kind多节点集群¶
在 kind集群 可以部署多个集群，不过默认部署的集群都是单个节点的，看上去和 minikube 并没有太大差别，只能验证应用功能，而不能实际演练Kubernetes集群的功能。
kind的真正功能在于部署多节点集群(multi-node clusters)，这种部署提供了完整的集群模拟。
kind官方网站提供了 kind-example-config ，可以通过以下命令创建一个定制的集群:
kind create cluster --config kind-example-config.yaml
多节点集群实践¶
配置3个管控节点，5个工作节点的集群配置文件如下：
kind构建3个管控节点，5个工作节点集群配置¶
# a cluster with 3 control-plane nodes and 5 workers
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: control-plane
- role: control-plane
- role: worker
- role: worker
- role: worker
- role: worker
- role: worker
执行创建集群，集群命名为
dev:
kind构建3个管控节点，5个工作节点集群配置¶
export CLUSTER_NAME=dev
export reg_name='kind-registry'
kind create cluster --name "${CLUSTER_NAME}" --config kind-config.yaml
备注
为方便使用， 建议 采用 kind集群本地Registry 中脚本方法(配置文件相同，但增加了创建本地Registry步骤)。
备注
如果确实下载困难，可以参考 kind User Guide: Working Offline 先下载镜像，打包后恢复镜像方法来部署。
ARM构建kind集群fix方法¶
我在 Asahi Linux 上创建 dev 集群启动报错，原因是 kind 官方提供的 kindest/node 镜像是multi架构的，在ARM环境会存在架构错误，详见 排查kind集群创建失败 。 workaround 的方法如下:
针对ARM架构创建指定平台架构的镜像:
构建ARM架构的kind镜像¶
cat << EOF > Dockerfile
FROM --platform=arm64 kindest/node:v1.25.3
RUN arch
EOF
docker build -t kindest/node:v1.25.3-arm64 .
备注
制作 Docker 镜像 时，可以通过 Dokerfile指定处理器架构 来实现
此时执行
docker images就会看到如下镜像:
针对ARM的镜像¶
REPOSITORY TAG IMAGE ID CREATED SIZE
kindest/node v1.25.3-arm64 c94e1357ad6f About an hour ago 824MB
kindest/node v1.25.3 aa7084fa36af 13 days ago 824MB
...
然后执行以下命令使用特定ARM64镜像创建集群:
指定ARM镜像创建kind集群¶
kind create cluster --name dev --config kind-config.yaml --image kindest/node:v1.25.3-arm64
则正常完成kind集群创建，输出信息:
指定ARM镜像创建kind集群的正常输出信息¶
Creating cluster "dev" ...
✓ Ensuring node image (kindest/node:v1.25.3-arm64) 🖼
✓ Preparing nodes 📦 📦 📦 📦 📦 📦 📦 📦
✓ Configuring the external load balancer ⚖
✓ Writing configuration 📜
✓ Starting control-plane 🕹
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
✓ Joining more control-plane nodes 🎮
✓ Joining worker nodes 🚜
Set kubectl context to "kind-dev"
You can now use your cluster with:
kubectl cluster-info --context kind-dev
Not sure what to do next? 😅 Check out https://kind.sigs.k8s.io/docs/user/quick-start/
检查¶
检查集群:
kubectl cluster-info --context kind-dev
状态如下:
Kubernetes control plane is running at https://127.0.0.1:44963
CoreDNS is running at https://127.0.0.1:44963/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
完成以后检查集群:
kubectl --context kind-dev get nodes
可以看到创建的集群节点如下:
NAME STATUS ROLES AGE VERSION
dev-control-plane Ready control-plane 5m6s v1.25.3
dev-control-plane2 Ready control-plane 4m52s v1.25.3
dev-control-plane3 Ready control-plane 4m v1.25.3
dev-worker Ready <none> 3m54s v1.25.3
dev-worker2 Ready <none> 3m54s v1.25.3
dev-worker3 Ready <none> 3m54s v1.25.3
dev-worker4 Ready <none> 3m54s v1.25.3
dev-worker5 Ready <none> 3m54s v1.25.3
通过 docker ps 命令可以看到，kind还多启动了一个容器来运行haproxy，以提供外部访问这个集群的apiserver的负载均衡分发，例如以下案例中端口 40075 就是访问该集群的apiserver端口(见第一行):
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
22b5211339aa kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes 127.0.0.1:40075->6443/tcp dev-control-plane
fe81ebfaf493 kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes dev-worker2
d1d88de19435 kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes dev-worker4
7af7558e3339 kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes dev-worker3
d4cd1a9851ca kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes dev-worker5
2c84abeb9eeb kindest/haproxy:v20220607-9a4d8d2a "haproxy -sf 7 -W -d…" 6 minutes ago Up 6 minutes 127.0.0.1:44963->6443/tcp dev-external-load-balancer
e2fdcb424eab kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes dev-worker
619b562dc7bb kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes 127.0.0.1:45187->6443/tcp dev-control-plane3
2d40652bf4f4 kindest/node:v1.25.3-arm64 "/usr/local/bin/entr…" 6 minutes ago Up 6 minutes 127.0.0.1:35769->6443/tcp dev-control-plane2
所以，在运行 kind 的服务器上执行:
kubectl cluster-info
可以看到如下输出:
Kubernetes control plane is running at https://127.0.0.1:44963
CoreDNS is running at https://127.0.0.1:44963/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.