feat: add health port (#24)

Author: mpetrun5

config/config.go

@@ -14,8 +14,9 @@ type Config struct {
 }
 
 type Observability struct {
-	LogLevel string `default:"debug" split_words:"true"`
-	LogFile  string `default:"out.log" split_words:"true"`
+	LogLevel   string `default:"debug" split_words:"true"`
+	LogFile    string `default:"out.log" split_words:"true"`
+	HealthPort uint16 `default:"9001" split_words:"true"`
 }
 
 type Prover struct {

config/config_test.go

@@ -41,8 +41,9 @@ func (s *ConfigTestSuite) Test_LoadConfig_DefaultValues() {
 	s.Nil(err)
 	s.Equal(c, &config.Config{
 		Observability: &config.Observability{
-			LogLevel: "debug",
-			LogFile:  "out.log",
+			LogLevel:   "debug",
+			LogFile:    "out.log",
+			HealthPort: 9001,
 		},
 		Prover: &config.Prover{
 			URL: "http://prover.com",
@@ -54,6 +55,7 @@ func (s *ConfigTestSuite) Test_LoadConfig_DefaultValues() {
 func (s *ConfigTestSuite) Test_LoadEVMConfig_SuccessfulLoad() {
 	os.Setenv("SPECTRE_OBSERVABILITY_LOG_LEVEL", "info")
 	os.Setenv("SPECTRE_OBSERVABILITY_LOG_FILE", "out2.log")
+	os.Setenv("SPECTRE_OBSERVABILITY_HEALTH_PORT", "9003")
 	os.Setenv("SPECTRE_PROVER_URL", "http://prover.com")
 	os.Setenv("SPECTRE_DOMAINS", "1:evm,2:evm")
 
@@ -65,8 +67,9 @@ func (s *ConfigTestSuite) Test_LoadEVMConfig_SuccessfulLoad() {
 	s.Nil(err)
 	s.Equal(c, &config.Config{
 		Observability: &config.Observability{
-			LogLevel: "info",
-			LogFile:  "out2.log",
+			LogLevel:   "info",
+			LogFile:    "out2.log",
+			HealthPort: 9003,
 		},
 		Prover: &config.Prover{
 			URL: "http://prover.com",

health/health.go

@@ -0,0 +1,21 @@
+// The Licensed Work is (c) 2023 Sygma
+// SPDX-License-Identifier: LGPL-3.0-only
+
+package health
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/rs/zerolog/log"
+)
+
+// StartHealthEndpoint starts /health endpoint on provided port that returns ok on invocation
+func StartHealthEndpoint(port uint16) {
+	http.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte("ok"))
+	})
+
+	_ = http.ListenAndServe(fmt.Sprintf(":%d", port), nil)
+	log.Info().Msgf("started /health endpoint on port %d", port)
+}

main.go

@@ -25,6 +25,7 @@ import (
 	evmMessage "github.com/sygmaprotocol/spectre-node/chains/evm/message"
 	"github.com/sygmaprotocol/spectre-node/chains/evm/prover"
 	"github.com/sygmaprotocol/spectre-node/config"
+	"github.com/sygmaprotocol/spectre-node/health"
 	"github.com/sygmaprotocol/sygma-core/chains/evm"
 	"github.com/sygmaprotocol/sygma-core/chains/evm/client"
 	"github.com/sygmaprotocol/sygma-core/chains/evm/transactor/gas"
@@ -51,6 +52,8 @@ func main() {
 
 	log.Info().Msg("Loaded configuration")
 
+	go health.StartHealthEndpoint(cfg.Observability.HealthPort)
+
 	domains := make([]uint8, 0)
 	for domain := range cfg.Domains {
 		domains = append(domains, domain)