graceful shutdown

go.mod

@@ -9,12 +9,15 @@ require (
 
 require (
 	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
+	github.com/jackc/pgx/v5 v5.5.5 // indirect
 	github.com/labstack/gommon v0.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fasttemplate v1.2.2 // indirect
-	golang.org/x/crypto v0.16.0 // indirect
+	golang.org/x/crypto v0.17.0 // indirect
 	golang.org/x/net v0.19.0 // indirect
 	golang.org/x/sys v0.15.0 // indirect
 	golang.org/x/text v0.14.0 // indirect

go.sum

@@ -3,6 +3,12 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
 github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a h1:bbPeKD0xmW/Y25WS6cokEszi5g+S0QxI/d45PkRi7Nk=
+github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.5.5 h1:amBjrZVmksIdNjxGW/IiIMzxMKZFelXbUoPNb+8sjQw=
+github.com/jackc/pgx/v5 v5.5.5/go.mod h1:ez9gk+OAat140fv9ErkZDYFWmXLfV+++K0uAOiwgm1A=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
 github.com/labstack/echo/v4 v4.11.2 h1:T+cTLQxWCDfqDEoydYm5kCobjmHwOwcv4OJAPHilmdE=
@@ -19,6 +25,7 @@ github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
@@ -29,6 +36,8 @@ github.com/valyala/fasttemplate v1.2.2 h1:lxLXG0uE3Qnshl9QyaK6XJxMXlQZELvChBOCmQ
 github.com/valyala/fasttemplate v1.2.2/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
 golang.org/x/crypto v0.16.0 h1:mMMrFzRSCF0GvB7Ne27XVtVAaXLrPmgPC7/v0tkwHaY=
 golang.org/x/crypto v0.16.0/go.mod h1:gCAAfMLgwOJRpTjQ2zCCt2OcSfYMTeZVSRtQlPC7Nq4=
+golang.org/x/crypto v0.17.0 h1:r8bRNjWL3GshPW3gkd+RpvzWrZAwPS49OmTGZ/uhM4k=
+golang.org/x/crypto v0.17.0/go.mod h1:gCAAfMLgwOJRpTjQ2zCCt2OcSfYMTeZVSRtQlPC7Nq4=
 golang.org/x/net v0.19.0 h1:zTwKpTd2XuCqf8huc7Fo2iSy+4RHPd10s4KzeTnVr1c=
 golang.org/x/net v0.19.0/go.mod h1:CfAk/cbD4CthTvqiEl8NpboMuiuOYsAr/7NOjZJtv1U=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

main.go

@@ -1,13 +1,18 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"html/template"
 	"io"
 	"log"
 	"net/http"
 	"os"
+	"os/signal"
+	"syscall"
+	"time"
 
+	"github.com/jackc/pgx/v5"
 	"github.com/joho/godotenv"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
@@ -18,6 +23,12 @@ type TemplateRenderer struct {
 }
 
 func main() {
+	// create a channel to listen for signals
+	sigChan := make(chan os.Signal, 1)
+
+	// listen to SIGTERM and SIGINT (ctrl-c)
+	signal.Notify(sigChan, syscall.SIGTERM, syscall.SIGINT, os.Interrupt)
+
 	// Load connection string from .env file
 	if os.Getenv("GO_ENV") != "production" {
 		fmt.Println("Loading env...")
@@ -33,28 +44,59 @@ func main() {
 		os.Exit(1)
 	}
 
+	conn, err := pgx.Connect(context.Background(), os.Getenv("DB_URL"))
+	if err != nil {
+		log.Fatalf("Error connecting to database: %v\n", err)
+	}
+	defer func() {
+		// shutdown database connection
+		if err := conn.Close(context.Background()); err != nil {
+			log.Printf("Error closing database connection: %v\n", err)
+		} else {
+			log.Println("Database connection closed gracefully.")
+		}
+	}()
+
 	e := echo.New()
 	e.Renderer = &TemplateRenderer{
 		templates: templates,
 	}
 
-	e.Use(middleware.Logger())
+	// serve server in a goroutine, allow the code to listen to ctrl-c
-	e.Static("/static", "static")
+	go func() {
+		e.Use(middleware.Logger())
+		e.Static("/static", "static")
 
-	e.GET("/", renderPage)
+		e.GET("/", renderPage)
 
-	e.GET("/service/health-check", func(c echo.Context) error {
+		e.GET("/service/health-check", func(c echo.Context) error {
-		c.Response().Writer.WriteHeader(http.StatusOK)
+			c.Response().Writer.WriteHeader(http.StatusOK)
-		c.Response().Write([]byte("APP VERSION: 1.0.0"))
+			c.Response().Write([]byte("APP VERSION: 1.0.0"))
-		return nil
+			return nil
-	})
+		})
 
-	port := os.Getenv("PORT")
+		port := os.Getenv("PORT")
-	if port == "" {
+		if port == "" {
-		port = "5173"
+			port = "5173"
+		}
+
+		e.Start(fmt.Sprintf(":%s", port))
+	}()
+
+	// block until a signal is received
+	sig := <-sigChan
+	log.Printf("Caught signal: %s\n", sig)
+
+	// start graceful shutdown with a timeout
+	// should stop everything and clean up within 10 seconds
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	if err := e.Shutdown(ctx); err != nil {
+		log.Printf("Error during server shutdown: %v\n", err)
+	} else {
+		log.Println("Server shut down gracefully.")
 	}
-
-	e.Logger.Fatal(e.Start(fmt.Sprintf(":%s", port)))
 }
 
 func (t *TemplateRenderer) Render(w io.Writer, name string, data interface{}, c echo.Context) error {