Go - Rafting
A framework to build clusters using the hashicorp's raft implementation.
Install
go get -u github.com/danielgatis/go-rafting
And then import the package in your code:
import "github.com/danielgatis/go-rafting"
Usage
Create a new app state with some commands:
state := rafting.NewState(make(map[string]string))
state.Command("set", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
val := cast.ToString(args["val"])
d[key] = val
return val, nil
})
state.Command("get", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
return d[key], nil
})
state.Command("del", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
value := d[key]
delete(d, key)
return value, nil
})
Create a new raft node with a mdns discovery:
node, err := rafting.NewNode(rid, state.FSM(), rport, rafting.WithMdnsDiscovery())
if err != nil {
logrus.Fatal(err)
}
Starting the node:
node.Start(context.Background())
Thats it!
Example
The example bellow is the code for the banner video.
package main
import (
"context"
"flag"
"fmt"
"time"
"github.com/danielgatis/go-ctrlc"
"github.com/danielgatis/go-rafting"
"github.com/gofiber/fiber/v2"
"github.com/sirupsen/logrus"
"github.com/spf13/cast"
)
var (
rid string
rport int
hport int
)
func init() {
flag.StringVar(&rid, "rid", "1", "raft node id")
flag.IntVar(&rport, "rport", 4001, "raft port number")
flag.IntVar(&hport, "hport", 3001, "http port number")
}
func main() {
flag.Parse()
// raft node
state := rafting.NewState(make(map[string]string))
node, err := rafting.NewNode(rid, state.FSM(), rport, rafting.WithMdnsDiscovery())
if err != nil {
logrus.Fatal(err)
}
state.Command("set", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
val := cast.ToString(args["val"])
d[key] = val
return val, nil
})
state.Command("get", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
return d[key], nil
})
state.Command("del", func(data interface{}, args map[string]interface{}) (interface{}, error) {
d := data.(map[string]string)
key := cast.ToString(args["key"])
value := d[key]
delete(d, key)
return value, nil
})
ctx, cancel := context.WithCancel(context.Background())
go func() { logrus.Fatal(node.Start(ctx)) }()
// http server
app := fiber.New()
app.Get("/:op/:key/:val?", func(c *fiber.Ctx) error {
result, err := node.Apply(c.Params("op"), time.Second, "key", c.Params("key"), "val", c.Params("val"))
if err != nil {
return err
}
return c.SendString(cast.ToString(result))
})
go func() { logrus.Fatal(app.Listen(fmt.Sprintf(":%d", hport))) }()
// waiting
ctrlc.Watch(func() {
cancel()
app.Shutdown()
})
<-ctx.Done()
}
License
Copyright (c) 2021-present Daniel Gatis
Licensed under MIT License
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