Kubernets cluster in Azure cloud

Kubernets config

Use Declarative, we declare the state and kubectl implements using
```
kubectl apply -R -f configs/
```

Setup Cluster, using the Azure az commands and azure aks install-cli kubectl

Use az tool, with docker run -it microsoft/azure-cli

in the container add the kubectl

az aks install-cli
az aks get-credentials --resource-group <RG> --name <name> --subscription <Hex-ID>

list subscriptions
```
az account list --output table 
```
set subscription to the one that contains k8s
```
az account set --subscription xx-xx-xx
```

run az proxy to connect the browser to kubernets admin in cloud

Proxy running on http://127.0.0.1:8001/
Press CTRL+C to close the tunnel...
Forwarding from 127.0.0.1:8001 -> 9090

## Problem only binds to loopback, in a container, if not using container for microsoft/azure-cli skip next command.
nc -v -lk -p 8001 -s $(hostname -i) -e /usr/bin/nc 127.0.0.1 8001

## Web dashboard no right - nodes is forbidden: User "system:serviceaccount:kube-system:kubernetes-dashboard" cannot list nodes at the cluster scope
## RBAC ClusterRoleBinding must be created for Kubernetes dashboard
kubectl create clusterrolebinding kubernetes-dashboard \
    --clusterrole=cluster-admin \
    --serviceaccount=kube-system:kubernetes-dashboard

List nodes

kubectl get nodes

If this fails with "Unable to connect to the server: dial tcp: lookup ...." reset with

rm .kube/config
az aks get-credentials --resource-group <nameRG> --name >nameClusterInRG>
kubectl get nodes

List namespaces
```
kubectl get namespaces
```

Reset ssh key and password to get access to k8s Node in Azure 2020-05

reset ssh key and password

AZ_RG=aks-<xxxx>-nodes
AZ_SUBSCRIPTION="xxx"
RANDOM_PWD=$( ( head /dev/urandom ; date +%s) | sha256sum | base64 | head -c32 )

SCALE_SET_NAME=$(az vmss list --resource-group $AZ_RG --subscription "$AZ_SUBSCRIPTION" --query [0].name -o tsv)
echo "SCALE_SET_NAME=$SCALE_SET_NAME  RANDOM_PWD=$RANDOM_PWD  AZ_SUBSCRIPTION=$AZ_SUBSCRIPTION"


az vmss extension set --resource-group "$AZ_RG" --vmss-name "$SCALE_SET_NAME" --name VMAccessForLinux --publisher Microsoft.OSTCExtensions --version 1.4 --protected-settings "{\"reset_ssh\": true, \"username\": \"azureuser\", \"password\": \"$RANDOM_PWD\", \"ssh_key\": \"$(cat ~/.ssh/id_rsa.pub)\"}"

( set -x ; az vmss update-instances --instance-ids '*' --resource-group "$AZ_RG" --name "$SCALE_SET_NAME" )

Then get the ip of the node with $ kubectl get nodes -o wide

Launch container in k8s cluster

$ kubectl run -i --tty --rm MyContainer -generator="run-pod/v1" --image=debian /bin/bash
# apt-get update && apt-get install openssh-client -y

Copy pvt ssh key into container $ kubectl cp ~/.ssh/id_rsa MyContainer-xxx:/id_rsa
ssh to node. # ssh -i /id_rsa azureuser@10.240.0.x

Test

az - setup proxy tunnel to web admin

az aks get-credentials --resource-group K8S-xxx --name K8S-xxx
```
Merged "K8S-INF" as current context in /root/.kube/config 
```
kubectl get nodes
Create azure-vote.yml from https://docs.microsoft.com/en-us/azure/aks/kubernetes-walkthrough

kubectl apply -f azure-vote.yaml

deployment.apps/azure-vote-back created
service/azure-vote-back created
deployment.apps/azure-vote-front created
service/azure-vote-front created
bash-4.4#

kubectl get service azure-vote-front --watch

NAME               TYPE           CLUSTER-IP   EXTERNAL-IP     PORT(S)        AGE
azure-vote-front   LoadBalancer   10.0.61.46   1.5.1.39        80:31745/TCP   101s

Own namespace

Created with json file that gets deployed

Set default namespace to mynamespace e.g.

# kubectl config set-context $(kubectl config current-context) --namespace=MyNameSpace
# kubectl config view | grep namespace

Perf monitoring

kubectl top nodes
kubectl describe nodes
kubectl top pod
Prometheus - https://github.com/google-cloud-tools/kube-eagle

AZ check clusters and PSP/NetPolicy

export azure subscription and run

export azsub=--subscription \"Non-Prod\" "
az aks list $azsub | jq "[ .[] | 
        {name: .name, k8sV: .kubernetesVersion,
         sp: .servicePrincipalProfile.clientId,
         NetPolicy: .networkProfile.networkPolicy,
         Nodes: ((.agentPoolProfiles[0].count|tostring) + \"/\" + ( .agentPoolProfiles[0].maxCount|tostring ) + \" \" + .agentPoolProfiles[0].provisioningState),
         psp: .enablePodSecurityPolicy,
         rbac: .enableRbac,
         apiAuth: .apiServerAccessProfile.authorizedIpRanges,
         }]"

...

CategoryK8sKubernetes CategoryK8sKubernetes