k8s crd services

README.md

Purpose

This gist contains examples of yaml configurations for the service load balancing in the k8s crd provider.

Goal

The goal is to expose:

• a "user friendly" configuration (with potentialy complex usecases)
• avoid confusion between K8s native objects and Traefik one
• avoid to break the current configuration

Context

The mirror and weighted services can use any combination of any kind of services as child (serverLB, wrr, mirror). We have to manage different types of objects that could be internal (traefik crd) or external (native k8s objects). The basic usage should stay easy to use.

Naming

All names could be change such as:

• serviceName attribute that refers to a NodeService name
• NodeService name of the CRD that defines a traefik service
• nodeServices name of the list of traefik services

Usage

The samples have the following naming convention: <solution>_<usecase>.yaml

Solutions

serviceName Switch

Switch between two exclusives attributes:

• name -> k8s services
• serviceName -> traefik nodeService

It is the actual solution available in the PR

2 Distinct Lists

To avoid confusion between Traefik and K8s services, we can separe those 2 types of services in 2 distinct lists. The list could be under the actual service list but it would be breaking. Otherwise we can add a list at the same level of the existing one. We have to apply it both for mirroring and wrr. As we just use a name, we need to specify a specific object for the main service in the mirroring.

Provider Namespace

As Traefik use provider namespace to manage cross provider configuration, we may force the annotation to define if the service used is a Traefik (with namespace) or a K8s one (without namespace or with a specific one ?).

No explicit k8s service. (breaking).

This change would break the existing configuration schema. A service referenced by the "name" attribute is always a nodeService, so there's never any conflict with a reference to a k8s service. When we actually need to create a load-balancer of servers we wrap a k8s service within e.g. a traefik service wrr.

disctincLists_basic.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    # k8s services
    services:
      - name: whoami4
        percent: 50
        port: 8080
    # Traefik services
    nodeServices:
      - name: wrr1

disctincLists_complex.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: v1
kind: Service
metadata:
  name: whoami4
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami4

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr2
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: mirror1
  namespace: default

spec:
  mirroring:
    # We need to define if the "main" service is a traefik or k8s one

    # k8s main service
    service:
      name: whoami5
      port: 8080

# Alternative with a Traefik service
#    nodeService:
#      name: wrr2

    mirrors:
      services:
        - name: whoami4
          percent: 50
          port: 8080
      nodeServices:
        - name: wrr2
          percent: 40

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080
    nodeServices:
      - name: wrr2
        weight: 1
      - name: mirror1
        weight: 1

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    # k8s services
    services:
    - name: whoami4
      port: 8080
    # Traefik services
    nodeServices:
    - name: wrr1

providerNamespace_basic.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    services:
    - name: wrr1@kubernetescrd
    - name: whoami5
      port: 8080

providerNamespace_complex.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: v1
kind: Service
metadata:
  name: whoami4
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami4

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr2
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080
      - name: wrr2@kubernetescrd

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: mirror1
  namespace: default

spec:
  mirroring:
    name: whoami5
    port: 8080

# Alternative with a Traefik service
#   name: wrr2@kubernetescrd

    mirrors:
      - name: whoami4
        percent: 50
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - name: wrr2@kubernetescrd
        weight: 1
      - name: whoami5
        weight: 1
        port: 8080
      - name: mirror1@kubernetescrd
        weight: 1

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    services:
    - name: wrr1@kubernetescrd
    - name: whoami4
      percent: 50
      port: 8080

serviceName_basic.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    services:
    - serviceName: wrr1
    - name: whoami5
      port: 8080

serviceName_complex.yml

---
apiVersion: v1
kind: Service
metadata:
  name: whoami5
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami5

---
apiVersion: v1
kind: Service
metadata:
  name: whoami4
  namespace: default

spec:
  ports:
    - name: web
      port: 8080
  selector:
    app: containous
    task: whoami4

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr2
  namespace: default

spec:
  weighted:
    services:
      - name: whoami5
        weight: 1
        port: 8080

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: mirror1
  namespace: default

spec:
  mirroring:
    name: whoami5
    port: 8080

# Alternative with a Traefik service
#   serviceName: wrr2

    mirrors:
      - name: whoami4
        percent: 50
        port: 8080
      - serviceName: wrr2

---
apiVersion: traefik.containo.us/v1alpha1
kind: NodeService
metadata:
  name: wrr1
  namespace: default

spec:
  weighted:
    services:
      - serviceName: wrr2
        weight: 1
      - name: whoami5
        weight: 1
        port: 8080
      - serviceName: mirror1
        weight: 1

---
apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: test.route
  namespace: default

spec:
  entryPoints:
    - web

  routes:
  - match: Host(`foo.com`) && PathPrefix(`/foo`)
    kind: Rule
    priority: 12
    services:
    - serviceName: wrr1
    - name: whoami4
      port: 8080