用过 Kubernetes 的用户都知道 Kubernetes API 真的非常庞大。在最新的版本中，从 Pods 和 Deployments 到 Validating Webhook Configuration 和 ResourceQuota，超过 50 个一级对象。如果您是开发人员，我确信这会很容易导致群集配置时出现紊乱。因此，需要一种简化的方法（如 Swarm CLI / API）来部署和管理在 Kubernetes 集群上运行的应用程序。在上一篇文章《Kubernetes 实战教学，手把手教您如何在 K8s 平台上使用 Compose（一）》中，简要的介绍了简化 Kubernetes 部署以及管理的工具 —— Compose，今天将展示如何在 Kubernetes 上运用 Compose 的实战演示。
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测试所用的基础设施
-
Docker 版本：Docker Desktop Community v2.0.1.0；
-
系统：macOS High Sierra v10.13.6；
-
Docker Engine：v18.09.1；
-
Docker Compose：v1.23.2；
-
Kubernetes：v1.13.0；
先决条件
-
点击文尾处“阅读原文”，下载并安装 Docker Desktop Community Edition v2.0.1.0；
-
按下图所示的功能启用 Kubernetes；
验证 Docker Desktop 版本
[Captains-Bay]? > docker version
Client: Docker Engine – Community
Version: 18.09.1
API version: 1.39
Go version: go1.10.6
Git commit: 4c52b90
Built: Wed Jan 9 19:33:12 2019
OS/Arch: darwin/amd64
Experimental: false
Server: Docker Engine – Community
Engine:
Version: 18.09.1
API version: 1.39 (minimum version 1.12)
Go version: go1.10.6
Git commit: 4c52b90
Built: Wed Jan 9 19:41:49 2019
OS/Arch: linux/amd64
Experimental: true
Kubernetes:
Version: v1.12.4
StackAPI: v1beta2
[Captains-Bay]? >
安装 Minikube
curl -Lo minikube
https://storage.googleapis.com/minikube/releases/latest/minikube-darwin-amd64
\
&& chmod +x minikube
验证 Minikube 版本
minikube version
minikube version: v0.32.0
检查 Minikube 状态
minikube status
host: Stopped
kubelet:
apiserver:
开始 Minikube
]? > minikube start
Starting local Kubernetes v1.12.4 cluster…
Starting VM…
Getting VM IP address…
Moving
files into cluster…
Setting up certs…
Connecting to cluster…
Setting up kubeconfig…
Stopping extra container runtimes…
Machine exists, restarting cluster components…
Verifying kubelet health …
Verifying apiserver health ….Kubectl is now configured to use the cluster.
Loading cached images from config file.
Everything looks great. Please enjoy minikube!
By now, you should be able to see context switching happening under UI windows under Kubernetes section as shown below:
检查 Minikube 状态
? > minikube status
host: Running
kubelet: Running
apiserver: Running
kubectl: Correctly Configured: pointing to minikube-vm at 192.168.99.100[Captains-Bay]? >
列出 Minikube 集群节点
kubectl get nodes
NAME STATUS ROLES AGE VERSION
minikube Ready master 12h v1.12.4
创建“compose”命名空间
kubectl create namespace compose
namespace "compose" created
创建“tiller”服务帐户
kubectl -n kube-system create serviceaccount tiller
serviceaccount "tiller" created
授予对集群的访问权限
kubectl -n kube-system create clusterrolebinding tiller –clusterrole cluster-admin –serviceaccount kube-system:tiller
clusterrolebinding "tiller" created
初始化 Helm 组件
? > helm init –service-account tiller
$HELM_HOME has been configured at /Users/ajeetraina/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
For more information on securing your installation see:
https://docs.helm.sh/using_helm/\#securing-your-helm-installation
Happy Helming!
验证 Helm 版本
helm version
Client: &version.Version{SemVer:"v2.12.1", GitCommit:"20adb27c7c5868466912eebdf6664e7390ebe710", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.12.1", GitCommit:"20adb27c7c5868466912eebdf6664e7390ebe710", GitTreeState:"clean"}
部署 etcd operator
? > helm install –name etcd-operator stable/etcd-operator –namespace compose
NAME: etcd-operator
LAST DEPLOYED: Fri Jan 11 10:08:06 2019
NAMESPACE: compose
STATUS: DEPLOYED
RESOURCES:
==> v1/ServiceAccount
NAME SECRETS AGE
etcd-operator-etcd-operator-etcd-backup-operator 1 1s
etcd-operator-etcd-operator-etcd-operator 1 1s
etcd-operator-etcd-operator-etcd-restore-operator 1 1s
==> v1beta1/ClusterRole
NAME AGE
etcd-operator-etcd-operator-etcd-operator 1s
==> v1beta1/ClusterRoleBinding
NAME AGE
etcd-operator-etcd-operator-etcd-backup-operator 1s
etcd-operator-etcd-operator-etcd-operator 1s
etcd-operator-etcd-operator-etcd-restore-operator 1s
==> v1/Service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
etcd-restore-operator ClusterIP 10.104.102.245 19999/TCP 1s
==> v1beta1/Deployment
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
etcd-operator-etcd-operator-etcd-backup-operator 1 1 1 0 1s
etcd-operator-etcd-operator-etcd-operator 1 1 1 0 1s
etcd-operator-etcd-operator-etcd-restore-operator 1 1 1 0 1s
==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
etcd-operator-etcd-operator-etcd-backup-operator-7978f8bc4r97s7 0/1 ContainerCreating 0 1s
etcd-operator-etcd-operator-etcd-operator-6c57fff9d5-kdd7d 0/1 ContainerCreating 0 1s
etcd-operator-etcd-operator-etcd-restore-operator-6d787599vg4rb 0/1 ContainerCreating 0 1s
NOTES:
- etcd-operator deployed.
If you would like to deploy an etcd-cluster set cluster.enabled to true in values.yaml
Check the etcd-operator logs
export POD=$(kubectl get pods -l app=etcd-operator-etcd-operator-etcd-operator –namespace compose –output name)
kubectl logs $POD –namespace=compose
? >
创建 etcd 集群
$cat compose-etcd.yaml
apiVersion: "
etcd.database.coreos.com/v1beta2
"
kind: "EtcdCluster"
metadata:
name: "compose-etcd"
namespace: "compose"
spec:
size: 3
version: "3.2.13"
kubectl apply -f compose-etcd.yaml
etcdcluster "compose-etcd" created
这将在 compose 命名空间中引入一个 etcd 集群。
下载 Compose 安装程序
wget
https://github.com/docker/compose-on-kubernetes/releases/download/v0.4.18/installer-darwin
在 Kubernetes 上部署 Compose
./installer-darwin -namespace=compose -etcd-servers=
http://compose-etcd-client:2379
-tag=v0.4.18
INFO[0000] Checking installation state
INFO[0000] Install image with tag "v0.4.18" in namespace "compose"
INFO[0000] Api server: image: "docker/kube-compose-api-server:v0.4.18", pullPolicy: "Always"
INFO[0000] Controller: image: "docker/kube-compose-controller:v0.4.18", pullPolicy: "Always"
确保已启用 Compose Stack 控制器
[Captains-Bay]? > kubectl api-versions| grep compose
compose.docker.com/v1beta1
compose.docker.com/v1beta2
列出 Minikube 的服务
[Captains-Bay]? > minikube service list
|————-|————————————-|—————————–|
| NAMESPACE | NAME | URL |
|————-|————————————-|—————————–|
| compose | compose-api | No node port |
| compose | compose-etcd-client | No node port |
| compose | etcd-restore-operator | No node port |
| default | db1 | No node port |
| default | example-etcd-cluster-client-service |
http://192.168.99.100:32379
|
| default | kubernetes | No node port |
| default | web1 | No node port |
| default | web1-published |
http://192.168.99.100:32511
|
| kube-system | kube-dns | No node port |
| kube-system | kubernetes-dashboard | No node port |
| kube-system | tiller-deploy | No node port |
|————-|————————————-|—————————–|
[Captains-Bay]? >
验证 StackAPI
[Captains-Bay]? > docker version
Client: Docker Engine – Community
Version: 18.09.1
API version: 1.39
Go version: go1.10.6
Git commit: 4c52b90
Built: Wed Jan 9 19:33:12 2019
OS/Arch: darwin/amd64
Experimental: false
Server: Docker Engine – Community
Engine:
Version: 18.09.1
API version: 1.39 (minimum version 1.12)
Go version: go1.10.6
Git commit: 4c52b90
Built: Wed Jan 9 19:41:49 2019
OS/Arch: linux/amd64
Experimental: true
Kubernetes:
Version: v1.12.4
StackAPI: v1beta2
[Captains-Bay]? >
直接使用 Docker Compose 部署 Web 应用程序堆栈
[Captains-Bay]? > docker stack deploy -c docker-compose2.yml myapp4
Waiting for the stack to be stable and running…
db1: Ready [pod status: 1/2 ready, 1/2 pending, 0/2 failed]
web1: Ready [pod status: 2/2 ready, 0/2 pending, 0/2 failed]
Stack myapp4 is stable and running
[Captains-Bay]? > docker stack ls
NAME SERVICES ORCHESTRATOR NAMESPACE
myapp4 2 Kubernetes default
[Captains-Bay]? > kubectl get po
NAME READY STATUS RESTARTS AGE
db1-55959c855d-jwh69 1/1 Running 0 57s
db1-55959c855d-kbcm4 1/1 Running 0 57s
web1-58cc9c58c7-sgsld 1/1 Running 0 57s
web1-58cc9c58c7-tvlhc 1/1 Running 0 57s
因此，我们使用 Docker Compose 文件成功地将一个 Web 应用程序栈部署到运行在 Minikube 中的单节点 Kubernetes 集群上。
