rrichards
5/28/2019 - 3:47 PM
Kubernetes vagrant cluster
Completion
install bash-completion package
kubeadm completion bash|tee /etc/bash_completion.d/kubeadm
kubectl completion bash|tee /etc/bash_completion.d/kubectl
Bootstrapping the master node "Kubernetes control panel" :
kubeadm init --apiserver-advertise-address=192.168.205.10 --pod-network-cidr=10.244.0.0/16 --kubernetes-version=v1.6.2
## for calico default is 192.168.0.0/16 for flannel it is 10.244.0.0/16, not sure what needs to be done to vagrant for ips not clash
Ensure that the kubelet was configured to use CNI network plugins:
In Ubuntu 16.04 systemd unit file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf you see it set
Environment="KUBELET_NETWORK_ARGS=--network-plugin=cni --cni-conf-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin"
Deploying Calico on an RBAC enabled cluster, first apply the ClusterRole and ClusterRoleBinding specs:
root@master:~# kubectl apply -f https://docs.projectcalico.org/v2.5/getting-started/kubernetes/installation/rbac.yaml
clusterrole "calico-policy-controller" created
clusterrolebinding "calico-policy-controller" created
clusterrole "calico-node" created
clusterrolebinding "calico-node" created
Install Calico
root@master:~# curl -LO https://docs.projectcalico.org/v2.5/getting-started/kubernetes/installation/hosted/calico.yaml
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 10750 100 10750 0 0 2738 0 0:00:03 0:00:03 --:--:-- 2738
Reivew the Specs, and make changes if neccessary
root@master:~# vim calico.yaml
root@master:~# kubectl apply -f calico.yaml
configmap "calico-config" created
secret "calico-etcd-secrets" created
daemonset "calico-node" created
deployment "calico-policy-controller" created
serviceaccount "calico-policy-controller" created
serviceaccount "calico-node" created
Install Dashboard:
curl -sSL https://rawgit.com/kubernetes/dashboard/master/src/deploy/kubernetes-dashboard.yaml|kubectl apply -f -
for cluster dashboard to appear as part of "kubectl cluster-info"
kubectl label svc kubernetes-dashboard -n kube-system kubernetes.io/cluster-service=true kubernetes.io/name=k8s-dashboard
service "kubernetes-dashboard" labeled
wal@Bei:$ kubectl cluster-info
Kubernetes master is running at https://kubernetes.default.svc.cluster.local:6443
KubeDNS is running at https://kubernetes.default.svc.cluster.local:6443/api/v1/namespaces/kube-system/services/kube-dns/proxy
k8s-dashboard is running at https://kubernetes.default.svc.cluster.local:6443/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
Install heapster for monitoring as well HPA Horizontal Pod Autoscaling.
git clone https://github.com/kubernetes/heapster
cd heapster
kubectl create -f deploy/kube-config/influxdb/
kubectl create -f deploy/kube-config/rbac/heapster-rbac.yaml
kubectl cluster-info
kubectl get pods -n kube-system
wal@Bei:~$ kubectl get svc -n kube-system
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
heapster 10.104.218.87 <none> 80/TCP 13m
kube-dns 10.96.0.10 <none> 53/UDP,53/TCP 20h
kubernetes-dashboard 10.102.206.76 <none> 80/TCP 19h
monitoring-grafana 10.110.8.226 <none> 80/TCP 13m
monitoring-influxdb 10.103.243.167 <none> 8086/TCP 13m
kubectl top node
kubectl top pod --all-namespaces
wal@Bei:~/code/gitrepos/docker-k8s-lab/lab/k8s/multi-node/vagrant/kunr$ kubectl cluster-info
Kubernetes master is running at https://kubernetes.default.svc.cluster.local:6443
KubeDNS is running at https://kubernetes.default.svc.cluster.local:6443/api/v1/namespaces/kube-system/services/kube-dns/proxy
k8s-dashboard is running at https://kubernetes.default.svc.cluster.local:6443/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
Cluster Health
etcd:
root@master:~# /var/lib/docker/aufs/mnt/2975200ced98f0d9efa74e9cdff0c416589e0e41883c0b1685ee42f369ae8b39/usr/local/bin/etcdctl cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://127.0.0.1:2379
cluster is healthy
Nodes
Pods
Components:
from Master host:
root@master:~# kubectl get componentstatus
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-0 Healthy {"health": "true"}
from worker node:
Test application End to End testing:
create project "namespace"
kubectl create ns chapter7
kubectl run alpaca-prod --image=gcr.io/kuar-demo/kuard-amd64:1 --replicas=3 --port=8080 --labels="ver=1,app=alpaca,env=prod" -n chapter7
kubectl run bandicoot-prod--image=gcr.io/kuar-demo/kuard-amd64:2 --replicas=2 --port=8080 --labels="ver=2,app=bandicoot,env=prod" -n chapter7
kubectl expose deployment bandicot-prod -n chapter7
kubectl expose deployment bandicoot-prod -n chapter7
kubectl get all -n chapter7
kubectl expose deployment bandicoot-prod --type NodePort -n chapter7
kubectl expose deployment alpaca-prod --type NodePort -n chapter7
Delete project "namespace"
Troubleshooting:
CNI network
Flannel:
Calico:
Delete cluster nodes:
kubectl drain --force --ignore-daemonsets --delete-local-data worker1
kubectl drain --force --ignore-daemonsets --delete-local-data worker2
then run kubectl reset on each node (worker1, and worker2)
root@worker1:~# kubeadm reset
[preflight] Running pre-flight checks
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
[reset] Removing kubernetes-managed containers
[reset] No etcd manifest found in "/etc/kubernetes/manifests/etcd.yaml", assuming external etcd.
[reset] Deleting contents of stateful directories: [/var/lib/kubelet /etc/cni/net.d /var/lib/dockershim]
[reset] Deleting contents of config directories: [/etc/kubernetes/manifests /etc/kubernetes/pki]
[reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf]
root@worker2:~# kubeadm reset
[preflight] Running pre-flight checks
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
[reset] Removing kubernetes-managed containers
[reset] No etcd manifest found in "/etc/kubernetes/manifests/etcd.yaml", assuming external etcd.
[reset] Deleting contents of stateful directories: [/var/lib/kubelet /etc/cni/net.d /var/lib/dockershim]
[reset] Deleting contents of config directories: [/etc/kubernetes/manifests /etc/kubernetes/pki]
[reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf]
Manual Scheduling of pod:
if you require a pod to start on a specific node, you can specify this in POD spec.nodeName, that is what DaemonSets do.
apiVersion: v1
kind: Pod
metadata:
labels:
app: kuard
version: "2"
name: kuard-manual
namespace: default
spec:
nodeName: worker2
containers:
- image: gcr.io/kuar-demo/kuard-amd64:2
imagePullPolicy: IfNotPresent
name: kuard
dnsPolicy: ClusterFirst
restartPolicy: Always