config-local (This is a community driven project)

中文

Read, load, and listen to local configuration files

Usage

Basic

Server

package main

import (
	"context"
	"log"

	"github.com/cloudwego/kitex-examples/kitex_gen/api"
	"github.com/cloudwego/kitex-examples/kitex_gen/api/echo"
	"github.com/cloudwego/kitex/pkg/klog"
	"github.com/cloudwego/kitex/pkg/rpcinfo"
	kitexserver "github.com/cloudwego/kitex/server"
	"github.com/kitex-contrib/config-file/filewatcher"
	fileserver "github.com/kitex-contrib/config-file/server"
)

var _ api.Echo = &EchoImpl{}

const (
	filepath    = "kitex_server.json"
	key         = "ServiceName"
	serviceName = "ServiceName"
)

// EchoImpl implements the last service interface defined in the IDL.
type EchoImpl struct{}

// Echo implements the Echo interface.
func (s *EchoImpl) Echo(ctx context.Context, req *api.Request) (resp *api.Response, err error) {
	klog.Info("echo called")
	return &api.Response{Message: req.Message}, nil
}

func main() {
	klog.SetLevel(klog.LevelDebug)

	// create a file watcher object
	fw, err := filewatcher.NewFileWatcher(filepath)
	if err != nil {
		panic(err)
	}
	// start watching file changes
	if err = fw.StartWatching(); err != nil {
		panic(err)
	}
	defer fw.StopWatching()

	svr := echo.NewServer(
		new(EchoImpl),
		kitexserver.WithServerBasicInfo(&rpcinfo.EndpointBasicInfo{ServiceName: serviceName}),
		kitexserver.WithSuite(fileserver.NewSuite(key, fw)), // add watcher
	)
	if err := svr.Run(); err != nil {
		log.Println("server stopped with error:", err)
	} else {
		log.Println("server stopped")
	}
}

Client

package main

import (
	"context"
	"log"
	"os"
	"os/signal"
	"time"

	"github.com/cloudwego/kitex-examples/kitex_gen/api"
	"github.com/cloudwego/kitex-examples/kitex_gen/api/echo"
	kitexclient "github.com/cloudwego/kitex/client"
	"github.com/cloudwego/kitex/pkg/klog"
	fileclient "github.com/kitex-contrib/config-file/client"
	"github.com/kitex-contrib/config-file/filewatcher"
)

const (
	filepath    = "kitex_client.json"
	key         = "ClientName/ServiceName"
	serviceName = "ServiceName"
	clientName  = "ClientName"
)

func main() {
	klog.SetLevel(klog.LevelDebug)

	// create a file watcher object
	fw, err := filewatcher.NewFileWatcher(filepath)
	if err != nil {
		panic(err)
	}
	// start watching file changes
	if err = fw.StartWatching(); err != nil {
		panic(err)
	}

	go func() {
		sig := make(chan os.Signal, 1)
		signal.Notify(sig, os.Interrupt, os.Kill)
		<-sig
		fw.StopWatching()
		os.Exit(1)
	}()

	client, err := echo.NewClient(
		serviceName,
		kitexclient.WithHostPorts("0.0.0.0:8888"),
		kitexclient.WithSuite(fileclient.NewSuite(serviceName, key, fw)),
	)
	if err != nil {
		log.Fatal(err)
	}

	for {
		req := &api.Request{Message: "my request"}
		resp, err := client.Echo(context.Background(), req)
		if err != nil {
			klog.Errorf("take request error: %v", err)
		} else {
			klog.Infof("receive response %v", resp)
		}
		time.Sleep(time.Second * 10)
	}
}

Governance Policy

The service name is ServiceName and the client name is ClientName.

Rate Limit Category=limit

Currently, current limiting only supports the server side, so ClientServiceName is empty.

JSON Schema

Variable	Introduction
connection_limit	Maximum concurrent connections
qps_limit	Maximum request number every 100ms

Example:

{
    "ServiceName": {
        "limit": {
            "connection_limit": 300,
            "qps_limit": 200
        }
    }
}

Note:

• The granularity of the current limit configuration is server global, regardless of client or method.
• Not configured or value is 0 means not enabled.
• connection_limit and qps_limit can be configured independently, e.g. connection_limit = 100, qps_limit = 0

Retry Policy Category=retry

JSON Schema

Variable	Introduction
type	0: failure_policy 1: backup_policy
failure_policy.backoff_policy	Can only be set one of fixed none random

Example：

{
    "ClientName/ServiceName": {
        "retry": {
            "*": {
                "enable": true,
                "type": 0,
                "failure_policy": {
                    "stop_policy": {
                        "max_retry_times": 3,
                        "max_duration_ms": 2000,
                        "cb_policy": {
                            "error_rate": 0.2
                        }
                    }
                }
            },
            "Echo": {
                "enable": true,
                "type": 1,
                "backup_policy": {
                    "retry_delay_ms": 200,
                    "stop_policy": {
                        "max_retry_times": 2,
                        "max_duration_ms": 1000,
                        "cb_policy": {
                            "error_rate": 0.3
                        }
                    }
                }
            }
        }
    }
}

Note: retry.Container has built-in support for specifying the default configuration using the * wildcard (see the getRetryer method for details).

RPC Timeout Category=rpc_timeout

JSON Schema

Example：

{
    "ClientName/ServiceName": {
        "timeout": {
            "*": {
                "conn_timeout_ms": 100,
                "rpc_timeout_ms": 2000
            },
            "Pay": {
                "conn_timeout_ms": 50,
                "rpc_timeout_ms": 1000
            }
        },
    }
}

Circuit Break: Category=circuit_break

JSON Schema

Variable	Introduction
min_sample	Minimum statistical sample number

The echo method uses the following configuration (0.3, 100) and other methods use the global default configuration (0.5, 200)

Example：

{
    "ClientName/ServiceName": {
        "circuitbreaker": {
            "Echo": {
                "enable": true,
                "err_rate": 0.3,
                "min_sample": 100
            }
        },
    }
}

Note: The circuit breaker implementation of kitex does not currently support changing the global default configuration (see initServiceCB for details).

More Info

Refer to example for more usage.

Note

For client configuration, you should write all their configurations in the same pair of $UserServiceName/$ServerServiceName, for example

{
    "ClientName/ServiceName": {
        "timeout": {
            "*": {
                "conn_timeout_ms": 100,
                "rpc_timeout_ms": 2000
            },
            "Pay": {
                "conn_timeout_ms": 50,
                "rpc_timeout_ms": 1000
            }
        },
        "circuitbreaker": {
            "Echo": {
                "enable": true,
                "err_rate": 0.3,
                "min_sample": 100
            }
        },
        "retry": {
            "*": {
                "enable": true,
                "type": 0,
                "failure_policy": {
                    "stop_policy": {
                        "max_retry_times": 3,
                        "max_duration_ms": 2000,
                        "cb_policy": {
                            "error_rate": 0.2
                        }
                    }
                }
            },
            "Echo": {
                "enable": true,
                "type": 1,
                "backup_policy": {
                    "retry_delay_ms": 200,
                    "stop_policy": {
                        "max_retry_times": 2,
                        "max_duration_ms": 1000,
                        "cb_policy": {
                            "error_rate": 0.3
                        }
                    }
                }
            }
        }
    }
}