k8s一路安裝到flannel網路時卡主了我不少時間，檢視大量資料無法解決問題，始終報錯，flanel容器不斷重啟，CrashLoopBackoff，截圖如下：

容器截圖如下：

Failed to create SubnetManager: error retrieving pod spec for 'kube-system/kube-flannel-ds-amd64-jlc9f': Get https://10.0.0.1:443/api/v1/namespaces/kube-system/pods/kube-flannel-ds-amd64-jlc9f: dial tcp 10.0.0.1:443: i/o timeout

解決辦法：

ETCD檢視已經建立的網路資源：

 #/opt/apps/etcd/etcdctl ls /coreos.com/network/subnets/

　　/coreos.com/network/subnets/172.7.76.0-24

　　# /opt/apps/etcd/etcdctl get /coreos.com/network/config

　　{"Network": "172.7.0.0/16", "Backend": {"Type": "host-gw"}}

　　# /opt/apps/etcd/etcdctl get /coreos.com/network/subnets/172.7.76.0-24

　 {"PublicIP":"192.168.91.76","BackendType":"host-gw"}

　　這是在etcd已經註冊建立好的網路資源，比如我的是172.7.76.0/24網段，這裡要符合2大條件，才能進行容器之間宿主機的pod 容器通訊

1. 檢視自己docker容器的IP網段：

 #ifconfig 
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.7.76.1  netmask 255.255.255.0  broadcast 172.7.76.255

　　這裡設定的網路必須設定與宿主機前面檢視的已經建立的網路資源 172.7.76.0/24 在同一網段，然後請新增設定："bip": "172.7.76.1/24"

# vim /etc/docker/daemon.json 
{
  "graph": "/data/docker",
  "storage-driver": "overlay2",
  "insecure-registries": ["harbor.vv.com"],
  "registry-mirrors": ["https://registry.docker-cn.com"],
  "bip": "172.7.76.1/24",
  "exec-opts": ["native.cgroupdriver=systemd"],
  "live-restore": true
}

2. 檢視k8s cluster-cidr是否是上面查出來的172.7.0.016,大多數是10.244.0.0/16,通常在kube-contrellor-manger配置檔案中有寫

cat opt/kubernetes/cfg/kube-controller-manager.conf 
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \
--v=2 \
--log-dir=/opt/kubernetes/logs \
--leader-elect=true \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1 \
--allocate-node-cidrs=true \
--cluster-cidr=172.7.0.0/16 \
--service-cluster-ip-range=192.168.0.0/24 \
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \
--root-ca-file=/opt/kubernetes/ssl/ca.pem \
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \
--experimental-cluster-signing-duration=87600h0m0s"

踩了好多天坑，今天終於解決了，特此記錄