Merge pull request #2 from miun173/release

feature: add round robin load balancer

.chglog/CHANGELOG.tpl.md

@@ -0,0 +1,41 @@
+{{ if .Versions -}}
+<a name="unreleased"></a>
+
+{{ if .Unreleased.CommitGroups -}}
+{{ range .Unreleased.CommitGroups -}}
+### {{ .Title }}
+{{ range .Commits -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{ end }}
+{{ end -}}
+{{ end -}}
+{{ end -}}
+
+{{ range .Versions }}
+<a name="{{ .Tag.Name }}"></a>
+## {{ if .Tag.Previous }}[{{ .Tag.Name }}]{{ else }}{{ .Tag.Name }}{{ end }} - {{ datetime "2006-01-02" .Tag.Date }}
+{{ range .CommitGroups -}}
+### {{ .Title }}
+{{ range .Commits -}}
+- {{ if .Scope }}**{{ .Scope }}:** {{ end }}{{ .Subject }}
+{{ end }}
+{{ end -}}
+
+{{- if .NoteGroups -}}
+{{ range .NoteGroups -}}
+### {{ .Title }}
+{{ range .Notes }}
+{{ .Body }}
+{{ end }}
+{{ end -}}
+{{ end -}}
+{{ end -}}
+
+{{- if .Versions }}
+[Unreleased]: {{ .Info.RepositoryURL }}/compare/{{ $latest := index .Versions 0 }}{{ $latest.Tag.Name }}...HEAD
+{{ range .Versions -}}
+{{ if .Tag.Previous -}}
+[{{ .Tag.Name }}]: {{ $.Info.RepositoryURL }}/compare/{{ .Tag.Previous.Name }}...{{ .Tag.Name }}
+{{ end -}}
+{{ end -}}
+{{ end -}}

.chglog/config.yml

@@ -0,0 +1,27 @@
+style: github
+template: CHANGELOG.tpl.md
+info:
+  title: CHANGELOG
+  repository_url: https://github.com/miun173/rebalance
+options:
+  commits:
+    # filters:
+    #   Type:
+    #     - feat
+    #     - fix
+    #     - perf
+    #     - refactor
+  commit_groups:
+    # title_maps:
+    #   feat: Features
+    #   fix: Bug Fixes
+    #   perf: Performance Improvements
+    #   refactor: Code Refactoring
+  header:
+    pattern: "^(\\w*)\\:\\s(.*)$"
+    pattern_maps:
+      - Type
+      - Subject
+  notes:
+    keywords:
+      - BREAKING CHANGE

.gitignore

@@ -1 +1,2 @@
-/.vscode
+/.vscode
+/output

CHANGELOG.md

@@ -0,0 +1,10 @@
+<a name="unreleased"></a>
+
+
+<a name="v0.1.0"></a>
+## v0.1.0 - 2019-12-27
+### Feature
+- add round robin load balancer
+
+
+[Unreleased]: https://github.com/miun173/rebalance/compare/v0.1.0...HEAD

Makefile

@@ -1,5 +1,24 @@
+bench_cmd := go test -run=^$ github.com/miun173/rebalance/${package} -bench=.
+run_cmd := go run cmd/*
+
+test:
+	go test -v -covermode=atomic ./...
+
 run-proxy:
-	@go run cmd/proxy/main.go
+	@$(run_cmd) proxy
 
 run-sidecar:
-	@go run cmd/sidecar/main.go $(args)
+	@$(run_cmd) sidecar join --url $(url) --service-ports $(service-ports)
+
+build:
+	@go build -ldflags="-w -s" -o output/rebalance ./cmd/...
+
+bench:
+	@cd proxy && $(bench_cmd)
+
+changelog:
+ifdef version
+	@git-chglog --next-tag $(version) -o CHANGELOG.md
+else
+	@git-chglog -o CHANGELOG.md
+endif

README.md

@@ -3,6 +3,23 @@
 Experimentation on server load balancing using Round Robin algorithm with self join.
 
 ## TODO
-- [ ] proxy request to several ip
-    - [?] proxy request to an ip
-- [ ] add self join & discovery
+- [x] proxy request to several ip
+    - [x] proxy request to an ip
+- [ ] add self join & discovery
+    - [x] can join from proxied services
+- [x] handle concurrent proxy requests
+    - [reff](https://kasvith.github.io/posts/lets-create-a-simple-lb-go)
+
+# Benchmarks
+`$ make bench package=proxy`
+```
+goos: linux
+goarch: amd64
+pkg: github.com/miun173/rebalance/proxy
+Benchmark4Upstream/200_microsecond/response/1000_req-4              1000000000          0.87 ns/op
+Benchmark4Upstream/200_microsecond/response/10000_req-4             1                   8659798397 ns/op
+Benchmark4Upstream/20_microsecond/response/1000_req-4               1000000000          0.87 ns/op
+Benchmark4Upstream/20_microsecond/response/10000_req-4              1                   8673090255 ns/op
+PASS
+ok      github.com/miun173/rebalance/proxy      79.571s
+```

cmd/main.go

@@ -0,0 +1,5 @@
+package main
+
+func main() {
+	rootCMD.Execute()
+}

cmd/root.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+
+	"github.com/miun173/rebalance/proxy"
+	"github.com/miun173/rebalance/sidecar"
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+var (
+	// used for flags
+	url          string
+	servicePorts string
+
+	rootCMD  = &cobra.Command{}
+	proxyCMD = &cobra.Command{
+		Use:   "proxy",
+		Short: "a reverse proxy",
+		Run:   runProxy,
+	}
+
+	sidecarCMD = &cobra.Command{
+		Use:   "sidecar",
+		Short: "a sidecar proxy",
+	}
+
+	joinCMD = &cobra.Command{
+		Use:     "join",
+		Short:   "join a service into proxy",
+		Example: "join --url 'http://127.0.0.1:9000'",
+		Run:     runJoinProxy,
+	}
+)
+
+func init() {
+	joinCMD.PersistentFlags().StringVar(&url, "url", "", "proxy service url")
+	joinCMD.PersistentFlags().StringVar(&servicePorts, "service-ports", "80", "services ports that will be proxied 80,8080,9000")
+
+	sidecarCMD.AddCommand(joinCMD)
+	rootCMD.AddCommand(sidecarCMD)
+	rootCMD.AddCommand(proxyCMD)
+}
+
+func runProxy(cmd *cobra.Command, args []string) {
+	fmt.Println("starting loadbalancer at :9000")
+
+	sp := proxy.NewServiceProxy()
+
+	signalCh := make(chan os.Signal, 1)
+	defer close(signalCh)
+
+	signal.Notify(signalCh, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
+
+	go sp.Start()
+	go sp.RunHealthCheck()
+
+	<-signalCh
+	log.Println("exiting...")
+}
+
+func runJoinProxy(cmd *cobra.Command, args []string) {
+	if url == "" {
+		log.Fatal(errors.New("url should be in form 'http://127.0.0.1:9000'"))
+	}
+
+	ports := strings.Split(servicePorts, ",")
+	sc := sidecar.NewSideCar(url)
+	if err := sc.Join(ports...); err != nil {
+		log.Fatal(err)
+	}
+}

go.mod

@@ -1,3 +1,9 @@
 module github.com/miun173/rebalance
 
 go 1.12
+
+require (
+	github.com/sirupsen/logrus v1.4.2
+	github.com/spf13/cobra v0.0.5
+	github.com/stretchr/testify v1.4.0
+)

go.sum

@@ -0,0 +1,57 @@
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proxy/service.go

@@ -0,0 +1,39 @@
+package proxy
+
+import (
+	"net/http/httputil"
+	"net/url"
+	"sync"
+)
+
+// Service :nodoc:
+type Service struct {
+	Proxy   *httputil.ReverseProxy
+	URL     *url.URL
+	isAlive bool
+	mutex   sync.RWMutex
+}
+
+// NewService :nodoc:
+func NewService(p *httputil.ReverseProxy, u *url.URL) *Service {
+	return &Service{
+		Proxy:   p,
+		URL:     u,
+		isAlive: true,
+	}
+}
+
+// SetAlive :nodoc:
+func (s *Service) SetAlive(alive bool) {
+	s.mutex.Lock()
+	s.isAlive = alive
+	s.mutex.Unlock()
+}
+
+// IsAlive :nodoc:
+func (s *Service) IsAlive() (alive bool) {
+	s.mutex.Lock()
+	alive = s.isAlive
+	s.mutex.Unlock()
+	return
+}