如何使用Vanish转发流量

Varnish using for new fresh

• What is varnish

  • Varnish is a http cache tool for accelerating http request response.
  • The configuration language of varnish is named as VCL, which can handle the incoming requests
    • decide what content you want to server
    • from where you want to get the content
    • how the request or response should be altered
    • beef-sandwich
      
    • How does it work
      • based on VCL program, it can ‘Which backend has this content, how long time can we cache it, is it accessible for this request, should it be redirected elsewhere and so on’.
      • VCL can be compiled into C-program which is complied into a shared lib. This will happen to varnish loads VCL program.
  • core features
    • caching, using Cache-Control HTTP header
    • Content Composition
    • support many different OS platforms
    • full control of every request

• How to install varnish

  • brew install varnish
  • sudo mv /usr/local/opt/varnish/sbin/varnishd /usr/local/bin/
  • then varnishd can be executed directly

• How to use varnish

  • in local

    • add default.vcl file
    • run the following cmd varnishd -a :6081,HTTP -f default.vcl -F
      • -a listening port
      • -f configuration file location
      • -F run varnish in the front
    • call the 127.0.0.1/api/public for testing

  • by docker

    • use docker cmd directly

      docker run --rm -v $(PWD)/default-docker.vcl:/etc/varnish/default.vcl:ro \  
          --tmpfs /var/lib/varnish/varnishd:exec \
          --name my-varnish-container \
          -p 8081:80 \
          -e VARNISH_SIZE=2G \
          varnish

      • varnish proxy the local machine service, the host of vcl should be set as “docker.mac.for.localhost”.
      • tips:
        • varnish port in docker is 80

    • use docker file

      • create a docker file

      • mount the vcl file into your custom image

      • run your custom image

        docker run -it --tmpfs /var/lib/varnish/varnishd:exec -p 8081:80 local-varnish

    • docker-compose

  • in local k8s

    • create k8s configMap for mounting default.vcl

    kubectl create configmap varnish-vcl --from-file=default.vcl

    • deploy

    kubectl apply -f deployment/deployment.yaml

    • call api

    http://localhost:6081/api/public

    {
      "message": "All good. You DO NOT need to be authenticated to call /api/public."
    }

    • validate

      • step1

        kubectl exec -it varnish-proxy-5b4844596c-22hsl -c varnish-for-be -- sh

      • step2
        run varnishlog
        

    • issue:

      • if not define the Type in service yaml, it will use the default value ClusterIP
      • Solution: add type: NodePort under spec section

varnish