add tls conn example

Author: haohanyang

mongod.conf

@@ -0,0 +1,6 @@
+# TLS/SSL Configuration
+net:
+   tls:
+      mode: requireTLS
+      certificateKeyFile: /certs/mongodb.pem
+      CAFile: /certs/ca.pem

pkg/tlsconn/main.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+func main() {
+
+	caFile := "certs/ca.pem"
+	certFile := "certs/mongodb.crt" // public client certificate
+	keyFile := "certs/mongodb.pem"  // private client key
+	passPhrase := "123"             // private client key passphrase
+
+	// Loads CA certificate file
+	caCert, err := os.ReadFile(caFile)
+	if err != nil {
+		panic(err)
+	}
+	caCertPool := x509.NewCertPool()
+	if ok := caCertPool.AppendCertsFromPEM(caCert); !ok {
+		panic("Error: CA file must be in PEM format")
+	}
+	// Loads client certificate files
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+
+	if err != nil {
+		panic(err)
+	}
+	// Instantiates a Config instance
+	tlsConfig := &tls.Config{
+		RootCAs:      caCertPool,
+		Certificates: []tls.Certificate{cert},
+	}
+	uri := "mongodb://localhost:27017/?tls=true&tlsAllowInvalidCertificates=true&sslClientCertificateKeyPassword=" + passPhrase
+	// Sets TLS options in options instance
+	opts := options.Client().ApplyURI(uri).SetTLSConfig(tlsConfig)
+
+	ctx := context.TODO()
+	client, err := mongo.Connect(ctx, opts)
+
+	if err != nil {
+		panic(err)
+	}
+	defer client.Disconnect(ctx)
+
+	err = client.Ping(ctx, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("Connected to MongoDB!")
+}