K8s service catalog

Service catalog

Service catalog: https://github.com/kubernetes-incubator/service-catalog, 是 K8s 的一个孵化项目，目标是通过其 K8s 上部署的应用可以通过 service broker 连接外部服务；service broker 也是又一个标准化组织推动：open service broker - https://www.openservicebrokerapi.org/，简单说 service broker 会提供:

• List catalog
• Provision instance
• Service bind
• Service unbind
• Deprovision instance

Service catalog 可以创建下列资源：

• clusterservicebroker: 连接 broker
• service instance: 创建的 instance
• service binding: 绑定 instance，生成 secret

下文提供了更多的信息：
https://medium.com/bitnami-perspectives/service-catalog-in-kubernetes-78c0736e3910

其中提到的 service broker 的 Go 的示例代码：

• https://github.com/kubernetes-incubator/service-catalog/blob/master/contrib/pkg/broker/user_provided/controller/controller.go
• https://github.com/prydonius/mariadb-broker/blob/master/controller/controller.go

安装

使用 helm 安装：

• 启动 minikube，并配置 RBAC: minikube start --extra-config=apiserver.Authorization.Mode=RBAC，同时配置 Tiller。

minikube start --extra-config=apiserver.Authorization.Mode=RBAC
kubectl config current-context
kubectl create clusterrolebinding add-on-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:default

• 配置 repo：helm repo add svc-cat https://svc-catalog-charts.storage.googleapis.com
• 运行 search 确保 repo 正常显示
• 更新 repo：helm repo update
• 安装 service catalog：helm install svc-cat/catalog --name catalog --namespace catalog

➜  ~ helm repo add svc-cat https://svc-catalog-charts.storage.googleapis.com
"svc-cat" has been added to your repositories
➜  ~ helm search service-catalog
NAME            VERSION DESCRIPTION
svc-cat/catalog 0.1.3   service-catalog API server and controller-manag...

• 查看所有的 API: kubectl api-versions，确认 servicecatalog.k8s.io 已经存在。

➜  service-catalog git:(master) ✗ kubectl api-versions
admissionregistration.k8s.io/v1alpha1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1beta1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
batch/v1
batch/v1beta1
batch/v2alpha1
certificates.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1alpha1
rbac.authorization.k8s.io/v1beta1
servicecatalog.k8s.io/v1beta1
settings.k8s.io/v1alpha1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1

使用

参照 https://github.com/gyliu513/mariadb-broker

• 部署 maria db server: kubectl create -f xxx.yaml

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: mariadb-server
  labels:
    app: mariadb-server
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mariadb-server
  template:
    metadata:
      labels:
        app: mariadb-server
    spec:
      containers:
      - name: mariadb-server
        image: mariadb:10.3
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: passw0rd
        ports:
        - containerPort: 3306

• 安装启动 service broker：helm install --name=mariadb-broker charts/mariadb-broker，查看 pod ip，试着访问：http://BROKER_IP:8005/v2/catalog，例如：ssh 登入 minikube，运行：http://172.17.0.8:8005/v2/catalog

{"services":[{"name":"mariadb","id":"3533e2f0-6335-4a4e-9d15-d7c0b90b75b5","description":"MariaDB database","bindable":true,"plan_updateable":false,"tags":null,"requires":null,"metadata":null,"plans":[{"name":"default","id":"b9600ecb-d511-4621-b450-a0fa1738e632","description":"MariaDB database","metadata":null,"free":true,"schemas":null}],"dashboard_client":null}]}

• 创建 cluster service broker：kubectl apply -f examples/1.mariadb-broker.yaml，注意需要修改 broker url 根据上面一部的起动完成的 pod 的 ip；运行 kubectl get clusterservicebroker 查看资源已经创建完成；

➜  service-catalog git:(master) ✗ kubectl get clusterservicebroker
NAME             AGE
mariadb-broker   19m

• 运行 workpress 例子：

➜  service-catalog git:(master) ✗ kubectl apply -f examples/3.wodpress/3.1.wordpress-instance.yaml
serviceinstance "wordpress-mariadb-instance" created
➜  service-catalog git:(master) ✗ kubectl get serviceinstance
NAME                         AGE
wordpress-mariadb-instance   19m

➜  service-catalog git:(master) ✗ kubectl apply -f examples/3.wodpress/3.2.wordpress-binding.yaml
servicebinding "wordpress-mariadb-binding" created
➜  service-catalog git:(master) ✗ kubectl get servicebinding
NAME                        AGE
wordpress-mariadb-binding   19m

➜  service-catalog git:(master) ✗ kubectl apply -f examples/3.wodpress/3.3.wordpress-blog-system.yaml
service "wordpress" created
deployment "wordpress" created

• 查看 wordpress 相应的 service，找到 node port，访问 workdpress。

helm 删除的命令：

• helm del --purge mariadb-broker

Tips

安装 helm，init 完成后由于网的原因，tiller 的 pod 会起不来，解决办法：通过 ssh 登入minikube，手动拉取镜像和 打 tag。

docker pull sapcc/tiller:v2.7.2
docker tag sapcc/tiller:v2.7.2 gcr.io/kubernetes-helm/tiller:v2.7.2

运行 kubectl create clusterrolebinding add-on-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:default 命令配置 Tiller ，使其具有 cluster-admin 访问权限时，可能报错：Error: unknown flag: --clusterrole，这是由于 kubectl 版本太导致的，要升级 kubectl 。