Clever Geek Handbook

Configuring a failover Kubernetes cluster on servers with a public and private network using Kubeadm

This article was written because I would like to have such an article in front of my eyes when I deployed the cluster using the documentation. I want to say right away that I am not an expert in K8S, but I had experience with deploying product installations of DC / OS (an ecosystem based on Apache Mesos). For a long time, K8S scared me off by the fact that when you try to study it, you are bombarded with a bunch of concepts and terms, which makes your brain explode.





However, I had a task to configure a failover Bare Metal cluster for a complex application, which is why this article arose. During the tutorial, I will touch on the following aspects:





  • correct installation of K8S using kubeadm on nodes with multiple NICs;





  • implementation of a fault-tolerant Control Plane with shared IP and DNS name access;





  • implementation of an Ingress controller based on Nginx on dedicated nodes with access from the public network;





  • forwarding the K8S API to the public network;





  • access to the K8S Dashboard UI from the administrator's computer.





I installed in Ubuntu 18.04 environment, and therefore some of the steps may not work in your distribution, plus I have specific problems with Keepalived, Pacemaker. The text may contain the phrases "as I understand ..." and "I still do not quite understand ...".





First, let's look at the node topology of the cluster in which we will be deploying K8S. This is a simplified topology with no unnecessary details.





A distinctive feature in my cluster is that all nodes have two network interfaces - on eth0 there is always a public address, and on eth1



- an address from the network 10.120.0.0/16



.





, K8S , NIC. - .









, K8S NIC , , "" , , .









Kubeadm , IP- - , , "-", , .





Enterprise K8S, - , , , Ceph VLAN-.





, Ansible, playbook-, . , .





DNS-

DNS- IP-, . , gw-1



, gw-2



pdns-recursor .





pdns-recursor gw-1



, gw-2



:





allow-from=10.120.0.0/8, 127.0.0.0/8
etc-hosts-file=/etc/hosts.resolv
export-etc-hosts=on
export-etc-hosts-search-suffix=cluster

/etc/hosts.resolv



ansible :





# Ansible managed

10.120.29.231  gw-1 gw-1
10.120.28.23  gw-2 gw-2
10.120.29.32  video-accessors-1 video-accessors-1
10.120.29.226  video-accessors-2 video-accessors-2
10.120.29.153  mongo-1 mongo-1
10.120.29.210  mongo-2 mongo-2
10.120.29.220  mongo-3 mongo-3
10.120.28.172  compute-1 compute-1
10.120.28.26  compute-2 compute-2
10.120.29.70  compute-3 compute-3
10.120.28.127  zk-1 zk-1
10.120.29.110  zk-2 zk-2
10.120.29.245  zk-3 zk-3
10.120.28.21  minio-1 minio-1
10.120.28.25  minio-2 minio-2
10.120.28.158  minio-3 minio-3
10.120.28.122  minio-4 minio-4
10.120.29.187  k8s-1 k8s-1
10.120.28.37  k8s-2 k8s-2
10.120.29.204  k8s-3 k8s-3
10.120.29.135  kafka-1 kafka-1
10.120.29.144  kafka-2 kafka-2
10.120.28.130  kafka-3 kafka-3
10.120.29.194  clickhouse-1 clickhouse-1
10.120.28.66  clickhouse-2 clickhouse-2
10.120.28.61  clickhouse-3 clickhouse-3
10.120.29.244  app-1 app-1
10.120.29.228  app-2 app-2
10.120.29.33  prometeus prometeus
10.120.29.222  manager manager

10.120.29.187 k8s-cp
Ansible 
# {{ ansible_managed }}

{% for item in groups['all'] %}
{% set short_name = item.split('.') %}
{{ hostvars[item]['host'] }}  {{ item }} {{ short_name[0] }}
{% endfor %}

10.120.0.1 k8s-cp





, DNS-, DHCP, DNS-. Ubuntu 18.04 systemd-resolved



, gw-1, gw-2



. systemd, systemd-resolved



, /etc/systemd/network/0-eth0.network



:





[Match]
Name=eth0

[Network]
DHCP=ipv4
DNS=10.120.28.23 10.120.29.231
Domains=cluster

[DHCP]
UseDNS=false
UseDomains=false

: DHCP, eth0 DNS- , DHCP-. 10.120.28.23, 10.120.29.231



*.cluster



.





, systemd-resolved



DHCP. , .





systemd-resolve --status



:





Global
          DNSSEC NTA: 10.in-addr.arpa
                      16.172.in-addr.arpa
                      168.192.in-addr.arpa
                      17.172.in-addr.arpa
                      18.172.in-addr.arpa
                      19.172.in-addr.arpa
                      20.172.in-addr.arpa
                      21.172.in-addr.arpa
                      22.172.in-addr.arpa
                      23.172.in-addr.arpa
                      24.172.in-addr.arpa
                      25.172.in-addr.arpa
                      26.172.in-addr.arpa
                      27.172.in-addr.arpa
                      28.172.in-addr.arpa
                      29.172.in-addr.arpa
                      30.172.in-addr.arpa
                      31.172.in-addr.arpa
                      corp
                      d.f.ip6.arpa
                      home
                      internal
                      intranet
                      lan
                      local
                      private
                      test

Link 3 (eth1)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 2 (eth0)
      Current Scopes: DNS
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 10.120.28.23
                      10.120.29.231
          DNS Domain: cluster

. ping gw-1



, ping gw-1.cluster



ip-.





. Kubernetes . :





sudo -- sh -c "swapoff -a && sed -i '/ swap / s/^/#/' /etc/fstab"

swap- fdisk



.





. Flannel - K8S. , VXLAN



. .





, multicast



, VXLAN



multicast



-, . multicast



- , , VXLAN



, VXLAN



BGP . , Kubernetes - . , Flannel VXLAN



multicast. VXLAN+multicast



over VXLAN+multicast



over Ethernet



, VXLAN-



, Ethernet



multicast



- .





/etc/modules br_netfilter, overlay



.





modprobe br_netfilter && modprobe overlay



, .





/etc/sysctl.conf



:





net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1

sysctl -p



.





ontainerd

. Kubernetes Containerd (, Docker Containerd), :





sudo apt-get update
sudo apt install containerd
sudo sh -- -c "containerd config default | tee /etc/containerd/config.toml"
sudo service containerd restart

kubeadm, kubelet, kubectl

. K8S:





sudo apt-get update && sudo apt-get install -y apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

Control Plane

, Control Plane K8S - k8s-{1,2,3}



. , :





kubeadm init --pod-network-cidr=10.244.0.0/16 \
      --control-plane-endpoint=k8s-cp \
      --apiserver-advertise-address=10.120.29.187

Flannel --pod-network-cidr=10.244.0.0/16



. POD- K8S .





--control-plane-endpoint string Specify a stable IP address or DNS name for the control plane.





DNS IP, K8S- Control Plane. k8s-cp



, ip- 10.120.0.1



(. , , k8s-cp Control Plane: 10.120.29.187 k8s-cp



).





--api-server-advertise-address



. api-server



, Etcd



, , . , kubeadm



, -, . , Etcd



, Etcd



, . .





, Flannel , , Control Plane ( IP- ).





, , .





, , Kubeadm



K8S . , Control Plane . , :





ps xa  | grep -E '(kube-apiserver|etcd|kube-proxy|kube-controller-manager|kube-scheduler)'





. , kubectl



:





mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

kubectl



, kubectl get pods --all-namespaces



. , :





NAMESPACE              NAME                                         READY   STATUS      RESTARTS   AGE
kube-system            etcd-k8s-1                                   1/1     Running     0          2d23h
kube-system            kube-apiserver-k8s-1                         1/1     Running     0          2d23h
kube-system            kube-controller-manager-k8s-1                1/1     Running     1          2d23h
kube-system            kube-scheduler-k8s-1                         1/1     Running     1          2d23h

, 1 , , RESTARTS



, Running



.





Kubernetes , CNI. CNI - Flannel. :





kubectl apply -f https://github.com/coreos/flannel/raw/master/Documentation/kube-flannel.yml

, kubectl get pods --all-namespaces



, , Flannel RESTARTS . - , Flannel ( POD- Flannel):





kubectl logs -n kube-system kube-flannel-ds-xn2j9

, . Control Plane , :





# ssh k8s-2
sudo kubeadm join k8s-cp:6443 --apiserver-advertise-address=10.120.28.37 --token tfqsms.kiek2vk129tpf0b7 --discovery-token-ca-cert-hash sha256:0c446bfabcd99aae7e650d110f8b9d6058cac432078c4fXXXXX6055b4bd --control-plane

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

# ssh k8s-3
sudo kubeadm join k8s-cp:6443 --apiserver-advertise-address=10.120.29.204 --token tfqsms.kiek2vk129tpf0b7 --discovery-token-ca-cert-hash sha256:0c446bfabcd99aae7e650d110f8b9d6058cac432078c4fXXXXXec6055b4bd --control-plane

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

--token



"", kubeadm token create



, .





Etcd



:





kubectl get pods --all-namespaces | grep etcd
kube-system            etcd-k8s-1                                   1/1     Running     0          2d23h
kube-system            etcd-k8s-2                                   1/1     Running     1          2d22h
kube-system            etcd-k8s-3                                   1/1     Running     1          2d22h

Running, . kubectl get pods --all-namespaces



Control Plane:





NAME                            READY   STATUS    RESTARTS   AGE
coredns-74ff55c5b-h2zjq         1/1     Running   0          2d23h
coredns-74ff55c5b-n6b49         1/1     Running   0          2d23h
etcd-k8s-1                      1/1     Running   0          2d23h
etcd-k8s-2                      1/1     Running   1          2d22h
etcd-k8s-3                      1/1     Running   1          2d22h
kube-apiserver-k8s-1            1/1     Running   0          2d23h
kube-apiserver-k8s-2            1/1     Running   1          2d22h
kube-apiserver-k8s-3            1/1     Running   1          2d22h
kube-controller-manager-k8s-1   1/1     Running   1          2d23h
kube-controller-manager-k8s-2   1/1     Running   1          2d22h
kube-controller-manager-k8s-3   1/1     Running   1          2d22h
kube-flannel-ds-2f6d5           1/1     Running   0          2d3h
kube-flannel-ds-2p5vx           1/1     Running   0          2d3h
kube-flannel-ds-4ng99           1/1     Running   3          2d22h
kube-proxy-22jpt                1/1     Running   0          2d3h
kube-proxy-25rxn                1/1     Running   0          2d23h
kube-proxy-2qp8r                1/1     Running   0          2d3h
kube-scheduler-k8s-1            1/1     Running   1          2d23h
kube-scheduler-k8s-2            1/1     Running   1          2d22h
kube-scheduler-k8s-3            1/1     Running   1          2d22h

IP-, Control Plane.





IP DNS

:





  1. Keepalived;





  2. Pacemaker;





  3. kube-vip.





, . Keepalived



, - -, . , , - Ubuntu 18.04 VXLAN



-, Underlay. Tcpdump



VRRP



-, k8s-{1,2,3}



, IP- 3 , MASTER



-. debug , Keepalived



Pacemaker



. - Corosync



Pacemaker



, :





sudo systemctl enable corosync
sudo systemctl enable pacemaker

, , /etc/rc.local



.





, IP- kube-vip, Kubernetes. , kube-vip Control Plane:





apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  name: kube-vip-cp-k8s-1         #  ,  
  namespace: kube-system
spec:
  nodeName: k8s-1                 #      
  containers:
  - args:
    - start
    env:
    - name: vip_arp
      value: "true"
    - name: vip_interface
      value: eth1
    - name: vip_leaderelection
      value: "true"
    - name: vip_leaseduration
      value: "5"
    - name: vip_renewdeadline
      value: "3"
    - name: vip_retryperiod
      value: "1"
    - name: vip_address
      value: 10.120.0.1          #   IP,   
    image: plndr/kube-vip:0.3.1  #   
    imagePullPolicy: Always
    name: kube-vip-cp
    resources: {}
    securityContext:
      capabilities:
        add:
        - NET_ADMIN
        - SYS_TIME
    volumeMounts:
    - mountPath: /etc/kubernetes/admin.conf
      name: kubeconfig
    - mountPath: /etc/ssl/certs
      name: ca-certs
      readOnly: true
  hostNetwork: true
  volumes:
  - hostPath:
      path: /etc/kubernetes/admin.conf
    name: kubeconfig
  - hostPath:
      path: /etc/ssl/certs
    name: ca-certs
status: {}

Control Plane :





kubectl apply -f cluster_config/vip-{1,2,3}.yml

POD-, , 10.120.0.1



. , kube-vip



IP arping



:





sudo arping 10.120.0.1
ARPING 10.120.0.1
42 bytes from 1e:01:17:00:01:22 (10.120.0.1): index=0 time=319.476 usec
42 bytes from 1e:01:17:00:01:22 (10.120.0.1): index=1 time=306.360 msec
42 bytes from 1e:01:17:00:01:22 (10.120.0.1): index=2 time=349.666 usec

kube-vip? IP, , , , .





, kube-vip Kubernetes - gw-1



, gw-2



/etc/hosts.resolv



k8s-cp



:





10.120.0.1 k8s-cp

pdns-recursor sudo service pdns-recursor restart



, k8s-cp



IP 10.120.0.1



. , kubectl



k8s-cp



.





Control Plane K8S. k8s-{1,2,3}



, , .





Worker-

gw-1



, gw-2



, Nginx Ingress (compute-1



).





:





kubeadm token create --print-join-command 
kubeadm join k8s-cp:6443 --token rn0s5p.y6waq1t6y2y6z9vw     --discovery-token-ca-cert-hash sha256:0c446bfabcd99aae7e650d110f8b9d6058cac432078c4fXXXe22ec6055b4bd

# ssh gw-1
sudo kubeadm join k8s-cp:6443 --token rn0s5p.y6waq1t6y2y6z9vw     --discovery-token-ca-cert-hash sha256:0c446bfabcd99aae7e650d110f8b9d6058cac432078c4fXXXe22ec6055b4bd

# ssh gw-2
...

# ssh compute-1

kubectl get pds --all-namespaces



POD-, kubectl get nodes



:





kubectl get nodes
NAME                STATUS   ROLES                  AGE     VERSION
compute-1           Ready    compute                2d23h   v1.20.2
gw-1                Ready    gateway                2d4h    v1.20.2
gw-2                Ready    gateway                2d4h    v1.20.2
k8s-1               Ready    control-plane,master   2d23h   v1.20.2
k8s-2               Ready    control-plane,master   2d23h   v1.20.2
k8s-3               Ready    control-plane,master   2d23h   v1.20.2

, , . , .





:





kubectl label node gw-1 node-role.kubernetes.io/gateway=true
kubectl label node gw-2 node-role.kubernetes.io/gateway=true
kubectl label node compute-1 node-role.kubernetes.io/compute=true

#    
kubectl label node compute-1 node-role.kubernetes.io/compute-

Ingress

, Nginx Ingress gw-1



, gw-2



. Nginx Ingress, :





  • hostNetwork



    ;





  • Deployment "2";





  • gateway



    .





hostNetwork



. , K8S - , API External IP, . , bare metal External IP :





kubectl get nodes --output wide
NAME                STATUS   ROLES                  AGE     VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION       CONTAINER-RUNTIME
compute-1           Ready    compute                3d      v1.20.2   10.120.28.172   <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3
gw-1                Ready    gateway                2d4h    v1.20.2   10.120.29.231   <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3
gw-2                Ready    gateway                2d4h    v1.20.2   10.120.28.23    <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3
k8s-1               Ready    control-plane,master   3d      v1.20.2   10.120.29.187   <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3
k8s-2               Ready    control-plane,master   2d23h   v1.20.2   10.120.28.37    <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3
k8s-3               Ready    control-plane,master   2d23h   v1.20.2   10.120.29.204   <none>        Ubuntu 18.04.5 LTS   4.15.0-135-generic   containerd://1.3.3

, External IP API, Kubernetes . , .





GitHub, , metallb, . , Nginx Ingress, hostNetworking



, Ingress 0.0.0.0:443



, 0.0.0.0:80



.





, Nginx Ingress :





YAML 
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx

---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
  name: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ''
    resources:
      - configmaps
      - pods
      - secrets
      - endpoints
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingresses/status
    verbs:
      - update
  - apiGroups:
      - networking.k8s.io   # k8s 1.14+
    resources:
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ''
    resources:
      - configmaps
    resourceNames:
      - ingress-controller-leader-nginx
    verbs:
      - get
      - update
  - apiGroups:
      - ''
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ''
    resources:
      - events
    verbs:
      - create
      - patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx
subjects:
  - kind: ServiceAccount
    name: ingress-nginx
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller-admission
  namespace: ingress-nginx
spec:
  type: ClusterIP
  ports:
    - name: https-webhook
      port: 443
      targetPort: webhook
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
    node-role.kubernetes.io/gateway: "true"
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/instance: ingress-nginx
      app.kubernetes.io/component: controller
  revisionHistoryLimit: 10
  minReadySeconds: 0
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/component: controller
        node-role.kubernetes.io/gateway: "true"
    spec:
      hostNetwork: true
      dnsPolicy: ClusterFirst
      containers:
        - name: controller
          image: k8s.gcr.io/ingress-nginx/controller:v0.43.0@sha256:9bba603b99bf25f6d117cf1235b6598c16033ad027b143c90fa5b3cc583c5713
          imagePullPolicy: IfNotPresent
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown
          args:
            - /nginx-ingress-controller
            - --election-id=ingress-controller-leader
            - --ingress-class=nginx
            - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
            - --validating-webhook=:8443
            - --validating-webhook-certificate=/usr/local/certificates/cert
            - --validating-webhook-key=/usr/local/certificates/key
          securityContext:
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            runAsUser: 101
            allowPrivilegeEscalation: true
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: LD_PRELOAD
              value: /usr/local/lib/libmimalloc.so
          livenessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 5
          readinessProbe:
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            timeoutSeconds: 1
            successThreshold: 1
            failureThreshold: 3
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
            - name: webhook
              containerPort: 8443
              protocol: TCP
          volumeMounts:
            - name: webhook-cert
              mountPath: /usr/local/certificates/
              readOnly: true
          resources:
            requests:
              cpu: 100m
              memory: 90Mi
      nodeSelector:
        node-role.kubernetes.io/gateway: "true"
      serviceAccountName: ingress-nginx
      terminationGracePeriodSeconds: 300
      volumes:
        - name: webhook-cert
          secret:
            secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
# before changing this value, check the required kubernetes version
# https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#prerequisites
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  name: ingress-nginx-admission
webhooks:
  - name: validate.nginx.ingress.kubernetes.io
    matchPolicy: Equivalent
    rules:
      - apiGroups:
          - networking.k8s.io
        apiVersions:
          - v1beta1
        operations:
          - CREATE
          - UPDATE
        resources:
          - ingresses
    failurePolicy: Fail
    sideEffects: None
    admissionReviewVersions:
      - v1
      - v1beta1
    clientConfig:
      service:
        namespace: ingress-nginx
        name: ingress-nginx-controller-admission
        path: /networking/v1beta1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
rules:
  - apiGroups:
      - admissionregistration.k8s.io
    resources:
      - validatingwebhookconfigurations
    verbs:
      - get
      - update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
rules:
  - apiGroups:
      - ''
    resources:
      - secrets
    verbs:
      - get
      - create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: ingress-nginx-admission
  annotations:
    helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ingress-nginx-admission
subjects:
  - kind: ServiceAccount
    name: ingress-nginx-admission
    namespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-create
  annotations:
    helm.sh/hook: pre-install,pre-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-create
      labels:
        helm.sh/chart: ingress-nginx-3.21.0
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.43.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: create
          image: docker.io/jettech/kube-webhook-certgen:v1.5.1
          imagePullPolicy: IfNotPresent
          args:
            - create
            - --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc
            - --namespace=$(POD_NAMESPACE)
            - --secret-name=ingress-nginx-admission
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: ingress-nginx-admission-patch
  annotations:
    helm.sh/hook: post-install,post-upgrade
    helm.sh/hook-delete-policy: before-hook-creation,hook-succeeded
  labels:
    helm.sh/chart: ingress-nginx-3.21.0
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.43.0
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: admission-webhook
  namespace: ingress-nginx
spec:
  template:
    metadata:
      name: ingress-nginx-admission-patch
      labels:
        helm.sh/chart: ingress-nginx-3.21.0
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/instance: ingress-nginx
        app.kubernetes.io/version: 0.43.0
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/component: admission-webhook
    spec:
      containers:
        - name: patch
          image: docker.io/jettech/kube-webhook-certgen:v1.5.1
          imagePullPolicy: IfNotPresent
          args:
            - patch
            - --webhook-name=ingress-nginx-admission
            - --namespace=$(POD_NAMESPACE)
            - --patch-mutating=false
            - --secret-name=ingress-nginx-admission
            - --patch-failure-policy=Fail
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
      restartPolicy: OnFailure
      serviceAccountName: ingress-nginx-admission
      securityContext:
        runAsNonRoot: true
        runAsUser: 2000





kubectl apply -f nginx-ingress.yaml



, POD- Nginx, gw-1



, gw-2



443- 80- :





kubectl get pods --all-namespaces | grep nginx
ingress-nginx          ingress-nginx-admission-create-4mm9m         0/1     Completed   0          46h
ingress-nginx          ingress-nginx-admission-patch-7jkwg          0/1     Completed   2          46h
ingress-nginx          ingress-nginx-controller-b966cf6cd-7kpzm     1/1     Running     1          46h
ingress-nginx          ingress-nginx-controller-b966cf6cd-ckl97     1/1     Running     0          46h

gw-1



, gw-2



:





sudo netstat -tnlp | grep -E ':(443|80)'
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      2661/nginx: master  
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      2661/nginx: master  
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      2661/nginx: master  
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      2661/nginx: master  
tcp6       0      0 :::443                  :::*                    LISTEN      2661/nginx: master  
tcp6       0      0 :::443                  :::*                    LISTEN      2661/nginx: master  
tcp6       0      0 :::80                   :::*                    LISTEN      2661/nginx: master  
tcp6       0      0 :::80                   :::*                    LISTEN      2661/nginx: master

gw-1



, gw-2



80- Nginx. , gw-1



, gw-2



DNS, CDN ..





inress , , Ingress ( ) - echo1.yaml



:





apiVersion: v1
kind: Service
metadata:
  name: echo1
spec:
  ports:
  - port: 80
    targetPort: 5678
  selector:
    app: echo1
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: echo1
spec:
  selector:
    matchLabels:
      app: echo1
  replicas: 2
  template:
    metadata:
      labels:
        app: echo1
    spec:
      containers:
      - name: echo1
        image: hashicorp/http-echo
        args:
        - "-text=echo1"
        ports:
        - containerPort: 5678

kubectl apply -f echo1.yaml



. Ingress (ingress-echo1.yaml



):





apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: echo-ingress
spec:
  rules:
  - host: echo1.example.com
    http:
      paths:
      - backend:
          serviceName: echo1
          servicePort: 80

kubectl apply -f ingress-echo1.yaml



. , /etchosts



echo1.example.com



:





127.0.0.1	localhost
127.0.1.1	manager

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

X.Y.Z.C echo1.example.com

Nginx Ingress. curl



:





curl echo1.example.com
echo1

K8S Dashboard

Dashboard :





kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml

Dashboard , , http



, localhost



. , - Dashboard Ingress. , Dashboard RBAC Kubernetes, Dashboard.





. :





cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
EOF

:





cat <<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard
EOF

, Dashboard:





kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"

kubect



$HOME/.kube/config



, "" k8s-cp



, kubectl proxy



Dashboard : http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/.





, , API Kubernetes HAProxy.





API K8S

gw-1



, gw-2



haproxy



. /etc/haproxy/haproxy.cfg



, defaults



:





defaults
    # mode is inherited by sections that follow
    mode tcp

frontend k8s
    # receives traffic from clients
    bind :6443
    default_backend kubernetes

backend kubernetes
    # relays the client messages to servers
    server k8s k8s-cp:6443

API K8S , /etc/hosts



gw-1



gw-2



k8s-cp



. kubectl



, kubectl proxy



:





kubectl proxy
Starting to serve on 127.0.0.1:8001

http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/ Dashboard K8S:





Dasboard, :





kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"
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.ht-RyqLXY4UzBnxIzJcnQn8Kk2iHWZzKVeAjUhKkJ-vOAtyqBu50rExgiRWsEHWfJp1p9xN8sXFKg62FFFbHWftPf6PmwfcBK2lXPy6OL9OaooP17WJVn75KKXIZHPWLO9VmRXPB1S-v2xFuG_J8jHB8pZHJlFjp4zIXfB--QwhrxeoTt5zv3CfXCl1_VYgCoqaxRsa7e892-vtMijBo7EZfJiyuAUQr_TsAIDY3zOWFJeHbwPFWzL_1fF9Y2o3r0pw7hYZHUoI8Z-3hbfOi10QBRyQlNZTMFSh7Z38RRbV1tw2ZmMvgSQyHa9TZFy2kYik6VnugNB2cilamo_b7hg

Dashboard:





As I wrote at the beginning of this article, I already have experience deploying container management systems based on Docker, Apache Mesos (DC / OS). However, the Kubernetes documentation seemed complex, confusing, and fragmentary to me. To get the current result, I went through a lot of third-party tutorials, Issue GitHub and, of course, Kubernetes documentation. Hope this guide will save you some time.







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