k8s 使本地集群支持 LoadBalancer 服务
为了使本地集群支持 LoadBalancer 服务，可以参考以下两种实现方案：
这里我们选择使用 metalLB。
metalLB 的部署很简单，直接使用 yaml 文件部署：
kubectl apply -f https://raw.githubusercontent.com/google/metallb/v0.8.3/manifests/metallb.yaml
具体参考 https://metallb.universe.tf/installation/
部署完成后需要为 LoadBalancer 服务选择一个特定的 IP 地址池，这里通过 configmap 来创建。
下面是一个简单示例：
$ cat metallb-cm.yaml
apiVersion: v1
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 192.168.1.58-192.168.1.60
kubectl create -f metallb-cm.yaml
测试
创建一个 Nginx 的服务，服务类型为 LoadBalancer：
apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: nginx
spec:
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1
ports:
- name: http
containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx
spec:
ports:
- name: http
port: 80
protocol: TCP
targetPort: 80
selector:
app: nginx
type: LoadBalancer
服务创建运行之后，可以列出服务信息：
kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP 7d
nginx LoadBalancer 10.96.245.212 10.211.55.240 80:32207/TCP 54m
这里就发现，LoadBalancer 类型的服务，分配到了我们地址池中的第一个 IP。
附录
https://raw.githubusercontent.com/google/metallb/v0.8.3/manifests/metallb.yaml
apiVersion: v1
kind: Namespace
metadata:
labels:
app: metallb
name: metallb-system
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
labels:
app: metallb
name: speaker
namespace: metallb-system
spec:
allowPrivilegeEscalation: false
allowedCapabilities:
- NET_ADMIN
- NET_RAW
- SYS_ADMIN
fsGroup:
rule: RunAsAny
hostNetwork: true
hostPorts:
- max: 7472
min: 7472
privileged: true
runAsUser:
rule: RunAsAny
seLinux:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
volumes:
- '*'
---
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
app: metallb
name: controller
namespace: metallb-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
app: metallb
name: speaker
namespace: metallb-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app: metallb
name: metallb-system:controller
rules:
- apiGroups:
- ''
resources:
- services
verbs:
- get
- list
- watch
- update
- apiGroups:
- ''
resources:
- services/status
verbs:
- update
- apiGroups:
- ''
resources:
- events
verbs:
- create
- patch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
app: metallb
name: metallb-system:speaker
rules:
- apiGroups:
- ''
resources:
- services
- endpoints
- nodes
verbs:
- get
- list
- watch
- apiGroups:
- ''
resources:
- events
verbs:
- create
- patch
- apiGroups:
- extensions
resourceNames:
- speaker
resources:
- podsecuritypolicies
verbs:
- use
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app: metallb
name: config-watcher
namespace: metallb-system
rules:
- apiGroups:
- ''
resources:
- configmaps
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app: metallb
name: metallb-system:controller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: metallb-system:controller
subjects:
- kind: ServiceAccount
name: controller
namespace: metallb-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
app: metallb
name: metallb-system:speaker
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: metallb-system:speaker
subjects:
- kind: ServiceAccount
name: speaker
namespace: metallb-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app: metallb
name: config-watcher
namespace: metallb-system
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: config-watcher
subjects:
- kind: ServiceAccount
name: controller
- kind: ServiceAccount
name: speaker
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
labels:
app: metallb
component: speaker
name: speaker
namespace: metallb-system
spec:
selector:
matchLabels:
app: metallb
component: speaker
template:
metadata:
annotations:
prometheus.io/port: '7472'
prometheus.io/scrape: 'true'
labels:
app: metallb
component: speaker
spec:
containers:
- args:
- --port=7472
- --config=config
env:
- name: METALLB_NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: METALLB_HOST
valueFrom:
fieldRef:
fieldPath: status.hostIP
image: metallb/speaker:v0.8.2
imagePullPolicy: IfNotPresent
name: speaker
ports:
- containerPort: 7472
name: monitoring
resources:
limits:
cpu: 100m
memory: 100Mi
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_ADMIN
- NET_RAW
- SYS_ADMIN
drop:
- ALL
readOnlyRootFilesystem: true
hostNetwork: true
nodeSelector:
beta.kubernetes.io/os: linux
serviceAccountName: speaker
terminationGracePeriodSeconds: 0
tolerations:
- effect: NoSchedule
key: node-role.kubernetes.io/master
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: metallb
component: controller
name: controller
namespace: metallb-system
spec:
revisionHistoryLimit: 3
selector:
matchLabels:
app: metallb
component: controller
template:
metadata:
annotations:
prometheus.io/port: '7472'
prometheus.io/scrape: 'true'
labels:
app: metallb
component: controller
spec:
containers:
- args:
- --port=7472
- --config=config
image: metallb/controller:v0.8.2
imagePullPolicy: IfNotPresent
name: controller
ports:
- containerPort: 7472
name: monitoring
resources:
limits:
cpu: 100m
memory: 100Mi
securityContext:
allowPrivilegeEscalation: false
capabilities:
drop:
- all
readOnlyRootFilesystem: true
nodeSelector:
beta.kubernetes.io/os: linux
securityContext:
runAsNonRoot: true
runAsUser: 65534
serviceAccountName: controller
terminationGracePeriodSeconds: 0