Awesome

ALB -- Another Load Balancer

ALB (Another Load Balancer) is a Kubernetes Gateway powered by OpenResty with years of production experience from Alauda.

Note: We are in the process of preparing the necessary documentation and refactoring the code for open source. More information and detailed usage will be made available soon.

Advantages

Isolation and Multi-Tenant: With ALB operator, multiple ALB instances can be created and managed in one cluster. Each tenant can has a group of dedicated ALB instances.
Ingress and Gateway API Support: Users can flexibly choose between Ingress and Gateway API according to their own preferences.
Flexible User Defined Traffic Rule: ALB provides a traffic rule DSL that can support more complex traffic matching and distribution scenarios that beyond the capabilities of standard Ingress and Gateway API.
Multiple Protocol Support: ALB can manage HTTP, HTTPS, TCP and UDP traffic.

Architecture

Quick Start

Deploy the ALB Operator

Create a kind cluster
helm repo add alb https://alauda.github.io/alb/;helm repo update;helm search repo|grep alb
helm install alb-operator alb/alauda-alb2

Deploy an ALB Instance

cat <<EOF | kubectl apply -f -
apiVersion: crd.alauda.io/v2beta1
kind: ALB2
metadata:
    name: alb-demo
    namespace: kube-system
spec:
    address: "172.20.0.5"  # the ip address of node where alb been deployed
    type: "nginx" 
    config:
        networkMode: host
        loadbalancerName: alb-demo
        projects:
        - ALL_ALL
        replicas: 1
EOF

Rua a Demo Application

cat <<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-world
  labels:
    k8s-app: hello-world
spec:
  replicas: 1 
  selector:
    matchLabels:
      k8s-app: hello-world
  template:
    metadata:
      labels:
        k8s-app: hello-world
    spec:
      terminationGracePeriodSeconds: 60
      containers:
      - name: hello-world
        image: docker.io/crccheck/hello-world:latest 
        imagePullPolicy: IfNotPresent
---
apiVersion: v1
kind: Service
metadata:
  name: hello-world
  labels:
    k8s-app: hello-world
spec:
  ports:
  - name: http
    port: 80
    targetPort: 8000
  selector:
    k8s-app: hello-world 
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: hello-world
spec:
  rules:
  - http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: hello-world
            port:
              number: 80
EOF

Now you visit the app by curl http://${ip}

Advanced Features

`Frontend` and `Rule`

Complex traffic matching and distribution patterns can be configured by Frontend and Rule.
syntax of rule's dslx

apiVersion: crd.alauda.io/v1
kind: Frontend
metadata:
  labels:
    alb2.cpaas.io/name: alb-demo # required, indicate the ALB instance to which this Frontend belongs to
  name: alb-demo-00080
  namespace: kube-system
spec:
  backendProtocol: ""   # http|https 
  certificate_name: ""  # $secret_ns/$secret_name
  port: 80              
  protocol: http        # protocol of this Frontend itself
---
apiVersion: crd.alauda.io/v1
kind: Rule
metadata:
  labels:
    alb2.cpaas.io/frontend: alb-demo-00080  # required, indicate the Frontend to which this rule belongs
    alb2.cpaas.io/name: alb-demo            # required, indicate the ALB to which this rule belongs
  name: alb-demo-00080-test
  namespace: kube-system
spec:
  backendProtocol: ""                       # as same as Frontend
  certificate_name: ""                      # as same as Frontend
  dslx:                                     # this rule matches url starts with /app-a or /app-b and method is post,and url param's group is vip, and host is *.app.com, and header's location is east-1 or east-2 and has a cookie name is uid, and source IPs come from 1.1.1.1-1.1.1.100
  - type: METHOD
    values:
    - - EQ
      - POST
  - type: URL
    values:
    - - STARTS_WITH
      - /app-a
    - - STARTS_WITH
      - /app-b
  - type: PARAM
    key: group
    values:
    - - EQ
      - vip
  - type: HOST 
    values:
    - - ENDS_WITH
      - .app.com
  - type: HEADER
    key: LOCATION 
    values:
    - - IN
      - east-1
      - east-2
  - type: COOKIE
    key: uid
    values:
    - - EXIST 
  - type: SRC_IP
    values:
    - - RANGE
      - "1.1.1.1"
      - "1.1.1.100"
  enableCORS: false
  priority: 5                              # the lower the number, the higher the priority
  serviceGroup:
    services:
    - name: hello-world
      namespace: default
      port: 80
      weight: 100

Ingress Annotations

Rewrite Request

alb.ingress.cpaas.io/rewrite-request: |
{"headers_remove":["h1"],"headers":{"a":"b"},"headers_add":{"aa": ["bb","cc"]}}

headers_remove: remove the header. headers_add: append to the header instead of overwrite it. headers: set the header.

Rewrite Response

alb.ingress.cpaas.io/rewrite-response: |
{"headers_remove":["h1"],"headers":{"a":"b"},"headers_add":{"aa": ["bb","cc"]}}