Kubernetes-Kubectl篇-01-常用命令

kubectl 常见命令

登录命令

根据机器ip使用kubectl登录机器(field-selector):

#!/bin/bash
export targetIp="6.0.90.240"

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

podinfo=`kubectl get pod --all-namespaces --field-selector=status.podIP="$targetIp" -o wide | grep -v NAME | head -n 1 `
ns=`echo ${podinfo} | awk '{print $1}'`
pod=`echo ${podinfo} | awk '{print $2}'`

echo "$kubectl exec -it -n ${ns} ${pod} -- su - root"
kubectl exec -it -n ${ns} ${pod} -- su - root

根据机器ip使用kubectl登录机器(label):

#!/bin/bash
export targetIp="6.3.144.241"

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

podinfo=`kubectl get pod --all-namespaces -l sigma.ali/ip="$targetIp" -o wide | grep -v NAMESPACE`
ns=`echo ${podinfo} | awk '{print $1}'`
pod=`echo ${podinfo} | awk '{print $2}'`

echo "$kubectl exec -it -n ${ns} ${pod} -- su - root"
kubectl exec -it -n ${ns} ${pod} -- su - root

更智能版本的kubectl登录命令：

• 查看KUBECONFIG_DIR目录下有哪些kubeconfig可以用
• 校验目标登录的ip格式
• 查询并解析pod信息
• 查询该pod有哪些容器并展示
• 查询选定的容器有哪些用户(与user_array做交集)，支持自定义输入用户
• 根据以上信息登录目标ip对应pod的选定容器

#!/bin/bash

# 添加特定用户
user_array=("root" "admin" "log")

# 从指定目录获取所有 kubeconfig 文件
KUBECONFIG_DIR="/Users/king/.kube"

# 初始化 kubectl 命令前缀
KUBECTL_CMD="kubectl"

# 确保将信息打印到终端里，即使在函数之间$(...)调用的场景
function print_to_console() {
    printf "%s\n" "$1" >&2
}

# 检查IP地址是否符合正确的格式
function is_valid_ip() {
    local ip=$1
    local valid_regex='^([0-9]{1,3}\.){3}[0-9]{1,3}$'

    if [[ $ip =~ $valid_regex ]]; then
        # 确保每个数字部分小于等于255
        IFS='.' read -r -a octets <<< "$ip"
        for octet in "${octets[@]}"; do
            if ((octet > 255)); then
                return 1
            fi
        done
        return 0
    fi
    return 1
}

KUBECONFIGS=($(find $KUBECONFIG_DIR -maxdepth 1 -name "*.config" -print))

# 检查是否找到 kubeconfig 文件
if [ ${#KUBECONFIGS[@]} -eq 0 ]; then
    print_to_console "没有找到任何 kubeconfig 文件在目录: $KUBECONFIG_DIR"
else
    # 提供给用户选择的菜单，动态生成选项范围提示
    cat << EOF
    ----------------------------------------------
    |*******Please Enter Your Choice:[1-${#KUBECONFIGS[@]}]*******|
    ----------------------------------------------
EOF

    # 输出可供选择的配置文件选项
    for i in "${!KUBECONFIGS[@]}"; do
        print_to_console "*     $(($i + 1)) ${KUBECONFIGS[$i]}"
    done

    # 捕获用户输入并确保在合法范围内
    while true; do
        read -p "please input your choice [1-${#KUBECONFIGS[@]}] (or press Enter to skip): " num
        if [[ -z "$num" ]]; then
            break
        elif [[ "$num" =~ ^[0-9]+$ ]] && [ "$num" -ge 1 ] && [ "$num" -le ${#KUBECONFIGS[@]} ]; then
            selected_config="${KUBECONFIGS[$((num - 1))]}"
            KUBECTL_CMD="kubectl --kubeconfig=$selected_config"
            print_to_console "Using configuration file: $selected_config"
            break
        else
            print_to_console "Invalid choice. Please try again."
        fi
    done
fi

# 输出用户选择的配置文件
selected_config="${KUBECONFIGS[$((num - 1))]}"
print_to_console "You selected: $selected_config"

# 捕获用户输入的targetIP
while true; do
    read -p "please input your target ip: " targetIP

    # 检查输入是否为空和格式有效性
    if [[ -z "$targetIP" ]]; then
        print_to_console "IP 地址不能为空，请重新输入。"
    elif ! is_valid_ip "$targetIP"; then
        print_to_console "无效的IP格式，请输入有效的IP地址。"
    else
        print_to_console "您输入的IP地址是: $targetIP"
        break
    fi
done

# 获取 Pod 信息
podinfo=$($KUBECTL_CMD get pod --all-namespaces --field-selector=status.podIP="$targetIP" -o wide | grep -v NAME | head -n 1)

# 检查 podinfo 是否为空
if [[ -z "$podinfo" ]]; then
    print_to_console "未能获取到对应 IP 的 Pod 信息，退出脚本。"
    exit 1
fi

# 提取命名空间和 Pod 名称
ns=$(echo "${podinfo}" | awk '{print $1}')
pod=$(echo "${podinfo}" | awk '{print $2}')

# 检查 ns 和 pod 是否为空
if [[ -z "$ns" || -z "$pod" ]]; then
    print_to_console "未能提取到命名空间或 Pod 名称，退出脚本。"
    exit 1
fi

print_to_console "Namespace: $ns, Pod: $pod"

# 获取容器列表
containers=($($KUBECTL_CMD get pod $pod -n $ns -o jsonpath='{.spec.containers[*].name}'))
selected_container=""
if [ ${#containers[@]} -gt 0 ]; then
    print_to_console "请选择一个容器 (或直接按 Enter 跳过使用默认容器):"
    for i in "${!containers[@]}"; do
        print_to_console "*      $(($i + 1)) ${containers[$i]}"
    done

    while true; do
        read -p "please input your choice [1-${#containers[@]}] (or press Enter to skip): " container_num
        if [[ -z "$container_num" ]]; then
            break
        elif [[ "$container_num" =~ ^[0-9]+$ ]] && [ "$container_num" -ge 1 ] && [ "$container_num" -le ${#containers[@]} ]; then
            selected_container="${containers[$((container_num - 1))]}"
            print_to_console "Selected container: $selected_container"
            break
        else
            print_to_console "Invalid choice. Please try again."
        fi
    done
fi

# 解析容器中的用户并添加到用户数组中
while IFS=: read -r username _ uid _; do
    if [[ $uid -ge 1000 && $username != "nobody" ]]; then
        user_array+=("$username")
    fi
done <<< "$user_list"

# 显示可供选择的用户列表
print_to_console "请选择一个用户 (或自定义输入):"
for i in "${!user_array[@]}"; do
    print_to_console "*      $(($i + 1)) ${user_array[$i]}"
done
print_to_console "*      $(( ${#user_array[@]} + 1 )) 自定义输入 "

# 捕获用户选择的用户
while true; do
    read -p "please input your choice [1-$(( ${#user_array[@]} + 1 ))]: " user_num
    if [[ "$user_num" =~ ^[0-9]+$ ]] && [ "$user_num" -ge 1 ] && [ "$user_num" -le $(( ${#user_array[@]} + 1 )) ]; then
        if [ "$user_num" -eq $(( ${#user_array[@]} + 1 )) ]; then
            read -p "请输入自定义用户名: " targetUser
        else
            targetUser="${user_array[$((user_num - 1))]}"
        fi
        print_to_console "Selected user: $targetUser"
        break
    else
        print_to_console "Invalid choice. Please try again."
    fi
done

# 执行命令
if [[ -n "$selected_container" ]]; then
    print_to_console "$KUBECTL_CMD exec -it -n ${ns} ${pod} -c ${selected_container} -- su - $targetUser"
    $KUBECTL_CMD exec -it -n ${ns} ${pod} -c ${selected_container} -- su - $targetUser
else
    print_to_console "$KUBECTL_CMD exec -it -n ${ns} ${pod} -- su - $targetUser"
    $KUBECTL_CMD exec -it -n ${ns} ${pod} -- su - $targetUser
fi

查询命令

根据机器ip(field-selector)查询pod:

#!/bin/bash
export fieldKEY="status.podIP"
export fieldVALUE="6.0.90.240"

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl get pod --all-namespaces --field-selector=$fieldKEY=$fieldVALUE -o wide

根据label查询pod:

#!/bin/bash
export labelKEY="sigma.ali/ip"
export labelVALUE="6.0.90.240"

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl get pod --all-namespaces -l $labelKEY=$labelVALUE -o wide

导出yaml

根据机器ip使用kubectl导出机器yaml:

#!/bin/bash
local podName=""
local namespace=""

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl get pod/$podName -n ${namespace} -oyaml

describe

根据namespace和podName进行describe

local namespace="longtermbase"
local podName="inplaceset-antcodebuild-tn1oimjfl-gz00b-0"

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl describe pod $podName -n $namespace

清理terminating的pod

通过清理finalizers实现

local namespace=""
local podName=""

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl patch pod/$podName -n $namespace -p '{"metadata":{"finalizers":null}}'

强制删除

local namespace=""
local podName=""

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

k delete pod/$podName -n $namespace --force --grace-period=0

复制文件到pod容器

local namespace=""
local podName=""
local sourceDir=""
local sourceFile=""
local targetDir=""
local targetFile=""

#alias kubectl='kubectl'
alias kubectl='kubectl --kubeconfig=/Users/king/.kube/sa128.config'

kubectl cp -n linkw $sourceDir/$sourceFile $podName:/targetDir/targetFile