美文网首页
RKE 构建高可用的 Kubernetes 集群

RKE 构建高可用的 Kubernetes 集群

作者: 不安分的情绪 | 来源:发表于2022-05-27 09:13 被阅读0次

    RKE 概述

    Rancher Kubernetes Engine (RKE) 是一个 CNCF 认证的 Kubernetes 发行版,完全在 Docker 容器中运行。它适用于裸机和虚拟化服务器。RKE 解决了安装复杂的问题,这是 Kubernetes 社区的一个常见问题。使用 RKE,Kubernetes 的安装和操作既简单又容易自动化,并且完全独立于您运行的操作系统和平台。只要你能运行受支持的 Docker 版本,你就可以使用 RKE 部署和运行 Kubernetes。

    Kubernetes 集群环境介绍

    本次使用 CentOS7.9 最小化安装,集群机器规划信息如下表,软件版本信息如下:

    • rke: v1.3.11
    • kubernetes: v1.23.6
    • docker: 20.10.0
    主机名 IP 地址 机器配置 用途
    rke-lb 192.168.56.101 1C1G Nginx
    rke-master-1 192.168.56.111 4C4G controlplane,etcd,worker
    rke-master-2 192.168.56.112 4C4G controlplane,etcd,worker
    rke-master-3 192.168.56.113 4C4G controlplane,etcd,worker
    rke-worker-1 192.168.56.211 4C4G worker
    rke-worker-1 192.168.56.212 4C4G worker

    机器环境设置

    • 主机名解析
    ~]$ sudo cat /etc/hosts
    192.168.56.101  rke-lb   rancher-ui.linux.io
    192.168.56.111  rke-master-1
    192.168.56.112  rke-master-2
    192.168.56.113  rke-master-3
    192.168.56.211  rke-worker-1
    192.168.56.212  rke-worker-2
    
    • 安装基础软件包
    {
     sudo yum remove -y  firewalld python-firewall firewalld-filesystem
     sudo yum install -y bash-completion conntrack-tools ipset ipvsadm libseccomp nfs-utils psmisc socat wget vim net-tools ntpdate
    }
    
    • 时间同步
    {
    echo '*/5 * * * * /usr/sbin/ntpdate ntp.aliyun.com &> /dev/null' |sudo tee /var/spool/cron//root
    }
    
    • 关闭Selinux、Firewalld 已以及 Swap 分区
    {
    sudo setenforce 0
    sudo sed -i 's@SELINUX=enforcing@SELINUX=disabled@' /etc/selinux/config
    sudo swapoff -a && sysctl -w vm.swappiness=0
    sudo sed -i '/swap/d' /etc/fstab
    sudo systemctl stop firewalld && sudo systemctl disable firewalld
    }
    
    • 加载内核模块
    {
    for i in br_netfilter ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh nf_conntrack;do
        sudo modprobe $i
    done
    sudo modprobe nf_conntrack_ipv4 || echo "NoFound"
    sudo echo 'br_netfilter
    ip_vs
    ip_vs_rr
    ip_vs_wrr
    ip_vs_sh
    nf_conntrack
    nf_conntrack_ipv4'|sudo tee  /etc/modules-load.d/10-k8s-modules.conf
    sudo systemctl  enable systemd-modules-load --now
    }
    
    • 修改/添加内核参数
    {
    sudo echo 'net.ipv4.ip_forward = 1
    net.bridge.bridge-nf-call-iptables = 1
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-arptables = 1
    # KERNEL_VER < 4.12
    #net.ipv4.tcp_tw_recycle = 0
    #net.ipv4.tcp_tw_reuse = 0
    net.core.somaxconn = 32768
    net.netfilter.nf_conntrack_max=1000000
    vm.swappiness = 0
    vm.max_map_count=655360
    fs.file-max=6553600
    # PROXY_MODE == "ipvs"
    net.ipv4.tcp_keepalive_time = 600
    net.ipv4.tcp_keepalive_intvl = 30
    net.ipv4.tcp_keepalive_probes = 10'|sudo tee -a /etc/sysctl.d/95-k8s-sysctl.conf
    sudo sysctl -p /etc/sysctl.d/95-k8s-sysctl.conf
    }
    # 禁用sctp
    {
    sudo echo '# put sctp into blacklist
    install sctp /bin/true'|sudo tee /etc/modprobe.d/sctp.conf
    }
    
    • 修改 ulimits 参数

    {
    sudo mkdir -pv /etc/systemd/system.conf.d/
    echo '[Manager]
    DefaultLimitCORE=infinity
    DefaultLimitNOFILE=100000
    DefaultLimitNPROC=100000'|sudo tee /etc/systemd/system.conf.d/30-k8s-ulimits.conf
    }
    

    安装容器运行时

    {
    sudo yum install -y yum-utils device-mapper-persistent-data lvm2
    sudo yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
    sudo sed -i 's+download.docker.com+mirrors.aliyun.com/docker-ce+' /etc/yum.repos.d/docker-ce.repo
    sudo yum makecache fast
    sudo yum -y install docker-ce-20.10.0
    }
    
    {
    sudo mkdir /etc/docker  && sudo mkdir -pv /data/docker-root
    echo '{
        "oom-score-adjust": -1000,
        "log-driver": "json-file",
        "log-opts": {
        "max-size": "100m",
        "max-file": "3"
        },
        "max-concurrent-downloads": 10,
        "max-concurrent-uploads": 10,
        "bip": "172.20.1.0/16",
        "storage-driver": "overlay2",
        "storage-opts": [
        "overlay2.override_kernel_check=true"
        ],
        "registry-mirrors": ["https://o4uba187.mirror.aliyuncs.com"],
        "data-root":  "/data/docker-root",
        "exec-opts": ["native.cgroupdriver=systemd"]
    }'|sudo tee /etc/docker/daemon.json
    sudo systemctl enable docker --now
    }
    

    安装 kubernetes 集群

    • 创建普通用户
    {
    useradd vagrant
    echo "vagrant"|passwd --stdin vagrant
    echo "vagrant  ALL=(ALL)       NOPASSWD: ALL" >> /etc/sudoers.d/vagrant
    }
    
    {
    sudo usermod -aG docker vagrant
    sudo chown  vagrant.vagrant /var/run/docker.sock
    }
    
    • 主机互信
    sudo yum install -y sshpass
    cat ssh-copy.sh
    #!/bin/bash
    #
    IP="192.168.56.111
    192.168.56.112
    192.168.56.113
    192.168.56.211
    192.168.56.212"
    
    #ssh-keygen -t rsa -b 2048 -N '' -f ~/.ssh/id_rsa
    
    for node in ${IP};do
        sshpass -p vagrant ssh-copy-id  ${node}  -o StrictHostKeyChecking=no
        ssh $node "sudo chown vagrant.vagrant /var/run/docker.sock "
        if [ $? -eq 0 ];then
            echo -e "\033[46;31m ${node} 秘钥copy成功 \033[0m"
        else
            echo -e "\033[43;31m ${node} 秘钥copy失败 \033[0m"
        fi
    done
    
    bash ssh-copy.sh
    
    • 安装 rke
    {
    sudo wget https://rancher-mirror.rancher.cn/rke/v1.3.11/rke_linux-amd64  -o /usr/local/bin/rke
    sudo chown vagrant.vagrant  /usr/local/bin/rke && chmod +x /usr/local/bin/rke
    }
    
    • 初始化集群
    ]$ rke config
    [+] Cluster Level SSH Private Key Path [~/.ssh/id_rsa]:
    [+] Number of Hosts [1]: 5
    [+] SSH Address of host (1) [none]: 192.168.56.111
    [+] SSH Port of host (1) [22]:
    [+] SSH Private Key Path of host (192.168.56.111) [none]:
    [-] You have entered empty SSH key path, trying fetch from SSH key parameter
    [+] SSH Private Key of host (192.168.56.111) [none]:
    [-] You have entered empty SSH key, defaulting to cluster level SSH key: ~/.ssh/id_rsa
    [+] SSH User of host (192.168.56.111) [ubuntu]: vagrant
    [+] Is host (192.168.56.111) a Control Plane host (y/n)? [y]: y
    [+] Is host (192.168.56.111) a Worker host (y/n)? [n]: y
    [+] Is host (192.168.56.111) an etcd host (y/n)? [n]: y
    [+] Override Hostname of host (192.168.56.111) [none]: rke-master-1
    [+] Internal IP of host (192.168.56.111) [none]: 192.168.56.111
    [+] Docker socket path on host (192.168.56.111) [/var/run/docker.sock]:
    [+] SSH Address of host (2) [none]:
    ...
    [+] Docker socket path on host (192.168.56.212) [/var/run/docker.sock]:
    [+] Network Plugin Type (flannel, calico, weave, canal, aci) [canal]: canel
    [+] Authentication Strategy [x509]:
    [+] Authorization Mode (rbac, none) [rbac]:
    [+] Kubernetes Docker image [rancher/hyperkube:v1.23.6-rancher1]: registry.cn-hangzhou.aliyuncs.com/rancher/hyperkube:v1.23.6-rancher1
    [+] Cluster domain [cluster.local]:
    [+] Service Cluster IP Range [10.43.0.0/16]:
    [+] Enable PodSecurityPolicy [n]:
    [+] Cluster Network CIDR [10.42.0.0/16]:
    [+] Cluster DNS Service IP [10.43.0.10]:
    [+] Add addon manifest URLs or YAML files [no]:
    
    # 完整配置文件
     cat cluster.yml
    # If you intended to deploy Kubernetes in an air-gapped environment,
    # please consult the documentation on how to configure custom RKE images.
    nodes:
    - address: 192.168.56.111
      port: "22"
      internal_address: 192.168.56.111
      role:
      - controlplane
      - worker
      - etcd
      hostname_override: rke-master-1
      user: vagrant
      docker_socket: /var/run/docker.sock
      ssh_key: ""
      ssh_key_path: ~/.ssh/id_rsa
      ssh_cert: ""
      ssh_cert_path: ""
      labels: {}
      taints: []
    - address: 192.168.56.112
      port: "22"
      internal_address: 192.168.56.112
      role:
      - controlplane
      - worker
      - etcd
      hostname_override: rke-master-2
      user: vagrant
      docker_socket: /var/run/docker.sock
      ssh_key: ""
      ssh_key_path: ~/.ssh/id_rsa
      ssh_cert: ""
      ssh_cert_path: ""
      labels: {}
      taints: []
    - address: 192.168.56.113
      port: "22"
      internal_address: 192.168.56.113
      role:
      - controlplane
      - worker
      - etcd
      hostname_override: rke-master-3
      user: vagrant
      docker_socket: /var/run/docker.sock
      ssh_key: ""
      ssh_key_path: ~/.ssh/id_rsa
      ssh_cert: ""
      ssh_cert_path: ""
      labels: {}
      taints: []
    - address: 192.168.56.211
      port: "22"
      internal_address: 192.168.56.211
      role:
      - worker
      hostname_override: rke-worker-1
      user: vagrant
      docker_socket: /var/run/docker.sock
      ssh_key: ""
      ssh_key_path: ~/.ssh/id_rsa
      ssh_cert: ""
      ssh_cert_path: ""
      labels:
        app: ingress
      taints: []
    - address: 192.168.56.212
      port: "22"
      internal_address: 192.168.56.212
      role:
      - worker
      hostname_override: rke-worker-2
      user: vagrant
      docker_socket: /var/run/docker.sock
      ssh_key: ""
      ssh_key_path: ~/.ssh/id_rsa
      ssh_cert: ""
      ssh_cert_path: ""
      labels: 
        app: ingress
      taints: []
    services:
      etcd:
        image: ""
        # 修改空间配额为$((6*1024*1024*1024)),默认2G,最大8G
        extra_args:
          quota-backend-bytes: "6442450944"
          auto-compaction-retention: 240 #(单位小时)
        extra_binds: []
        extra_env: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
        external_urls: []
        ca_cert: ""
        cert: ""
        key: ""
        path: ""
        uid: 0
        gid: 0
        snapshot: true
        retention: 24h
        creation: 5m0s
        backup_config:
          enabled: true # 设置true启用ETCD自动备份,设置false禁用;
          interval_hours: 12 # 快照创建间隔时间,不加此参数,默认5分钟;
          retention: 6 # etcd备份保留份数
      kube-api:
        image: ""
        extra_args: {}
        extra_binds: []
        extra_env: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
        service_cluster_ip_range: 10.43.0.0/16
        service_node_port_range: ""
        pod_security_policy: false
        always_pull_images: false
        secrets_encryption_config: null
        audit_log: null
        admission_configuration: null
        event_rate_limit: null
      kube-controller:
        image: ""
        extra_args: {}
        extra_binds: []
        extra_env: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
        cluster_cidr: 10.42.0.0/16
        service_cluster_ip_range: 10.43.0.0/16
      scheduler:
        image: ""
        extra_args: {}
        extra_binds: []
        extra_env: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
      kubelet:
        image: ""
        extra_args: {}
        extra_binds: []
        extra_env: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
        cluster_domain: cluster.local
        infra_container_image: ""
        cluster_dns_server: 10.43.0.10
        fail_swap_on: false
        generate_serving_certificate: false
      kubeproxy:
        image: ""
        extra_env: []
        extra_args:
          # 默认使用iptables进行数据转发,如果要启用ipvs,则此处设置为`ipvs`,一并添加下面的`extra_binds`
          proxy-mode: "ipvs"
          # 与kubernetes apiserver通信并发数,默认10;
          kube-api-burst: 20
          # 与kubernetes apiserver通信时使用QPS,默认值5,QPS=并发量/平均响应时间
          kube-api-qps: 10
        extra_binds: []
        win_extra_args: {}
        win_extra_binds: []
        win_extra_env: []
    network:
      plugin: canal
      # 指定网络接口
      options:
        canal_iface: eth1
      mtu: 0
      node_selector: {}
      update_strategy: null
      tolerations: []
    authentication:
      strategy: x509
      sans: []
      webhook: null
    addons: ""
    addons_include: []
    system_images:
      etcd: rancher/mirrored-coreos-etcd:v3.5.3
      alpine: rancher/rke-tools:v0.1.80
      nginx_proxy: rancher/rke-tools:v0.1.80
      cert_downloader: rancher/rke-tools:v0.1.80
      kubernetes_services_sidecar: rancher/rke-tools:v0.1.80
      kubedns: rancher/mirrored-k8s-dns-node-cache:1.21.1
      dnsmasq: rancher/mirrored-k8s-dns-dnsmasq-nanny:1.21.1
      kubedns_sidecar: rancher/mirrored-k8s-dns-sidecar:1.21.1
      kubedns_autoscaler: rancher/mirrored-cluster-proportional-autoscaler:1.8.5
      coredns: rancher/mirrored-coredns-coredns:1.9.0
      coredns_autoscaler: rancher/mirrored-cluster-proportional-autoscaler:1.8.5
      nodelocal: rancher/mirrored-k8s-dns-node-cache:1.21.1
      kubernetes: registry.cn-hangzhou.aliyuncs.com/rancher/hyperkube:v1.23.6-rancher1
      flannel: rancher/mirrored-coreos-flannel:v0.15.1
      flannel_cni: rancher/flannel-cni:v0.3.0-rancher6
      calico_node: rancher/mirrored-calico-node:v3.22.0
      calico_cni: rancher/mirrored-calico-cni:v3.22.0
      calico_controllers: rancher/mirrored-calico-kube-controllers:v3.22.0
      calico_ctl: rancher/mirrored-calico-ctl:v3.22.0
      calico_flexvol: rancher/mirrored-calico-pod2daemon-flexvol:v3.22.0
      canal_node: rancher/mirrored-calico-node:v3.22.0
      canal_cni: rancher/mirrored-calico-cni:v3.22.0
      canal_controllers: rancher/mirrored-calico-kube-controllers:v3.22.0
      canal_flannel: rancher/mirrored-flannelcni-flannel:v0.17.0
      canal_flexvol: rancher/mirrored-calico-pod2daemon-flexvol:v3.22.0
      weave_node: weaveworks/weave-kube:2.8.1
      weave_cni: weaveworks/weave-npc:2.8.1
      pod_infra_container: rancher/mirrored-pause:3.6
      ingress: rancher/nginx-ingress-controller:nginx-1.2.0-rancher1
      ingress_backend: rancher/mirrored-nginx-ingress-controller-defaultbackend:1.5-rancher1
      ingress_webhook: rancher/mirrored-ingress-nginx-kube-webhook-certgen:v1.1.1
      metrics_server: rancher/mirrored-metrics-server:v0.6.1
      windows_pod_infra_container: rancher/mirrored-pause:3.6
      aci_cni_deploy_container: noiro/cnideploy:5.1.1.0.1ae238a
      aci_host_container: noiro/aci-containers-host:5.1.1.0.1ae238a
      aci_opflex_container: noiro/opflex:5.1.1.0.1ae238a
      aci_mcast_container: noiro/opflex:5.1.1.0.1ae238a
      aci_ovs_container: noiro/openvswitch:5.1.1.0.1ae238a
      aci_controller_container: noiro/aci-containers-controller:5.1.1.0.1ae238a
      aci_gbp_server_container: noiro/gbp-server:5.1.1.0.1ae238a
      aci_opflex_server_container: noiro/opflex-server:5.1.1.0.1ae238a
    ssh_key_path: ~/.ssh/id_rsa
    ssh_cert_path: ""
    ssh_agent_auth: false
    authorization:
      mode: rbac
      options: {}
    ignore_docker_version: null
    enable_cri_dockerd: null
    kubernetes_version: ""
    private_registries: []
    ingress:
      provider: nginx
      network_mode: hostNetwork
      use-forwarded-headers: 'true'
      node_selector:
        app: ingress
      options: {}
      node_selector: {}
      extra_args: {}
      dns_policy: ""
      extra_envs: []
      extra_volumes: []
      extra_volume_mounts: []
      update_strategy: null
      http_port: 0
      https_port: 0
      network_mode: ""
      tolerations: []
      default_backend: null
      default_http_backend_priority_class_name: ""
      nginx_ingress_controller_priority_class_name: ""
      default_ingress_class: null
    cluster_name: ""
    cloud_provider:
      name: ""
    prefix_path: ""
    win_prefix_path: ""
    addon_job_timeout: 0
    bastion_host:
      address: ""
      port: ""
      user: ""
      ssh_key: ""
      ssh_key_path: ""
      ssh_cert: ""
      ssh_cert_path: ""
      ignore_proxy_env_vars: false
    monitoring:
      provider: ""
      options: {}
      node_selector: {}
      update_strategy: null
      replicas: null
      tolerations: []
      metrics_server_priority_class_name: ""
    restore:
      restore: false
      snapshot_name: ""
    rotate_encryption_key: false
    dns: null
    
    • 启动集群
    rke up --config cluster.yml
    
    • 更新集群
    rke up --update-only --config cluster.yml
    

    验证 kubernete 集群

    • 安装 kubectl 工具
    sudo wget -O /usr/local/bin/kubectl  https://rancher-mirror.rancher.cn/kubectl/v1.23.6/linux-amd64-v1.23.6-kubectl
    sudo chown vagrant.vagrant /usr/local/bin/kubectl
    sudo chmod +x /usr/local/bin/kubectl
    
    • 配置认证文件
    mkdir -pv ~/.kube
    cp kube_config_cluster.yml ~/.kube/config
    
    • 查看资源详情
    
    kubectl  get nodes
    NAME           STATUS   ROLES                      AGE   VERSION
    rke-master-1   Ready    controlplane,etcd,worker   10m   v1.23.6
    rke-master-2   Ready    controlplane,etcd,worker   10m   v1.23.6
    rke-master-3   Ready    controlplane,etcd,worker   10m   v1.23.6
    rke-worker-1   Ready    worker                     10m   v1.23.6
    rke-worker-2   Ready    worker                     10m   v1.23.6
    
    kubectl  get pods -A
    NAMESPACE       NAME                                      READY   STATUS      RESTARTS   AGE
    ingress-nginx   ingress-nginx-admission-create-82prb      0/1     Completed   0          9m37s
    ingress-nginx   ingress-nginx-admission-patch-x6zk5       0/1     Completed   3          9m37s
    ingress-nginx   nginx-ingress-controller-p6z77            1/1     Running     0          9m37s
    ingress-nginx   nginx-ingress-controller-zpdct            1/1     Running     0          9m37s
    kube-system     calico-kube-controllers-fc7fcb565-bt6fp   1/1     Running     0          9m56s
    kube-system     canal-27btn                               2/2     Running     0          9m56s
    kube-system     canal-d6tff                               2/2     Running     0          9m57s
    kube-system     canal-htqtg                               2/2     Running     0          9m56s
    kube-system     canal-tg4wq                               2/2     Running     0          9m56s
    kube-system     canal-zn8gr                               2/2     Running     0          9m56s
    kube-system     coredns-548ff45b67-4d4mv                  1/1     Running     0          8m42s
    kube-system     coredns-548ff45b67-llqkk                  1/1     Running     0          9m47s
    kube-system     coredns-autoscaler-d5944f655-5rrmn        1/1     Running     0          9m47s
    kube-system     metrics-server-5c4895ffbd-ws8mx           1/1     Running     0          9m42s
    kube-system     rke-coredns-addon-deploy-job-rvmp5        0/1     Completed   0          9m49s
    kube-system     rke-ingress-controller-deploy-job-sczs5   0/1     Completed   0          9m39s
    kube-system     rke-metrics-addon-deploy-job-79mth        0/1     Completed   0          9m44s
    kube-system     rke-network-plugin-deploy-job-vwjhc       0/1     Completed   0          9m59s
    
    • 部署应用
    kubectl create deployment myapp --image=ikubernetes/myapp:v1 --replicas=3
    kubectl  expose deployment myapp --port=80 --target-port=80 --type=ClusterIP
    
    ~]$ kubectl  get all   -o wide
    NAME                        READY   STATUS    RESTARTS   AGE     IP          NODE           NOMINATED NODE   READINESS GATES
    pod/myapp-9cbc4cf76-6g7gz   1/1     Running   0          2m26s   10.42.0.2   rke-master-3   <none>           <none>
    pod/myapp-9cbc4cf76-b4vtp   1/1     Running   0          2m26s   10.42.1.3   rke-master-2   <none>           <none>
    pod/myapp-9cbc4cf76-cp85t   1/1     Running   0          2m26s   10.42.2.3   rke-master-1   <none>           <none>
    
    NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE    SELECTOR
    service/kubernetes   ClusterIP   10.43.0.1       <none>        443/TCP   16m    <none>
    service/myapp        ClusterIP   10.43.222.216   <none>        80/TCP    103s   app=myapp
    
    NAME                    READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES                 SELECTOR
    deployment.apps/myapp   3/3     3            3           2m26s   myapp        ikubernetes/myapp:v1   app=myapp
    
    NAME                              DESIRED   CURRENT   READY   AGE     CONTAINERS   IMAGES                 SELECTOR
    replicaset.apps/myapp-9cbc4cf76   3         3         3       2m26s   myapp        ikubernetes/myapp:v1   app=myapp,pod-template-hash=9cbc4cf76
    
    [vagrant@rke-master-1 ~]$  curl 10.42.0.2
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    [vagrant@rke-master-1 ~]$ curl 10.42.1.3
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    [vagrant@rke-master-1 ~]$ curl 10.42.2.3
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    [vagrant@rke-master-1 ~]$ curl 10.43.222.216
    Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
    
    ~]$ kubectl  exec -it pod/myapp-9cbc4cf76-6g7gz -- nslookup myapp
    nslookup: can't resolve '(null)': Name does not resolve
    
    Name:      myapp
    Address 1: 10.43.222.216 myapp.default.svc.cluster.local
    

    参考

    相关文章

      网友评论

          本文标题:RKE 构建高可用的 Kubernetes 集群

          本文链接:https://www.haomeiwen.com/subject/zfliprtx.html