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/backend-policy.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/frontend-policy.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/frontend-policy.yaml
</source>


Backend and forntend policies
{| class="wikitable"
|+ Read a file or variable line by line
|-
! backend-policy
! frontend-policy
|-
| <source lang="bash">
$ cat backend-policy.yaml:
$ cat backend-policy.yaml:
kind: NetworkPolicy
kind: NetworkPolicy
Line 344: Line 353:
           port: 6379
           port: 6379
</source>
</source>
| <source lang="bash">
$ cat frontend-policy.yaml
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  namespace: stars
  name: frontend-policy
spec:
  podSelector:
    matchLabels:
      role: frontend
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              role: client
      ports:
        - protocol: TCP
          port: 80
</source>
|}
Apply policies
<source lang="bash">
# allow traffic from frontend service to the backend service apply the manifest
kubectl apply -f backend-policy.yaml
# allow traffic from the client namespace to the frontend service
kubectl apply -f frontend-policy.yaml
</source>
Let’s have a look at the backend-policy. Its spec has a podSelector that selects all pods with the label <code>role:backend</code>, and allows ingress from all pods that have the label role:frontend and on TCP port '''6379''', but not the other way round. Traffic is allowed in one direction on a specific port number.
The frontend-policy is similar, except it allows ingress from '''namespaces''' that have the label <code>role: client</code> on TCP port '''80'''.


= References =
= References =
*[https://eksworkshop.com eksworkshop] Official Amazon EKS Workshop
*[https://eksworkshop.com eksworkshop] Official Amazon EKS Workshop

Revision as of 18:20, 24 November 2018

Bootstrap/create EKS Cluster

# Generate ssh key to be used to connect to Kubernetes EKS Ec2 worker instances
ssh-keygen

# Install kubectl
mkdir -p ~/.kube
sudo curl --location -o /usr/local/bin/kubectl "https://amazon-eks.s3-us-west-2.amazonaws.com/1.10.3/2018-07-26/bin/linux/amd64/kubectl"
sudo chmod +x /usr/local/bin/kubectl
kubectl version --short --client

# Install aws-iam-authenticator
go get -u -v github.com/kubernetes-sigs/aws-iam-authenticator/cmd/aws-iam-authenticator
sudo mv ~/go/bin/aws-iam-authenticator /usr/local/bin/aws-iam-authenticator
aws-iam-authenticator help

# Install jq
sudo yum -y install jq #Amazon Linux
sudo apt-get jq -y     #Ubuntu

# Configure awscli
rm -vf ${HOME}/.aws/credentials
export AWS_REGION=$(curl -s 169.254.169.254/latest/dynamic/instance-identity/document | jq -r .region)
echo "export AWS_REGION=${AWS_REGION}" >> ~/.bash_profile
aws configure set default.region ${AWS_REGION}
aws configure get default.region

# Install eksctl by Waveworks
curl --location "https://github.com/weaveworks/eksctl/releases/download/latest_release/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
sudo mv -v /tmp/eksctl /usr/local/bin
eksctl version

# Create EKS cluster
$ eksctl create cluster --name=eksworkshop-eksctl --nodes=3 --node-ami=auto --region=${AWS_REGION}
2018-11-24T12:54:41Z [ℹ]  using region eu-west-1
2018-11-24T12:54:42Z [ℹ]  setting availability zones to [eu-west-1b eu-west-1a eu-west-1c]
2018-11-24T12:54:42Z [ℹ]  subnets for eu-west-1b - public:192.168.0.0/19 private:192.168.96.0/19
2018-11-24T12:54:42Z [ℹ]  subnets for eu-west-1a - public:192.168.32.0/19 private:192.168.128.0/19
2018-11-24T12:54:42Z [ℹ]  subnets for eu-west-1c - public:192.168.64.0/19 private:192.168.160.0/19
2018-11-24T12:54:43Z [ℹ]  using "ami-00c3b2d35bdddffff" for nodes
2018-11-24T12:54:43Z [ℹ]  creating EKS cluster "eksworkshop-eksctl" in "eu-west-1" region
2018-11-24T12:54:43Z [ℹ]  will create 2 separate CloudFormation stacks for cluster itself and the initial nodegroup
2018-11-24T12:54:43Z [ℹ]  if you encounter any issues, check CloudFormation console or try 'eksctl utils describe-stacks --region=eu-west-1 --name=eksworkshop-eksctl'
2018-11-24T12:54:43Z [ℹ]  creating cluster stack "eksctl-eksworkshop-eksctl-cluster"
2018-11-24T13:06:38Z [ℹ]  creating nodegroup stack "eksctl-eksworkshop-eksctl-nodegroup-0"
2018-11-24T13:10:16Z [✔]  all EKS cluster resource for "eksworkshop-eksctl" had been created
2018-11-24T13:10:16Z [✔]  saved kubeconfig as "/home/ec2-user/.kube/config"
2018-11-24T13:10:16Z [ℹ]  the cluster has 0 nodes
2018-11-24T13:10:16Z [ℹ]  waiting for at least 3 nodes to become ready
2018-11-24T13:10:47Z [ℹ]  the cluster has 3 nodes
2018-11-24T13:10:47Z [ℹ]  node "ip-192-168-13-5.eu-west-1.compute.internal" is ready
2018-11-24T13:10:47Z [ℹ]  node "ip-192-168-41-230.eu-west-1.compute.internal" is ready
2018-11-24T13:10:47Z [ℹ]  node "ip-192-168-79-54.eu-west-1.compute.internal" is ready
2018-11-24T13:10:47Z [ℹ]  kubectl command should work with "/home/ec2-user/.kube/config", try 'kubectl get nodes'
2018-11-24T13:10:47Z [✔]  EKS cluster "eksworkshop-eksctl" in "eu-west-1" region is ready

# Verify EKS cluster nodes
kubectl get nodes
NAME                                           STATUS    ROLES     AGE       VERSION
ip-192-168-13-5.eu-west-1.compute.internal     Ready     <none>    1h        v1.10.3
ip-192-168-41-230.eu-west-1.compute.internal   Ready     <none>    1h        v1.10.3
ip-192-168-79-54.eu-west-1.compute.internal    Ready     <none>    1h        v1.10.3

# Get info about the cluster
eksctl get cluster --name=eksworkshop-eksctl --region=${AWS_REGION}                       NAME                    VERSION STATUS  CREATED                 VPC                     SUBNETS                SECURITYGROUPS
eksworkshop-eksctl      1.10    ACTIVE  2018-11-24T12:55:28Z    vpc-0c97f8a6dabb11111   subnet-05285b6c692711111,subnet-0a6626ec2c0111111,subnet-0c5e839d106f11111,subnet-0d9a9b34be5511111,subnet-0f297fefefad11111,subnet-0faaf1d3dedd11111   sg-083fbc37e4b011111

Deploy the Official Kubernetes Dashboard

# Deploy dashboard from official config sources. Also can download a files and deploy.
kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml

# Create kube-proxy to enable accedd to the application (dashboard) from Internet
# start the proxy in the background, listen on port 8080, listen on all interfaces, and will disable the filtering of non-localhost requests
kubectl proxy --port=8080 --address='0.0.0.0' --disable-filter=true &
 W1124 14:47:55.308424   14460 proxy.go:138] Request filter disabled, your proxy is vulnerable to XSRF attacks, please be cautious
Starting to serve on [::]:8080


Access dashboard

Generate temporary token to login to dashboard

aws-iam-authenticator token -i eksworkshop-eksctl --token-only

Go to webbrowser, point to kube-proxy and append to the URL following path

/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/

select token sign-in and paste token to login in.

Deploy sample applications

The containers listen on port 3000, and native service discovery will be used to locate the running containers and communicate with them.

# Download deployable sample applications
mkdir ~/environment #place of deployables to EKS, applications, policies etc
cd ~/environment
git clone https://github.com/brentley/ecsdemo-frontend.git
git clone https://github.com/brentley/ecsdemo-nodejs.git
git clone https://github.com/brentley/ecsdemo-crystal.git

### Deploy applications
# NodeJS Backend API
cd ecsdemo-nodejs
kubectl apply -f kubernetes/deployment.yaml
kubectl apply -f kubernetes/service.yaml
kubectl get deployment ecsdemo-nodejs # watch progress

# Crystal Backend API
cd ~/environment/ecsdemo-crystal
kubectl apply -f kubernetes/deployment.yaml
kubectl apply -f kubernetes/service.yaml
kubectl get deployment ecsdemo-crystal

Before deploying frontend application let's see how servive differes between backend and frontend services

kubernetes/service.yaml
frontend service backend service
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-frontend
spec:
  selector:
    app: ecsdemo-frontend
  type: LoadBalancer
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000
apiVersion: v1
kind: Service
metadata:
  name: ecsdemo-nodejs
spec:
  selector:
    app: ecsdemo-nodejs
  type: ClusterIP  <-- this is default
  ports:
   -  protocol: TCP
      port: 80
      targetPort: 3000

Notice there is no need to specific service type describe for backend because the default type is ClusterIP. This Exposes the service on a cluster-internal IP. Choosing this value makes the service only reachable from within the cluster. Thus forntend has type: LoadBalancer

The frontend service will attempt to create ELB thus requires access to the elb service. This is controlled by IAM service role that needs creating if does not exist.

aws iam get-role --role-name "AWSServiceRoleForElasticLoadBalancing" || aws iam create-service-linked-role --aws-service-name "elasticloadbalancing.amazonaws.com"

Deploy frontend service

cd ecsdemo-frontend
kubectl apply -f kubernetes/deployment.yaml
kubectl apply -f kubernetes/service.yaml
kubectl get deployment ecsdemo-frontend

# Get service address
kubectl get service ecsdemo-frontend -o wide
ELB=$(kubectl get service ecsdemo-frontend -o json | jq -r '.status.loadBalancer.ingress[].hostname')
curl -m3 -v $ELB #You can also open this in a webrowser

Scale backend services

kubectl scale deployment ecsdemo-nodejs --replicas=3
kubectl scale deployment ecsdemo-crystal --replicas=3
kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
ecsdemo-crystal    3         3         3            3           38m
ecsdemo-frontend   1         1         1            1           20m
ecsdemo-nodejs     3         3         3            3           40m

# Watch scaling in action
$ i=3; kubectl scale deployment ecsdemo-nodejs --replicas=$i; kubectl scale deployment ecsdemo-crystal --replicas=$i
$ watch -d -n 0.5 kubectl get deployments

Check the browser you should now see traffic flowing to multiple frontend services.

Delete the applications

cd ecsdemo-frontend
kubectl delete -f kubernetes/service.yaml
kubectl delete -f kubernetes/deployment.yaml

cd ecsdemo-crystal
kubectl delete -f kubernetes/service.yaml
kubectl delete -f kubernetes/deployment.yaml

cd ecsdemo-nodejs
kubectl delete -f kubernetes/service.yaml
kubectl delete -f kubernetes/deployment.yaml

Networking using Calico

;Install

Below will install Calico manifest. This creates the daemon sets in the kube-system namespace.

wget https://raw.githubusercontent.com/aws/amazon-vpc-cni-k8s/master/config/v1.2/calico.yaml
kubectl apply -f calico.yaml
kubectl get daemonset calico-node --namespace=kube-system

See more details on the eksworkshop.com website.

Policy demo

Before creating network polices, we will create the required resources.

mkdir calico_resources && cd calico_resources 
wget https://eksworkshop.com/calico/stars_policy_demo/create_resources.files/namespace.yaml
kubectl apply -f namespace.yaml # create namespace

# Download manifest for orher resources
wget https://eksworkshop.com/calico/stars_policy_demo/create_resources.files/management-ui.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/create_resources.files/backend.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/create_resources.files/frontend.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/create_resources.files/client.yaml

kubectl apply -f management-ui.yaml
kubectl apply -f backend.yaml
kubectl apply -f frontend.yaml
kubectl apply -f client.yaml

kubectl get pods --all-namespaces


Resources we created:

  • A namespace called stars
  • frontend and backend replication controllers and services within stars namespace
  • A namespace called management-ui
  • Replication controller and service management-ui for the user interface seen on the browser, in the management-ui namespace
  • A namespace called client
  • client replication controller and service in client namespace

Pod-toPod communication

In Kubernetes, the pods by default can communicate with other pods, regardless of which host they land on. Every pod gets its own IP address so you do not need to explicitly create links between pods. This is demonstrated by the management-ui.

$ cat management-ui.yaml
kind: Service
metadata:
  name: management-ui
  namespace: management-ui
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 9001

# Get Management UI dns name
kubectl get svc -o wide -n management-ui

If you open the URL you see Visual Start of connectiona between PODs B-C-F. The UI here shows the default behavior, of all services being able to reach each other.

Apply network policies

By default all Pods can talk to each other what is not what we shuld allow in produciton environemtns. So, let's apply policies:

cd calico_resources
wget https://eksworkshop.com/calico/stars_policy_demo/apply_network_policies.files/default-deny.yaml

cat default-deny.yaml #not all output showing below
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  name: default-deny
spec:
  podSelector:
    matchLabels: {}

# Create deny policies to followign name spaces 'stars' and 'client'. Web browser won't show anything as UI won't have access to pods.
kubectl apply -n stars -f default-deny.yaml
kubectl apply -n client -f default-deny.yaml

# Create allow policies
wget https://eksworkshop.com/calico/stars_policy_demo/apply_network_policies.files/allow-ui.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/apply_network_policies.files/allow-ui-client.yaml

cat allow-ui.yaml
kind: NetworkPolicy
apiVersion: extensions/v1beta1
metadata:
  namespace: stars
  name: allow-ui
spec:
  podSelector:
    matchLabels: {}
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              role: management-ui

cat allow-ui-client.yaml
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  namespace: client
  name: allow-ui
spec:
  podSelector:
    matchLabels: {}
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              role: management-ui

kubectl apply -f allow-ui.yaml
kubectl apply -f allow-ui-client.yaml
# The website should start showing connection star again but Pods cannot communicate to each other.

Allow Directional Traffic

Network policies in Kubernetes use labels to select pods, and define rules on what traffic is allowed to reach those pods. They may specify ingress or egress or both. Each rule allows traffic which matches both the from and ports sections.

# Download 
cd calico_resources
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/backend-policy.yaml
wget https://eksworkshop.com/calico/stars_policy_demo/directional_traffic.files/frontend-policy.yaml

Backend and forntend policies

Read a file or variable line by line
backend-policy frontend-policy
$ cat backend-policy.yaml:
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  namespace: stars
  name: backend-policy
spec:
  podSelector:
    matchLabels:
      role: backend
  ingress:
    - from:
        - podSelector:
            matchLabels:
              role: frontend
      ports:
        - protocol: TCP
          port: 6379
$ cat frontend-policy.yaml 
kind: NetworkPolicy
apiVersion: networking.k8s.io/v1
metadata:
  namespace: stars
  name: frontend-policy
spec:
  podSelector:
    matchLabels:
      role: frontend
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              role: client
      ports:
        - protocol: TCP
          port: 80

Apply policies

# allow traffic from frontend service to the backend service apply the manifest
kubectl apply -f backend-policy.yaml

# allow traffic from the client namespace to the frontend service
kubectl apply -f frontend-policy.yaml


Let’s have a look at the backend-policy. Its spec has a podSelector that selects all pods with the label role:backend, and allows ingress from all pods that have the label role:frontend and on TCP port 6379, but not the other way round. Traffic is allowed in one direction on a specific port number.

The frontend-policy is similar, except it allows ingress from namespaces that have the label role: client on TCP port 80.

References