kubernetes集群安裝指南：客戶端安裝及各組件認(rèn)證文件創(chuàng)建

大多情況，證書(shū)用于服務(wù)安全訪問(wèn)（即https訪問(wèn)）所需要，在kubernetes集群中，如果關(guān)閉了匿名訪問(wèn)，開(kāi)啟了集群HTTPS訪問(wèn)以及TLS雙向認(rèn)證；如：worker節(jié)點(diǎn)組件HTTPS訪問(wèn)apiserver服務(wù)時(shí)，Apiserver還需要驗(yàn)證客戶端是否合法，此時(shí)就需要為worker節(jié)點(diǎn)上的組件生成kubeconfig認(rèn)證文件用于連接apiserver。

1. 基本設(shè)置

1.1 變量設(shè)置

PACKAGE=kubernetes-server-v1.12.0-linux-amd64.tar.gz
K8S_DOWNLOAD_URL=https://github.com/devops-apps/download/raw/master/kubernetes/$PACKAGE
K8S_CONF_PATH=/etc/k8s/kubernetes
K8S_KUBECONFIG_PATH=/etc/k8s/kubeconfig
KUBE_APISERVER=https://dev-kube-api.mo9.com
BOOTSTRAP_TOKEN=$(head -c 16 /dev/urandom | od -An -t x | tr -d ' ')

1.2 kubectl、kubens工具集安裝

sudo wget $K8S_DOWNLOAD_URL -P /root/software
cd $SOFTWARE 
tar -xzfkubernetes-server-v1.12.0-linux-amd64.tar.gz -C ./
cp -fp kubernetes/server/bin/{kubectl,kubens} /usr/local/sbin

1.3 創(chuàng)建認(rèn)證文件存放目錄

if [ ! -d "$K8S_CONF_PATH" ]; then
     mkdir -p $K8S_CONF_PATH
fi

if [ ! -d "$K8S_KUBECONFIG_PATH" ]; then
     mkdir -p $K8S_KUBECONFIG_PATH
fi

2. 創(chuàng)建 TLS Bootstrapping Token

cat > ${K8S_CONF_PATH}/token.csv <<EOF
${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

• bootstrapping token文件主要用于為apiserver開(kāi)啟tocken認(rèn)證而創(chuàng)建，如果沒(méi)有開(kāi)啟apiserver token認(rèn)證可以不用創(chuàng)建此文件；

3 kubeconfig文件創(chuàng)建

3.1 創(chuàng)建kube-controller-manager kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=${CA_DIR}/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-controller-manager.kubeconfig

kubectl config set-credentials system:kube-controller-manager \
  --client-certificate=${CA_DIR}/kube-controller-manager.pem \
  --client-key=${CA_DIR}/kube-controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-controller-manager.kubeconfig

kubectl config set-context system:kube-controller-manager \
  --cluster=kubernetes \
  --user=system:kube-controller-manager \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-controller-manager.kubeconfig

kubectl config use-context system:kube-controller-manager \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-controller-manager.kubeconfig

3.2 創(chuàng)建kube-shceduler kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=${CA_DIR}/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-scheduler.kubeconfig

kubectl config set-credentials system:kube-scheduler \
  --client-certificate=${CA_DIR}/kube-scheduler.pem \
  --client-key=${CA_DIR}/kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-scheduler.kubeconfig

kubectl config set-context system:kube-scheduler \
  --cluster=kubernetes \
  --user=system:kube-scheduler \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-scheduler.kubeconfig

kubectl config use-context system:kube-scheduler \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-scheduler.kubeconfig

3.3 創(chuàng)建kubelet bootstrapping kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=${CA_DIR}/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/bootstrap.kubeconfig

kubectl config set-credentials kubelet-bootstrap \
  --token=${BOOTSTRAP_TOKEN} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/bootstrap.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=kubelet-bootstrap \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/bootstrap.kubeconfig

kubectl config use-context default \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/bootstrap.kubeconfig

• bootstrapping文件主要用于apiserver給kubelet證書(shū)做自動(dòng)輪轉(zhuǎn)，使用該文件，apiserver會(huì)自動(dòng)給kubelet頒發(fā)服務(wù)端證書(shū)以及證書(shū)密鑰，從而不必為kubelet證書(shū)

3.4 創(chuàng)建kube-proxy kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=${CA_DIR}/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-proxy.kubeconfig

kubectl config set-credentials kube-proxy \
  --client-certificate=${CA_DIR}/kube-proxy.pem \
  --client-key=${CA_DIR}/kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-proxy.kubeconfig

kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-proxy.kubeconfig

kubectl config use-context default \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kube-proxy.kubeconfig

3.5 創(chuàng)建kubectl kubeconfig文件

kubectl config set-cluster kubernetes \
  --certificate-authority=${CA_DIR}/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kubectl.kubeconfig

kubectl config set-credentials admin \
  --client-certificate=${CA_DIR}/admin.pem \
  --client-key=${CA_DIR}/admin-key.pem \
  --embed-certs=true \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kubectl.kubeconfig

kubectl config set-context kubernetes \
  --cluster=kubernetes \
  --user=admin \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kubectl.kubeconfig

kubectl config use-context kubernetes \
  --kubeconfig=${K8S_KUBECONFIG_PATH}/kubectl.kubeconfig

• --certificate-authority：驗(yàn)證 kube-apiserver 證書(shū)的根證書(shū)；
• --client-certificate、--client-key：剛生成的 admin 證書(shū)和私鑰，連接 kube-apiserver 時(shí)使用；
• --embed-certs=true：將 ca.pem 和 admin.pem 證書(shū)內(nèi)容嵌入到生成的 kubectl.kubeconfig 文件中(不加時(shí)，寫(xiě)入的是證書(shū)文件路徑)；

備注：kubeconfig文件是用于安全連接apiserver服務(wù)的認(rèn)證文件。

4 同步token文件及kubeconfig文件到相應(yīng)的節(jié)點(diǎn)

• master節(jié)點(diǎn)：

  cd $K8S_KUBECONFIG_PATH
  ansible master_k8s_vgs -m copy -a \
  "src=kube-controller-manager.kubeconfig dest=$K8S_KUBECONFIG_PATH/ " -b
  ansible master_k8s_vgs -m copy -a \
  "src=kube-scheduler.kubeconfig dest=$K8S_KUBECONFIG_PATH/ " -b

• worker節(jié)點(diǎn)

  cd $K8S_KUBECONFIG_PATH
  ansible worker_k8s_vgs -m copy -a \
  "src=bootstrap.kubeconfig dest=$K8S_KUBECONFIG_PATH/ " -b
  ansible worker_k8s_vgs -m copy -a \
  "src=kube-proxy.kubeconfig dest=$K8S_KUBECONFIG_PATH/ " -b

• kubeconfig文件主要用于各組件在通過(guò)https訪問(wèn)apiserver時(shí)所需要的認(rèn)證的文件，該文件包括對(duì)應(yīng)組件的服務(wù)端證書(shū)、證書(shū)私鑰、ca根證書(shū)以及apiserver的訪問(wèn)地址

創(chuàng)建完kubernetes集群組件相關(guān)認(rèn)證文件后，接下來(lái)正式部署kubernetes集群相關(guān)組件etcd集群，請(qǐng)參考：kubernetes集群安裝指南：etcd集群部署