Developer Guide on Apache Dubbo

Filter Overview

Mon, 01 Jan 0001 00:00:00 +0000

Filter

Filter provides request handle abstraction. User can combinate many filters together into filter-chain.

When receiving request from the listener, filter will handle it one by one at its pre or post phase.

Because pixiu want to provide network protocol transform function, so the filter contains network filter and the filter below network filter such as http filter.

the request processing order is as follows.

client -> listner -> network filter such as httpconnectionmanager -> http filter chain

You can find out all filters in pkg/filter. Just list some filters as the following.

Introduction to the Pixiu Filter System

Mon, 01 Jan 0001 00:00:00 +0000

How to Write a Filter

For more detailed information, please refer to the Blog "Talking About Pixiu's Filter"

Let’s try writing a simple Filter that will have a basic configuration, log the request Body during the Decode phase, and return the reversed string as a Mock response. Finally, in the Encode phase, it will log the return value based on the configuration.

First, create a Filter

type DemoFilter struct {
 logPrefix string
}

// Decode phase, occurs before calling Upstream
func (f *DemoFilter) Decode(ctx *contexthttp.HttpContext) filter.FilterStatus {
 body, _ := ioutil.ReadAll(ctx.Request.Body)
 logger.Infof("request body: %s", body)

 //reverse res str
 runes := []rune(string(body))
 for i := 0; i < len(runes)/2; i += 1 {
 runes[i], runes[len(runes)-1-i] = runes[len(runes)-1-i], runes[i]
 }
 reverse := string(runes)

 //mock response
 ctx.SendLocalReply(200, []byte(reverse))
 return filter.Stop
}

// Encode phase, at this point the Upstream Response can be accessed
func (f *DemoFilter) Encode(ctx *contexthttp.HttpContext) filter.FilterStatus {
 res := ctx.SourceResp.(string)
 logger.Infof("%s: %s", f.logPrefix, res)
 return filter.Continue
}

Create a Filter Factory

type (
	DemoFilterFactory struct {
		conf *Config
	}
	// Config describe the config of Filter
	Config struct {
		LogPrefix string `yaml:"logPrefix,omitempty"`
	}
)

func (f *DemoFilterFactory) PrepareFilterChain(ctx *contexthttp.HttpContext, chain filter.FilterChain) error {
 demo := &DemoFilter{logPrefix: f.conf.LogPrefix}

 chain.AppendDecodeFilters(demo)
 chain.AppendEncodeFilters(demo)
 return nil
}

func (f *DemoFilterFactory) Config() interface{} {
 return f.conf
}

func (f *DemoFilterFactory) Apply() error {
 return nil
}

Create a Filter Plugin and register it

//important
func init() {
 filter.RegisterHttpFilter(&Plugin{})
}

type Plugin struct {
}

func (p *Plugin) Kind() string {
 return "dgp.filters.demo"
}

func (p *Plugin) CreateFilterFactory() (filter.HttpFilterFactory, error) {
	return &DemoFilterFactory{conf: &Config{}}, nil
}

Configure this Filter in the configuration file and start Pixiu

static_resources:
 listeners:
 - name: "net/http"
 protocol_type: "HTTP"
 address:
 socket_address:
 address: "0.0.0.0"
 port: 8888
 filter_chains:
 filters:
 - name: dgp.filter.httpconnectionmanager
 config:
 route_config:
 routes:
 - match:
 prefix: "/"
 http_filters:
 - name: dgp.filters.demo
 config:

Access and check the logs and results

curl localhost:8888/demo -d "eiv al tse’c"

c’est la vie%

Logs

dubbo-pilot Control Plane Deployment

Mon, 01 Jan 0001 00:00:00 +0000

1 Overall Goals

Compile the control plane and build images
Deploy using istioctl in a Kubernetes environment
How to debug the control plane program

2 Basic Process

This example will demonstrate how to compile the dubbo-pilot control plane and how to deploy it using istioctl in a Kubernetes environment.

Start the control plane locally, and debug dubbo-pilot.
Use istioctl for starting and debugging in the k8s environment.

3 Detailed Steps

3.1 Environment Requirements

Golang
Docker
Minikube/Kind
Kubectl
Dlv

3.2 Local Deployment

3.2.1 Compilation

Compile the docker-builder

cd dubbo-go-pixiu/tools/docker-builder && go install

docker-builder -h:

Builds Istio docker images

Usage:
 [flags]

Flags:
 --architecures strings architectures to build (default [linux/amd64])
 --base-version string base version to use (default "latest")
 --builder string type of builder to use. options are crane or docker (default "docker")
 -h, --help help for this command
 --hub strings docker hub(s) (default [localhost:5000])
 --istio-version string istio version to use (default "1.14-dev")
 --kind-load kind cluster to load into
 --no-cache disable caching
 --no-clobber do not allow pushing images that already exist
 --proxy-version string proxy version to use (default "7ae8e27f274b33dc2f4d83100aea5971ed6698d3")
 --push push targets to registry
 --save save targets to tar.gz
 --tag strings docker tag(s) (default [latest])
 --targets strings targets to build (default [app,app_sidecar_centos_7,app_sidecar_debian_11,app_sidecar_ubuntu_jammy,app_sidecar_ubuntu_xenial,ext-authz,install-cni,istioctl,operator,pilot,proxyv2])
 --variants strings variants to build (default [default])
 --version show build version

Use docker-builder to automatically compile and build the image

Compile istioctl

Introduction to Trie Prefix Tree

Mon, 01 Jan 0001 00:00:00 +0000

Introduction

One of the cores of the gateway is the routing logic, which determines how a request needs to be processed and which downstream service it should be forwarded to.
About 80% of routing requirements are URL-based. It is necessary to clearly describe how URLs or sets of URLs with certain characteristics correspond to a series of downstream processing strategies.

For example, URLs starting with ‘/test/’ route to the testing environment cluster, while URLs starting with ‘/release/user/’ route to the production environment’s user services cluster.

Log Overview

Mon, 01 Jan 0001 00:00:00 +0000

Log

How to view logs in dubbo-go-pixiu.

DEBUG log

Dubbo request log

2020-11-17T11:31:05.716+0800 DEBUG dubbo/dubbo.go:150 [dubbo-go-pixiu] dubbo invoke, method:GetUserByName, types:[java.lang.String], reqData:[tiecheng]

Dubbo response log

2020-11-17T11:31:05.718+0800 DEBUG dubbo/dubbo.go:160 [dubbo-go-pixiu] dubbo client resp:map[age:88 iD:3213 name:tiecheng time:<nil>]

Developer Guide on Apache Dubbo

Filter Overview

Filter

Http Filter List

Introduction to the Pixiu Filter System

How to Write a Filter

dubbo-pilot Control Plane Deployment

1 Overall Goals

2 Basic Process

3 Detailed Steps

3.1 Environment Requirements

3.2 Local Deployment

3.2.1 Compilation

Introduction to Trie Prefix Tree

Introduction

Log Overview

Log

DEBUG log

Dubbo request log

Dubbo response log