部署之前要先了解熟悉k8s中的service概念。service一共分为4种类型，分别为ClusterIP、NodePort、LoadBalancer 和 ExternalName。默认是 ClusterIP。这里不一一详细介绍！
MetalLB 介绍
MetalLB 是裸机 Kubernetes 集群的负载均衡器实现，使用标准路由协议。Kubernetes 官方并没有提供 LoadBalancer 的实现。各家云厂商有提供实现，但假如不是运行在这些云环境上，创建的 LoadBalancer Service 会一直处于 Pending 状态。
MetalLB 提供了两个功能：
地址分配：当创建 LoadBalancer Service 时，MetalLB 会为其分配 IP 地址。这个 IP 地址是从预先配置的 IP 地址库获取的。同样，当 Service 删除后，已分配的 IP 地址会重新回到地址库。
对外广播：分配了 IP 地址之后，需要让集群外的网络知道这个地址的存在。MetalLB 使用了标准路由协议实现：ARP、NDP 或者 BGP。
广播的方式有两种，第一种是 Layer 2 模式，使用 ARP（ipv4）/NDP（ipv6） 协议；第二种是 BPG。
今天部署以 Layer2 模式，是基于 OSI 二层的实现。
MetalLB 运行时有两种工作负载：
- Controler：Deployment，用于监听 Service 的变更，分配/回收 IP 地址。
- Speaker：DaemonSet，对外广播 Service 的 IP 地址。
部署
//metallb_ns_ds.yaml
apiVersion: v1
kind: Namespace
metadata:
name: metallb-system
labels:
app: metallb
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
labels:
app: metallb
name: controller
spec:
allowPrivilegeEscalation: false
allowedCapabilities: []
allowedHostPaths: []
defaultAddCapabilities: []
defaultAllowPrivilegeEscalation: false
fsGroup:
ranges:
- max: 65535
min: 1
rule: MustRunAs
hostIPC: false
hostNetwork: false
hostPID: false
privileged: false
readOnlyRootFilesystem: true
requiredDropCapabilities:
- ALL
runAsUser:
ranges:
- max: 65535
min: 1
rule: MustRunAs
seLinux:
rule: RunAsAny
supplementalGroups:
ranges:
- max: 65535
min: 1
rule: MustRunAs
volumes:
- configMap
- secret
- emptyDir
---
apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
labels:
app: metallb
name: speaker
spec:
allowPrivilegeEscalation: false
allowedCapabilities:
- NET_RAW
allowedHostPaths: []
defaultAddCapabilities: []
defaultAllowPrivilegeEscalation: false
fsGroup:
rule: RunAsAny
hostIPC: false
hostNetwork: true
hostPID: false
hostPorts:
- max: 7472
min: 7472
- max: 7946
min: 7946
privileged: true
readOnlyRootFilesystem: true
requiredDropCapabilities:
- ALL
runAsUser:
rule: RunAsAny
seLinux:
rule: RunAsAny
supplementalGroups:
rule: RunAsAny
volumes:
- configMap
- secret
- emptyDir
---
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
- apiGroups:
- ''
resources:
- services/status
verbs:
- update
- apiGroups:
- ''
resources:
- events
verbs:
- create
- patch
- apiGroups:
- policy
resourceNames:
- controller
resources:
- podsecuritypolicies
verbs:
- use
---
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: ["discovery.k8s.io"]
resources:
- endpointslices
verbs:
- get
- list
- watch
- apiGroups:
- ''
resources:
- events
verbs:
- create
- patch
- apiGroups:
- policy
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: Role
metadata:
labels:
app: metallb
name: pod-lister
namespace: metallb-system
rules:
- apiGroups:
- ''
resources:
- pods
verbs:
- list
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
labels:
app: metallb
name: controller
namespace: metallb-system
rules:
- apiGroups:
- ''
resources:
- secrets
verbs:
- create
- apiGroups:
- ''
resources:
- secrets
resourceNames:
- memberlist
verbs:
- list
- apiGroups:
- apps
resources:
- deployments
resourceNames:
- controller
verbs:
- get
---
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: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app: metallb
name: pod-lister
namespace: metallb-system
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: pod-lister
subjects:
- kind: ServiceAccount
name: speaker
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
app: metallb
name: controller
namespace: metallb-system
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: controller
subjects:
- kind: ServiceAccount
name: controller
---
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
- --log-level=info
env:
- name: METALLB_NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
- name: METALLB_HOST
valueFrom:
fieldRef:
fieldPath: status.hostIP
- name: METALLB_ML_BIND_ADDR
valueFrom:
fieldRef:
fieldPath: status.podIP
- name: METALLB_ML_LABELS
value: "app=metallb,component=speaker"
- name: METALLB_ML_SECRET_KEY
valueFrom:
secretKeyRef:
name: memberlist
key: secretkey
image: quay.io/metallb/speaker:v0.12.1
name: speaker
ports:
- containerPort: 7472
name: monitoring
- containerPort: 7946
name: memberlist-tcp
- containerPort: 7946
name: memberlist-udp
protocol: UDP
livenessProbe:
httpGet:
path: /metrics
port: monitoring
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
readinessProbe:
httpGet:
path: /metrics
port: monitoring
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
securityContext:
allowPrivilegeEscalation: false
capabilities:
add:
- NET_RAW
drop:
- ALL
readOnlyRootFilesystem: true
hostNetwork: true
nodeSelector:
kubernetes.io/os: linux
serviceAccountName: speaker
terminationGracePeriodSeconds: 2
tolerations:
- effect: NoSchedule
key: node-role.kubernetes.io/master
operator: Exists
---
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
- --log-level=info
env:
- name: METALLB_ML_SECRET_NAME
value: memberlist
- name: METALLB_DEPLOYMENT
value: controller
image: quay.io/metallb/controller:v0.12.1
name: controller
ports:
- containerPort: 7472
name: monitoring
livenessProbe:
httpGet:
path: /metrics
port: monitoring
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
readinessProbe:
httpGet:
path: /metrics
port: monitoring
initialDelaySeconds: 10
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
securityContext:
allowPrivilegeEscalation: false
capabilities:
drop:
- all
readOnlyRootFilesystem: true
nodeSelector:
kubernetes.io/os: linux
securityContext:
runAsNonRoot: true
runAsUser: 65534
fsGroup: 65534
serviceAccountName: controller
terminationGracePeriodSeconds: 0
//metallb_cm.yaml
apiVersion: v1
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 192.168.136.240-192.168.136.250 #地址池
以上2个yaml文件直接apply，等metallb起来之后在创建一个服务测试，正常你会的到如下
通过external-ip去加端口去访问服务
//正常会返回tomcat首页
curl 192.168.136.240:8080svc.yaml如下
apiVersion: v1
kind: Service
metadata:
name: tomcat-svc
namespace: web
labels:
app: tomcat
spec:
selector:
app: tomcat
type: LoadBalancer
ports:
- name: web
port: 8080
targetPort: app-port
更多详情请查看官方文档：https://metallb.universe.tf/
