chore(relayer): add HTTP service for health and prometheus metrics

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/cyberhorsey/errors v0.0.0-20220929234051-087d6d8bb841
 	github.com/ethereum/go-ethereum v1.10.25
 	github.com/joho/godotenv v1.4.0
+	github.com/labstack/echo/v4 v4.9.1
 	github.com/pkg/errors v0.9.1
 	github.com/pressly/goose v2.7.0+incompatible
 	github.com/pressly/goose/v3 v3.7.0
@@ -26,8 +27,10 @@ require (
 	github.com/Microsoft/go-winio v0.5.2 // indirect
 	github.com/Microsoft/hcsshim v0.9.4 // indirect
 	github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/btcsuite/btcd/btcec/v2 v2.2.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.1.3 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/containerd/cgroups v1.0.4 // indirect
 	github.com/containerd/containerd v1.6.8 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
@@ -41,13 +44,19 @@ require (
 	github.com/go-sql-driver/mysql v1.6.0 // indirect
 	github.com/go-stack/stack v1.8.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/gorilla/websocket v1.4.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
+	github.com/labstack/echo-contrib v0.13.0 // indirect
+	github.com/labstack/gommon v0.4.0 // indirect
 	github.com/magiconair/properties v1.8.6 // indirect
+	github.com/mattn/go-colorable v0.1.12 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
 	github.com/moby/sys/mount v0.3.3 // indirect
 	github.com/moby/sys/mountinfo v0.6.2 // indirect
 	github.com/moby/term v0.0.0-20220808134915-39b0c02b01ae // indirect
@@ -56,17 +65,25 @@ require (
 	github.com/opencontainers/image-spec v1.0.3-0.20211202183452-c5a74bcca799 // indirect
 	github.com/opencontainers/runc v1.1.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.12.2 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/rjeczalik/notify v0.9.1 // indirect
 	github.com/shirou/gopsutil v3.21.4-0.20210419000835-c7a38de76ee5+incompatible // indirect
 	github.com/tklauser/go-sysconf v0.3.5 // indirect
 	github.com/tklauser/numcpus v0.2.2 // indirect
 	github.com/tyler-smith/go-bip39 v1.1.0 // indirect
+	github.com/valyala/bytebufferpool v1.0.0 // indirect
+	github.com/valyala/fasttemplate v1.2.1 // indirect
 	go.opencensus.io v0.23.0 // indirect
 	golang.org/x/crypto v0.0.0-20220722155217-630584e8d5aa // indirect
 	golang.org/x/net v0.0.0-20220812174116-3211cb980234 // indirect
 	golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab // indirect
+	golang.org/x/text v0.3.7 // indirect
+	golang.org/x/time v0.0.0-20220722155302-e5dcc9cfc0b9 // indirect
 	google.golang.org/genproto v0.0.0-20220617124728-180714bec0ad // indirect
-	google.golang.org/grpc v1.47.0 // indirect
+	google.golang.org/grpc v1.48.0 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

packages/relayer/.default.env

@@ -1,4 +1,5 @@
 HTTP_PORT=4102
+PROMETHEUS_HTTP_PORT=6060
 MYSQL_USER=root
 MYSQL_PASSWORD=root
 MYSQL_DATABASE=relayer
@@ -16,4 +17,5 @@ MYSQL_MAX_OPEN_CONNS=
 MYSQL_CONN_MAX_LIFETIME_IN_MS=
 NUM_GOROUTINES=20
 SUBSCRIPTION_BACKOFF_IN_SECONDS=3
-CONFIRMATIONS_BEFORE_PROCESSING=15
+CONFIRMATIONS_BEFORE_PROCESSING=15
+CORS_ORIGINS=*

packages/relayer/cli/cli.go

@@ -9,13 +9,15 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/labstack/echo/v4"
 
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/joho/godotenv"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 	"github.com/taikochain/taiko-mono/packages/relayer"
 	"github.com/taikochain/taiko-mono/packages/relayer/db"
+	"github.com/taikochain/taiko-mono/packages/relayer/http"
 	"github.com/taikochain/taiko-mono/packages/relayer/indexer"
 	"github.com/taikochain/taiko-mono/packages/relayer/repo"
 	"gorm.io/driver/mysql"
@@ -36,6 +38,7 @@ var (
 		"MYSQL_HOST",
 		"RELAYER_ECDSA_KEY",
 		"CONFIRMATIONS_BEFORE_PROCESSING",
+		"PROMETHEUS_HTTP_PORT",
 	}
 
 	defaultBlockBatchSize      = 2
@@ -77,6 +80,13 @@ func Run(mode relayer.Mode, layer relayer.Layer) {
 		log.Fatal(err)
 	}
 
+	srv, err := http.NewServer(http.NewServerOpts{
+		Echo: echo.New(),
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
 	indexers, closeFunc, err := makeIndexers(layer, db)
 	if err != nil {
 		sqlDB.Close()
@@ -96,6 +106,12 @@ func Run(mode relayer.Mode, layer relayer.Layer) {
 		}(i)
 	}
 
+	go func() {
+		if err := srv.Start(fmt.Sprintf(":%v", os.Getenv("HTTP_PORT"))); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
 	<-forever
 }
 

packages/relayer/http/errors.go

@@ -0,0 +1,14 @@
+package http
+
+import "github.com/cyberhorsey/errors"
+
+var (
+	ErrNoHTTPFramework = errors.Validation.NewWithKeyAndDetail(
+		"ERR_NO_HTTP_ENGINE",
+		"HTTP framework required",
+	)
+	ErrNoRewarder = errors.Validation.NewWithKeyAndDetail(
+		"ERR_NO_REWARDER",
+		"Rewarder is required",
+	)
+)

packages/relayer/http/routes.go

@@ -0,0 +1,5 @@
+package http
+
+func (srv *Server) configureRoutes() {
+	srv.echo.GET("/healthz", srv.Health)
+}

packages/relayer/http/server.go

@@ -0,0 +1,115 @@
+package http
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+
+	"github.com/labstack/echo/v4/middleware"
+
+	echoprom "github.com/labstack/echo-contrib/prometheus"
+	echo "github.com/labstack/echo/v4"
+)
+
+type Server struct {
+	echo *echo.Echo
+}
+
+type NewServerOpts struct {
+	Echo        *echo.Echo
+	CorsOrigins []string
+}
+
+func (opts NewServerOpts) Validate() error {
+	if opts.Echo == nil {
+		return ErrNoHTTPFramework
+	}
+
+	return nil
+}
+
+func NewServer(opts NewServerOpts) (*Server, error) {
+	if err := opts.Validate(); err != nil {
+		return nil, err
+	}
+
+	srv := &Server{
+		echo: opts.Echo,
+	}
+
+	corsOrigins := opts.CorsOrigins
+	if corsOrigins == nil {
+		corsOrigins = []string{"*"}
+	}
+
+	srv.configureMiddleware(corsOrigins)
+
+	return srv, nil
+}
+
+// Start starts the HTTP server
+func (srv *Server) Start(address string) error {
+	return srv.echo.Start(address)
+}
+
+// Shutdown shuts down the HTTP server
+func (srv *Server) Shutdown(ctx context.Context) error {
+	return srv.echo.Shutdown(ctx)
+}
+
+// ServeHTTP implements the `http.Handler` interface which serves HTTP requests
+func (srv *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	srv.echo.ServeHTTP(w, r)
+}
+
+// Health endpoints for probes
+func (srv *Server) Health(c echo.Context) error {
+	return c.NoContent(http.StatusOK)
+}
+
+func LogSkipper(c echo.Context) bool {
+	switch c.Request().URL.Path {
+	case "/healthz":
+		return true
+	case "/metrics":
+		return true
+	default:
+		return false
+	}
+}
+
+func (srv *Server) configureMiddleware(corsOrigins []string) {
+	srv.echo.Use(middleware.RequestID())
+
+	srv.echo.Use(middleware.LoggerWithConfig(middleware.LoggerConfig{
+		Skipper: LogSkipper,
+		Format: `{"time":"${time_rfc3339_nano}","level":"INFO","message":{"id":"${id}","remote_ip":"${remote_ip}",` + //nolint:lll
+			`"host":"${host}","method":"${method}","uri":"${uri}","user_agent":"${user_agent}",` + //nolint:lll
+			`"response_status":${status},"error":"${error}","latency":${latency},"latency_human":"${latency_human}",` +
+			`"bytes_in":${bytes_in},"bytes_out":${bytes_out}}}` + "\n",
+		Output: os.Stdout,
+	}))
+
+	srv.echo.Use(middleware.CORSWithConfig(middleware.CORSConfig{
+		AllowOrigins: corsOrigins,
+		AllowHeaders: []string{echo.HeaderOrigin, echo.HeaderContentType, echo.HeaderAccept},
+		AllowMethods: []string{http.MethodGet, http.MethodHead},
+	}))
+
+	srv.configureAndStartPrometheus()
+
+	srv.configureRoutes()
+}
+
+func (srv *Server) configureAndStartPrometheus() {
+	// Enable metrics middleware
+	p := echoprom.NewPrometheus("echo", nil)
+	p.Use(srv.echo)
+	e := echo.New()
+	p.SetMetricsPath(e)
+
+	go func() {
+		_ = e.Start(fmt.Sprintf(":%v", os.Getenv("PROMETHEUS_HTTP_PORT")))
+	}()
+}

packages/relayer/http/server_test.go

@@ -0,0 +1,97 @@
+package http
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/joho/godotenv"
+	echo "github.com/labstack/echo/v4"
+	"github.com/stretchr/testify/assert"
+)
+
+func newTestServer(url string) *Server {
+	_ = godotenv.Load("../.test.env")
+
+	srv := &Server{
+		echo: echo.New(),
+	}
+
+	srv.configureMiddleware([]string{"*"})
+	srv.configureRoutes()
+	srv.configureAndStartPrometheus()
+
+	return srv
+}
+
+func Test_NewServer(t *testing.T) {
+	tests := []struct {
+		name    string
+		opts    NewServerOpts
+		wantErr error
+	}{
+		{
+			"success",
+			NewServerOpts{
+				Echo:        echo.New(),
+				CorsOrigins: make([]string, 0),
+			},
+			nil,
+		},
+		{
+			"noCorsOrigins",
+			NewServerOpts{
+				Echo: echo.New(),
+			},
+			nil,
+		},
+		{
+			"noHttpFramework",
+			NewServerOpts{
+				CorsOrigins: make([]string, 0),
+			},
+			ErrNoHTTPFramework,
+		},
+	}
+
+	for _, tt := range tests {
+		_, err := NewServer(tt.opts)
+		assert.Equal(t, tt.wantErr, err)
+	}
+}
+
+func Test_Health(t *testing.T) {
+	srv := newTestServer("")
+
+	req, _ := http.NewRequest(echo.GET, "/healthz", nil)
+	rec := httptest.NewRecorder()
+
+	srv.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("Test_Health expected code %v, got %v", http.StatusOK, rec.Code)
+	}
+}
+
+func Test_Metrics(t *testing.T) {
+	srv := newTestServer("")
+
+	req, _ := http.NewRequest(echo.GET, "/metrics", nil)
+	rec := httptest.NewRecorder()
+
+	srv.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("Test_Metrics expected code %v, got %v", http.StatusOK, rec.Code)
+	}
+}
+
+func Test_StartShutdown(t *testing.T) {
+	srv := newTestServer("")
+
+	go func() {
+		_ = srv.Start(":3928")
+	}()
+	assert.Nil(t, srv.Shutdown(context.Background()))
+}