feat: init

mysql/.env.example

@@ -0,0 +1,2 @@
+DRIVER_NAME=mysql
+DATA_SOURCE_NAME=keepalive:keepalive@tcp(localhost:3306)/keepalive?tls=custom

mysql/.gitignore

@@ -1,3 +1,8 @@
+.idea
+ca.pem
+
+
+
 # If you prefer the allow list template instead of the deny list, see community template:
 # https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
 #

mysql/Dockerfile

@@ -0,0 +1,40 @@
+ARG GO_VERSION=1.24.10
+FROM --platform=$BUILDPLATFORM golang:${GO_VERSION} AS build
+WORKDIR /src
+
+RUN --mount=type=cache,target=/go/pkg/mod/ \
+    --mount=type=bind,source=go.sum,target=go.sum \
+    --mount=type=bind,source=go.mod,target=go.mod \
+    go mod download -x
+
+ARG TARGETARCH
+
+RUN --mount=type=cache,target=/go/pkg/mod/ \
+    --mount=type=bind,target=. \
+    CGO_ENABLED=0 GOARCH=$TARGETARCH go build -o /bin/server .
+
+FROM alpine:latest AS final
+
+RUN --mount=type=cache,target=/var/cache/apk \
+    apk --update add \
+        ca-certificates \
+        tzdata \
+        && \
+        update-ca-certificates
+
+ARG UID=10001
+RUN adduser \
+    --disabled-password \
+    --gecos "" \
+    --home "/nonexistent" \
+    --shell "/sbin/nologin" \
+    --no-create-home \
+    --uid "${UID}" \
+    appuser
+USER appuser
+
+COPY --from=build /bin/server /bin/
+
+EXPOSE 1999
+
+ENTRYPOINT [ "/bin/server" ]

mysql/go.mod

@@ -0,0 +1,12 @@
+module github.com/tiennm99/mysql-keepalive
+
+go 1.23.12
+
+toolchain go1.24.10
+
+require (
+	github.com/go-sql-driver/mysql v1.9.3
+	github.com/joho/godotenv v1.5.1
+)
+
+require filippo.io/edwards25519 v1.1.0 // indirect

mysql/go.sum

@@ -0,0 +1,6 @@
+filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
+filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
+github.com/go-sql-driver/mysql v1.9.3 h1:U/N249h2WzJ3Ukj8SowVFjdtZKfu9vlLZxjPXV1aweo=
+github.com/go-sql-driver/mysql v1.9.3/go.mod h1:qn46aNg1333BRMNU69Lq93t8du/dwxI64Gl8i5p1WMU=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

mysql/init.sql

@@ -0,0 +1,35 @@
+-- Drop and recreate the database
+DROP
+DATABASE IF EXISTS keepalive;
+CREATE
+DATABASE keepalive;
+
+-- Create user if not exists
+CREATE
+USER IF NOT EXISTS 'keepalive'@'%' IDENTIFIED BY 'keepalive';
+
+-- Grant full permissions on this database
+GRANT ALL PRIVILEGES ON keepalive.* TO
+'keepalive'@'%';
+
+FLUSH
+PRIVILEGES;
+
+-- Create the table for key/value counters
+USE
+keepalive;
+
+CREATE TABLE IF NOT EXISTS keepalive
+(
+    `key`
+    VARCHAR
+(
+    255
+) PRIMARY KEY,
+    `value` BIGINT NOT NULL
+    );
+
+-- Initialize key/value
+INSERT INTO keepalive (`key`, `value`)
+VALUES ('counter', 0) ON DUPLICATE KEY
+UPDATE `value` = 0;

mysql/main.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"database/sql"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/go-sql-driver/mysql"
+	"github.com/joho/godotenv"
+)
+
+func main() {
+	if err := godotenv.Load(); err != nil {
+		log.Println("Warning: .env file not found")
+	}
+
+	driverName, isExist := os.LookupEnv("DRIVER_NAME")
+	if !isExist {
+		log.Fatal("Warning: DRIVER_NAME not set!")
+		return
+	}
+
+	dataSourceName, isExist := os.LookupEnv("DATA_SOURCE_NAME")
+	if !isExist {
+		log.Fatal("Warning: DATA_SOURCE_NAME not set!")
+		return
+	}
+
+	rootCertPool := x509.NewCertPool()
+	pem, err := os.ReadFile("ca.pem")
+	if err != nil {
+		log.Fatal(err)
+	}
+	rootCertPool.AppendCertsFromPEM(pem)
+
+	err = mysql.RegisterTLSConfig("custom", &tls.Config{
+		RootCAs: rootCertPool,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	db, err := sql.Open(driverName, dataSourceName)
+	if err != nil {
+		panic(err)
+	}
+	db.SetConnMaxLifetime(time.Minute * 3)
+	db.SetMaxOpenConns(10)
+	db.SetMaxIdleConns(10)
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		ticker := time.NewTicker(time.Minute)
+		defer ticker.Stop()
+
+		for {
+			select {
+			case <-ticker.C:
+				if err := incrementCounter(ctx, db); err != nil {
+					log.Printf("Keepalive increment error: %v", err)
+				}
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+
+	defer func() {
+		cancel()
+		if err := db.Close(); err != nil {
+			log.Printf("Close error: %v", err)
+			return
+		}
+	}()
+
+	sigCh := make(chan os.Signal, 1)
+	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
+	<-sigCh
+}
+
+func incrementCounter(ctx context.Context, db *sql.DB) error {
+	ctx, cancel := context.WithTimeout(ctx, 3*time.Second)
+	defer cancel()
+
+	tx, err := db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadCommitted})
+	if err != nil {
+		return err
+	}
+
+	_, err = tx.ExecContext(ctx,
+		"UPDATE `keepalive` SET `value` = `value` + 1 WHERE `key` = 'counter'",
+	)
+	if err != nil {
+		tx.Rollback()
+		return err
+	}
+
+	var value int64
+	err = tx.QueryRowContext(ctx,
+		"SELECT `value` FROM `keepalive` WHERE `key` = 'counter'",
+	).Scan(&value)
+	if err != nil {
+		tx.Rollback()
+		return err
+	}
+
+	if err := tx.Commit(); err != nil {
+		return err
+	}
+
+	log.Printf("Counter: %d\n", value)
+	return nil
+}