Kubernetes前提条件准备

环境条件


  1. 升级内核
  2. 修改内核参数
  3. 配置cgroup
  4. 安装CRI

内核参数


  1. 配置网络流量转发
    cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
    overlay
    br_netfilter
    EOF
 
  1. 启用模块
    modprobe overlay
    modprobe br_netfilter
 
  1. 调整内核参数net.ipv4.ip_forward
    cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
    net.bridge.bridge-nf-call-iptables = 1
    net.bridge.bridge-nf-call-ip6tables = 1
    net.ipv4.ip_forward = 1
    EOF
 
  1. 启用内核参数without reboot
    [23:07:40] root@kubernetes-template-os:~ # sysctl --system
    * Applying /usr/lib/sysctl.d/10-default-yama-scope.conf ...
    kernel.yama.ptrace_scope = 0
    * Applying /usr/lib/sysctl.d/50-coredump.conf ...
    kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e
    kernel.core_pipe_limit = 16
    * Applying /usr/lib/sysctl.d/50-default.conf ...
    kernel.sysrq = 16
    kernel.core_uses_pid = 1
    kernel.kptr_restrict = 1
    net.ipv4.conf.all.rp_filter = 1
    net.ipv4.conf.all.accept_source_route = 0
    net.ipv4.conf.all.promote_secondaries = 1
    net.core.default_qdisc = fq_codel
    fs.protected_hardlinks = 1
    fs.protected_symlinks = 1
    * Applying /usr/lib/sysctl.d/50-libkcapi-optmem_max.conf ...
    net.core.optmem_max = 81920
    * Applying /usr/lib/sysctl.d/50-pid-max.conf ...
    kernel.pid_max = 4194304
    * Applying /etc/sysctl.d/60-gce-network-security.conf ...
    net.ipv4.tcp_syncookies = 1
    net.ipv4.conf.all.accept_source_route = 0
    net.ipv4.conf.default.accept_source_route = 0
    net.ipv4.conf.all.accept_redirects = 0
    net.ipv4.conf.default.accept_redirects = 0
    net.ipv4.conf.all.secure_redirects = 1
    net.ipv4.conf.default.secure_redirects = 1
    net.ipv4.ip_forward = 0
    net.ipv4.conf.all.send_redirects = 0
    net.ipv4.conf.default.send_redirects = 0
    net.ipv4.conf.all.rp_filter = 1
    net.ipv4.conf.default.rp_filter = 1
    net.ipv4.icmp_echo_ignore_broadcasts = 1
    net.ipv4.icmp_ignore_bogus_error_responses = 1
    net.ipv4.conf.all.log_martians = 1
    net.ipv4.conf.default.log_martians = 1
    kernel.randomize_va_space = 2
    kernel.panic = 10
    * Applying /etc/sysctl.d/99-sysctl.conf ...
    * Applying /etc/sysctl.d/k8s.conf ...
    net.bridge.bridge-nf-call-iptables = 1
    net.bridge.bridge-nf-call-ip6tables = 1
    net.ipv4.ip_forward = 1
    * Applying /etc/sysctl.conf ...
  2. 结果验证
    [23:09:10] root@kubernetes-template-os:~ # sysctl net.bridge.bridge-nf-call-iptables net.bridge.bridge-nf-call-ip6tables net.ipv4.ip_forward
    net.bridge.bridge-nf-call-iptables = 1
    net.bridge.bridge-nf-call-ip6tables = 1
    net.ipv4.ip_forward = 1
    ## 验证 br_netfilter, overlay
    [23:09:14] root@kubernetes-template-os:~ # lsmod | grep br_netfilter
    br_netfilter 32768 0
    bridge 393216 1 br_netfilter
    [23:10:06] root@kubernetes-template-os:~ # lsmod | grep overlay
    overlay 188416 0
 
 

配置cgroup驱动


在Linux中CGroup的功能是用于限制分配给进程的资源,Kubernetes中的Kubelet与CRI都需要对cgroup控制组强势执行Pod的资源控制

注意:kubelet与CRI必须使用同一个cgroup,避免资源压力大造成的不稳定

Kubernetes支持二种cgroup

  1. cgroupfs
    • cgroupfs是kubelet默认使用的cgroup驱动,但是当使用systemd初始化系统时,不建议使用cgroupfs
  1. systemd
    • systemd 与 cgroup 集成紧密,并将为每个 systemd 单元分配一个 cgroup。 因此,如果你 systemd 用作初始化系统,同时使用 cgroupfs 驱动,则系统中会存在两个不同的 cgroup 管理器
    • 修改kubelet的cgroup驱动,编辑KubeletConfiguration 的 cgroupDriver 选项,并将其设置为 systemd。例如:
      apiVersion: kubelet.config.k8s.io/v1beta1
      kind: KubeletConfiguration
      ...
      cgroupDriver: systemd

CRI安装


CRI版本说明

Kubernetes 从 1.26 版本开始仅适用于 v1 版本的容器运行时(CRI)API。早期版本默认为 v1 版本, 但是如果容器运行时不支持 v1 版本的 API, 则 kubelet 会回退到使用(已弃用的)v1alpha2 版本的 API。

CRI支持选择

  1. containerd
  2. CRI-O
  3. Docker Engine
  4. Mirantis Container Runtime

Containerd配置

选择使用containerd作为CRI,官方文档提供了三种安装方式

  1. 官方二进制,https://github.com/containerd/containerd/blob/main/docs/getting-started.md#option-1-from-the-official-binaries,共需要安装三个组件
  2. 使用apt-get 或者 dnf(docker官方YUM源)
    • Docker官方YUM源的Containerd集成了runcf,但是不包含cni-plugins
  3. 源码安装

YUM安装

  1. 配置YUM仓库
    [01:29:01] root@kubernetes-template-os:~ # dnf install -y yum-utils
    Last metadata expiration check: 1:32:41 ago on Sun 15 Oct 2023 11:56:31 PM CST.
    Dependencies resolved.
    ============================================================================================================================================================================================================
    Package Architecture Version Repository Size
    ============================================================================================================================================================================================================
    Installing:
    yum-utils noarch 4.0.21-23.el8 baseos 80 k
    Transaction Summary
    ============================================================================================================================================================================================================
    Install 1 Package
    Total download size: 80 k
    Installed size: 23 k
    Downloading Packages:
    yum-utils-4.0.21-23.el8.noarch.rpm 760 kB/s | 80 kB 00:00
    ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Total 107 kB/s | 80 kB 00:00
    Running transaction check
    Transaction check succeeded.
    Running transaction test
    Transaction test succeeded.
    Running transaction
    Preparing : 1/1
    Installing : yum-utils-4.0.21-23.el8.noarch 1/1
    Running scriptlet: yum-utils-4.0.21-23.el8.noarch 1/1
    Verifying : yum-utils-4.0.21-23.el8.noarch 1/1
    Installed:
    yum-utils-4.0.21-23.el8.noarch
    Complete!
    [01:33:07] root@kubernetes-template-os:~ # yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
    Adding repo from: https://download.docker.com/linux/centos/docker-ce.repo
 
 
  1. 安装最新版本Docker engine
    [01:33:16] root@kubernetes-template-os:~ # dnf install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
    Docker CE Stable - x86_64 509 kB/s | 50 kB 00:00
    Last metadata expiration check: 0:00:01 ago on Mon 16 Oct 2023 01:38:21 AM CST.
    Dependencies resolved.
    ============================================================================================================================================================================================================
    Package Architecture Version Repository Size
    ============================================================================================================================================================================================================
    Installing:
    containerd.io x86_64 1.6.24-3.1.el8 docker-ce-stable 34 M
    docker-buildx-plugin x86_64 0.11.2-1.el8 docker-ce-stable 13 M
    docker-ce x86_64 3:24.0.6-1.el8 docker-ce-stable 24 M
    docker-ce-cli x86_64 1:24.0.6-1.el8 docker-ce-stable 7.2 M
    docker-compose-plugin x86_64 2.21.0-1.el8 docker-ce-stable 13 M
    Installing dependencies:
    checkpolicy x86_64 2.9-1.el8 baseos 348 k
    container-selinux noarch 2:2.221.0-1.module_el8+653+feef7bfe appstream 69 k
    docker-ce-rootless-extras x86_64 24.0.6-1.el8 docker-ce-stable 4.9 M
    fuse-common x86_64 3.3.0-17.el8 baseos 22 k
    fuse-overlayfs x86_64 1.12-1.module_el8+454+d7ef4b8d appstream 70 k
    fuse3 x86_64 3.3.0-17.el8 baseos 54 k
    fuse3-libs x86_64 3.3.0-17.el8 baseos 95 k
    libcgroup x86_64 0.41-19.el8 baseos 70 k
    libslirp x86_64 4.4.0-1.module_el8+487+8e42a277 appstream 70 k
    policycoreutils-python-utils noarch 2.9-24.el8 baseos 260 k
    python3-audit x86_64 3.0.7-5.el8 baseos 87 k
    python3-libsemanage x86_64 2.9-9.el8 baseos 128 k
    python3-policycoreutils noarch 2.9-24.el8 baseos 2.3 M
    python3-setools x86_64 4.3.0-5.el8 baseos 627 k
    slirp4netns x86_64 1.2.1-1.module_el8+661+d1afb926 appstream 56 k
    Enabling module streams:
    container-tools rhel8
    Transaction Summary
    ============================================================================================================================================================================================================
    Install 20 Packages
 
 
  1. 也可以安装指定版本
    [01:41:23] root@kubernetes-template-os:~ # dnf list docker-ce --showduplicates | sort -r
    Last metadata expiration check: 0:03:11 ago on Mon 16 Oct 2023 01:38:21 AM CST.
    Installed Packages
    docker-ce.x86_64 3:24.0.6-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.6-1.el8 @docker-ce-stable
    docker-ce.x86_64 3:24.0.5-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.4-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.3-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.2-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.1-1.el8 docker-ce-stable
    docker-ce.x86_64 3:24.0.0-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.6-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.5-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.4-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.3-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.2-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.1-1.el8 docker-ce-stable
    docker-ce.x86_64 3:23.0.0-1.el8 docker-ce-stable
    dnf install docker-ce-<VERSION_STRING> docker-ce-cli-<VERSION_STRING> containerd.io docker-buildx-plugin docker-compose-plugin

Containerd配置文件

  1. 生成默认配置城文件
    [03:04:54] root@kubernetes-template-os:~ # containerd config default > /etc/containerd/config.toml
  1. 配置systemd cgroup
    [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
    ...
    [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
    SystemdCgroup = true

安装Kubernetes软件包

https://v1-27.docs.kubernetes.io/zh-cn/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl

  1. 配置YUM源
    cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
    enabled=1
    gpgcheck=1
    gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
    exclude=kubelet kubeadm kubectl
    EOF
    ## 查看YUM源
    [03:11:26] root@kubernetes-template-os:~ # cat /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-$basearch
    enabled=1
    gpgcheck=1
    gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
    exclude=kubelet kubeadm kubectl
    cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
    enabled=1
    gpgcheck=1
    gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
    exclude=kubelet kubeadm kubectl
    EOF
    ## 查看YUM源
    [03:11:26] root@kubernetes-template-os:~ # cat /etc/yum.repos.d/kubernetes.repo
    [kubernetes]
    name=Kubernetes
    baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-$basearch
    enabled=1
    gpgcheck=1
    gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
    exclude=kubelet kubeadm kubectl
  1. 关闭selinux
    • 方法一,setenforce 0
    • 方法二,sed -i ‘s/^SELINUX=enforcing$/SELINUX=permissive/’ /etc/selinux/config
  2. 安装kubelet、kubectl、kubeadm
    dnf install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
    systemctl enable --now kubelet
  1. Kubernetes shell自动补全
    echo 'source <(kubectl completion bash)' >>~/.bashrc
    echo 'source <(kubeadm completion bash)' >>~/.bashrc
    source ~/.bashrc

     

posted @   MacoPlus  阅读(19)  评论(0编辑  收藏  举报
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