A minor refactor (removed all logging for now)

freighter.go

@@ -1,11 +1,11 @@
 package freighter
 
 import (
+	"net/http"
 	"net/url"
 	"sync"
 	"time"
 
-	"github.com/ShardulNalegave/freighter/balancer"
 	"github.com/ShardulNalegave/freighter/pool"
 	"github.com/ShardulNalegave/freighter/strategy"
 )
@@ -18,33 +18,35 @@ type Options struct {
 }
 
 type Freighter struct {
-	p                   *pool.ServerPool
-	b                   *balancer.Balancer
+	URL                 *url.URL
+	pl                  *pool.ServerPool
+	Strategy            strategy.Strategy
 	healthCheckInterval time.Duration
 }
 
-func (f *Freighter) ListenAndServe() {
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go f.b.ListenAndServe(&wg)
-	go HealthCheck(f.p, f.healthCheckInterval)
-	wg.Wait()
+func (f *Freighter) ListenAndServe(wg *sync.WaitGroup) {
+	defer wg.Done()
+	go HealthCheck(f.pl, f.healthCheckInterval)
+	http.ListenAndServe(f.URL.Host, http.HandlerFunc(f.Handle))
 }
 
-func NewFreighter(opts *Options) *Freighter {
-	p := &pool.ServerPool{
-		Backends: opts.Backends,
+func (f *Freighter) Handle(w http.ResponseWriter, r *http.Request) {
+	if backend := f.Strategy.Handle(r, f.pl); backend != nil {
+		backend.ReverseProxy.ServeHTTP(w, r)
+	} else {
+		http.Error(w, "Service unavailable", http.StatusServiceUnavailable)
 	}
+}
 
-	b := &balancer.Balancer{
-		URL:      opts.URL,
-		Pool:     p,
-		Strategy: opts.Strategy,
+func NewFreighter(opts *Options) *Freighter {
+	pl := &pool.ServerPool{
+		Backends: opts.Backends,
 	}
 
 	return &Freighter{
-		p:                   p,
-		b:                   b,
+		URL:                 opts.URL,
+		Strategy:            opts.Strategy,
+		pl:                  pl,
 		healthCheckInterval: opts.HealthCheckInterval,
 	}
 }

go.mod

@@ -2,13 +2,4 @@ module github.com/ShardulNalegave/freighter
 
 go 1.21.6
 
-require (
-	github.com/google/uuid v1.6.0
-	github.com/rs/zerolog v1.32.0
-)
-
-require (
-	github.com/mattn/go-colorable v0.1.13 // indirect
-	github.com/mattn/go-isatty v0.0.20 // indirect
-	golang.org/x/sys v0.17.0 // indirect
-)
+require github.com/google/uuid v1.6.0

go.sum

@@ -1,34 +1,2 @@
-github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
-github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
-github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
-github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
-github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/pelletier/go-toml/v2 v2.1.1 h1:LWAJwfNvjQZCFIDKWYQaM62NcYeYViCmWIwmOStowAI=
-github.com/pelletier/go-toml/v2 v2.1.1/go.mod h1:tJU2Z3ZkXwnxa4DPO899bsyIoywizdUvyaeZurnPPDc=
-github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
-github.com/rs/zerolog v1.32.0 h1:keLypqrlIjaFsbmJOBdB/qvyF8KEtCWHwobLp5l/mQ0=
-github.com/rs/zerolog v1.32.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.17.0 h1:25cE3gD+tdBA7lp7QfhuV+rJiE9YXTcS3VG1SqssI/Y=
-golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

health.go

@@ -4,13 +4,11 @@ import (
 	"time"
 
 	"github.com/ShardulNalegave/freighter/pool"
-	"github.com/rs/zerolog/log"
 )
 
 func HealthCheck(p *pool.ServerPool, interval time.Duration) {
 	t := time.NewTicker(interval)
 	for range t.C {
-		log.Info().Msg("Running periodic Health-Check")
 		p.CheckHealth()
 	}
 }

pool/backend.go

@@ -8,36 +8,38 @@ import (
 	"time"
 
 	"github.com/google/uuid"
-	"github.com/rs/zerolog/log"
 )
 
+// Backend is representation of an actual running backend.
 type Backend struct {
 	ID           string
-	Metadata     map[string]interface{}
+	Metadata     interface{} // Metadata to be set by user
 	URL          *url.URL
 	alive        bool
 	mutex        sync.RWMutex
 	ReverseProxy *httputil.ReverseProxy
 }
 
+// Returns the alive status of backend
 func (b *Backend) IsAlive() bool {
 	b.mutex.RLock()
 	alive := b.alive
 	b.mutex.RUnlock()
 	return alive
 }
 
+// Sets the alive status of backend
 func (b *Backend) SetAlive(alive bool) {
 	b.mutex.Lock()
 	b.alive = alive
 	b.mutex.Unlock()
 }
 
+// Checks backend health and update alive status accordingly
 func (b *Backend) CheckHealth() {
 	timeout := 2 * time.Second
 	conn, err := net.DialTimeout("tcp", b.URL.Host, timeout)
 	if err != nil {
-		log.Error().Str("URL", b.URL.Host).Msg("Backend not responding")
 		b.SetAlive(false)
 		return
 	}
@@ -46,11 +48,12 @@ func (b *Backend) CheckHealth() {
 	b.SetAlive(true)
 }
 
+// Constructs a new backend instance
 func NewBackend(URL *url.URL, meta interface{}) *Backend {
 	rp := httputil.NewSingleHostReverseProxy(URL)
 	return &Backend{
 		ID:           uuid.NewString(),
-		Metadata:     make(map[string]interface{}),
+		Metadata:     meta,
 		URL:          URL,
 		ReverseProxy: rp,
 		alive:        true,

pool/pool.go

@@ -1,9 +1,11 @@
 package pool
 
+// Server-Pool of all registered backends
 type ServerPool struct {
 	Backends []*Backend
 }
 
+// Checks health of all backends
 func (sp *ServerPool) CheckHealth() {
 	for _, b := range sp.Backends {
 		b.CheckHealth()

strategy/roundRobin.go

@@ -23,6 +23,7 @@ func (rr *RoundRobin) Handle(r *http.Request, p *pool.ServerPool) *pool.Backend
 			return p.Backends[index]
 		}
 	}
+
 	return nil
 }
 

test/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"net/url"
+	"sync"
+	"time"
+
+	"github.com/ShardulNalegave/freighter"
+	"github.com/ShardulNalegave/freighter/pool"
+	"github.com/ShardulNalegave/freighter/strategy"
+)
+
+func main() {
+	srv := freighter.NewFreighter(&freighter.Options{
+		URL: &url.URL{
+			Host: ":5000",
+		},
+		HealthCheckInterval: time.Second * 5,
+		Strategy:            &strategy.RoundRobin{},
+		Backends: []*pool.Backend{
+			pool.NewBackend(&url.URL{Host: ":8080", Scheme: "http"}, nil),
+		},
+	})
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	go srv.ListenAndServe(&wg)
+
+	wg.Wait()
+}