■ 목적
MASTER1대 + NODE 3대의 쿠버네티스 클러스터 구축
 

 

■ OS설치
대상: master 1대 + node 3대
Linux 계열 OS 설치
 
 
■ OS 기본 환경 구성
대상: master 1대 + node 3대

 

[yum 최신 업데이트 및 추가 유틸리티 설치]
yum -y update
yum install -y yum-utils  device-mapper-persistent-data   lvm2 net-tools

 

[SWAP 설정 Off, 방화벽 Off, SELINUX Disabled 적용]
swapoff -a && sed -i '/swap/s/^/#/' /etc/fstab
systemctl stop firewalld && systemctl disable firewalld
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
 
■ hosts파일 수정
대상: master 1대 + node 3대
/etc/hosts에 아래와 같이 설정 추가 (IP는 본인 서버 설정에 맞게 적용)
 
192.168.114.128 master1
192.168.114.131 node1
192.168.114.129 node12
192.168.114.130 node13
 
■ Docker 설치
대상: master 1대 + node 3대
 
yum-config-manager    --add-repo     https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce docker-ce-cli containerd.io -y
 
■ Docker 기동
대상: master 1대 + node 3대
systemctl start docker && systemctl enable docker
 
■ Kubernetes 기본 환경 구성
대상: master 1대 + node 3대
 
[SWAP 설정 Off, 방화벽 Off, SELINUX Disabled 적용]
swapoff -a && sed -i '/swap/s/^/#/' /etc/fstab
systemctl stop firewalld && systemctl disable firewalld
 
 
[네트워크 관련 OS Kenel Tuning]
cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
 
 
[K8S관련 yum Repository 추가]
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
enabled=1
gpgcheck=1
repo_gpgcheck=1
EOF
 
[K8S 패키지 설치]
yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
systemctl enable --now kubelet && systemctl start kubelet
 
■ Master 서버 생성
대상: master 1대
kubeadm init --pod-network-cidr 10.244.0.0/16
--pod-network-cidr=10.244.0.0/16 은 Flannel 에서 사용하는 설정이며 변경 가능.
 
아래 붉은색으로 표시된 부분은 반드시 별도 저장해 둘것
 
# kubeadm init --pod-network-cidr 10.244.0.0/16
[init] using Kubernetes version: v1.11.2
[preflight] running pre-flight checks
I0903 19:18:37.032588   86064 kernel_validator.go:81] Validating kernel version
I0903 19:18:37.032757   86064 kernel_validator.go:96] Validating kernel config
[preflight/images] Pulling images required for setting up a Kubernetes cluster
[preflight/images] This might take a minute or two, depending on the speed of yo                                           ur internet connection
[preflight/images] You can also perform this action in beforehand using 'kubeadm                                            config images pull'
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/                                           kubeadm-flags.env"
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[preflight] Activating the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [test-k8s-master-n                                           cl kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.c                                           luster.local] and IPs [10.96.0.1 10.106.234.130]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Generated etcd/ca certificate and key.
[certificates] Generated etcd/server certificate and key.
[certificates] etcd/server serving cert is signed for DNS names [test-k8s-master                                           -ncl localhost] and IPs [127.0.0.1 ::1]
[certificates] Generated etcd/peer certificate and key.
[certificates] etcd/peer serving cert is signed for DNS names [test-k8s-master-n                                           cl localhost] and IPs [10.106.234.130 127.0.0.1 ::1]
[certificates] Generated etcd/healthcheck-client certificate and key.
[certificates] Generated apiserver-etcd-client certificate and key.
[certificates] valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.                                           conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[controlplane] wrote Static Pod manifest for component kube-apiserver to "/etc/k                                           ubernetes/manifests/kube-apiserver.yaml"
[controlplane] wrote Static Pod manifest for component kube-controller-manager t                                           o "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] wrote Static Pod manifest for component kube-scheduler to "/etc/k                                           ubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/m                                           anifests/etcd.yaml"
[init] waiting for the kubelet to boot up the control plane as Static Pods from                                            directory "/etc/kubernetes/manifests"
[init] this might take a minute or longer if the control plane images have to be                                            pulled
[apiclient] All control plane components are healthy after 40.501916 seconds
[uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in t                                           he "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.11" in namespace kube-system wi                                           th the configuration for the kubelets in the cluster
[markmaster] Marking the node test-k8s-master-ncl as master by adding the label                                            "node-role.kubernetes.io/master=''"
[markmaster] Marking the node test-k8s-master-ncl as master by adding the taints                                            [node-role.kubernetes.io/master:NoSchedule]
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to t                                           he Node API object "test-k8s-master-ncl" as an annotation
[bootstraptoken] using token: pvpoff.3gi89fsxl6q6vq21
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CS                                           Rs in order for nodes to get long term certificate credentials
[bootstraptoken] configured RBAC rules to allow the csrapprover controller autom                                           atically approve CSRs from a Node Bootstrap Token
[bootstraptoken] configured RBAC rules to allow certificate rotation for all nod                                           e client certificates in the cluster
[bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public" name                                           space
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
 
Your Kubernetes master has initialized successfully!
 
To start using your cluster, you need to run the following as a regular user:
 
  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config
 
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
 
You can now join any number of machines by running the following on each node
as root:
 
  kubeadm join 192.168.114.128:6443 --token pvpoff.3gi19fsxl8q6vq47 --discovery-t                                           oken-ca-cert-hash sha256:e57e547d3697386005324524878f42b670db3f83227ff247464f470                                           f2fddf2d6
 
 
 
■ Flannel Network 설치
대상: master 1대
 
 
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.extensions/kube-flannel-ds created
 

 

■ Kubectl 명령어 환경 설정 구성
대상: master 1대 및 필요한 서버
 
kubectl 클라이언트로 사용할 계정 환경 구성.
아까 master서버에서 별도 기록한 설정을 복사한다.
$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
 

 

■ Node 서버 구성
대상:Node 서버 3대
 
아까 master 서버에서 별도 기록한 kubeadm join 명령을 수행하여 클러스터에 join 한다.
$ sudo kubeadm join 192.168.114.128:6443 --token pvpoff.3gi19fsxl8q6vq47 --discovery-token-ca-cert-hash sha256:e57e547d3697386005324524878f42b670db3f83227ff247464f4702fddf2d6
 
 
■ 점검
 
kubectl get node명령을 통해 모든 node가 READY 상태인지 확인한다.
ku# kubectl get nodes
NAME                    STATUS    ROLES     AGE       VERSION
k8s-master-ncl     Ready     master    19m       v1.11.2
kube-node001-ncl   Ready     <none>    1m        v1.11.2
kube-node002-ncl   Ready     <none>    1m        v1.11.2
kube-node003-ncl   Ready     <none>    1m        v1.11.2
 
 
 

 

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Ingress에 Sticky Session 적용하기  (0) 2020.03.27

■ 개요:
WAS에서 로그인 로직이 존재하는 경우, Ingress에서 Multi POD를 구성하면 로그인이 끊긴다.


■ 원인:
Ingress는 기본적으로 Round-Robin으로 사용자 접속 정보를 Routing하므로, 사용자 세션 정보가 없는 POD로도 지속적으로 사용자 Request를 보낸다.

따라서 Session 정보가 없는 POD에 의한 처리가 될 경우 세션이 끊긴다.


■ 해결책:
두가지 방안이 있다.

  1. Redis와 같은 Session Manager를 구성하여 Session Replication 하기
  2. Ingress에서 Sticky Session을 적용해서 Ingress Routing을 고정하기.
  
여기서는 Ingress에 Sticky Session을 적용하는 법을 가이드한다.


■ Ingress에 ticky session 적용 절차

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: nginx-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    kubernetes.io/ingress.class: "nginx"
    nginx.ingress.kubernetes.io/affinity: "cookie"
    nginx.ingress.kubernetes.io/session-cookie-hash: "sha1"
    nginx.ingress.kubernetes.io/session-cookie-name: "route"
spec:
  rules:
  - host: test.skcc.com
    http:
      paths:
      - path: /
        backend:
          serviceName: svc-weblogic12c
          servicePort: 17001


 

 

 

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