Go guide
Connect your Go application to a Redis database
Install Redis and the Redis client, then connect your Go application to a Redis database.
go-redis
go-redis provides Go clients for various flavors of Redis and a type-safe API for each Redis command.
Install
go-redis supports last two Go versions and only works with Go modules.
So, first, you need to initialize a Go module:
go mod init github.com/my/repo
To install go-redis/v9:
go get github.com/redis/go-redis/v9
Connect
To connect to a Redis server:
import (
"context"
"fmt"
"github.com/redis/go-redis/v9"
)
func main() {
client := redis.NewClient(&redis.Options{
Addr: "localhost:6379",
Password: "", // no password set
DB: 0, // use default DB
})
}
Another way to connect is using a connection string.
opt, err := redis.ParseURL("redis://<user>:<pass>@localhost:6379/<db>")
if err != nil {
panic(err)
}
client := redis.NewClient(opt)
Store and retrieve a simple string.
ctx := context.Background()
err := client.Set(ctx, "foo", "bar", 0).Err()
if err != nil {
panic(err)
}
val, err := client.Get(ctx, "foo").Result()
if err != nil {
panic(err)
}
fmt.Println("foo", val)
Store and retrieve a map.
session := map[string]string{"name": "John", "surname": "Smith", "company": "Redis", "age": "29"}
for k, v := range session {
err := client.HSet(ctx, "user-session:123", k, v).Err()
if err != nil {
panic(err)
}
}
userSession := client.HGetAll(ctx, "user-session:123").Val()
fmt.Println(userSession)
Connect to a Redis cluster
To connect to a Redis cluster, use NewClusterClient.
client := redis.NewClusterClient(&redis.ClusterOptions{
Addrs: []string{":16379", ":16380", ":16381", ":16382", ":16383", ":16384"},
// To route commands by latency or randomly, enable one of the following.
//RouteByLatency: true,
//RouteRandomly: true,
})
Connect to your production Redis with TLS
When you deploy your application, use TLS and follow the Redis security guidelines.
Establish a secure connection with your Redis database using this snippet.
// Load client cert
cert, err := tls.LoadX509KeyPair("redis_user.crt", "redis_user_private.key")
if err != nil {
log.Fatal(err)
}
// Load CA cert
caCert, err := os.ReadFile("redis_ca.pem")
if err != nil {
log.Fatal(err)
}
caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(caCert)
client := redis.NewClient(&redis.Options{
Addr: "my-redis.cloud.redislabs.com:6379",
Username: "default", // use your Redis user. More info https://redis.io/docs/latest/operate/oss_and_stack/management/security/acl/
Password: "secret", // use your Redis password
TLSConfig: &tls.Config{
MinVersion: tls.VersionTLS12,
Certificates: []tls.Certificate{cert},
RootCAs: caCertPool,
},
})
//send SET command
err = client.Set(ctx, "foo", "bar", 0).Err()
if err != nil {
panic(err)
}
//send GET command and print the value
val, err := client.Get(ctx, "foo").Result()
if err != nil {
panic(err)
}
fmt.Println("foo", val)
dial tcp: i/o timeout
You get a dial tcp: i/o timeout error when go-redis can't connect to the Redis Server, for example, when the server is down or the port is protected by a firewall. To check if Redis Server is listening on the port, run telnet command on the host where the go-redis client is running.
telnet localhost 6379
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
If you use Docker, Istio, or any other service mesh/sidecar, make sure the app starts after the container is fully available, for example, by configuring healthchecks with Docker and holdApplicationUntilProxyStarts with Istio. For more information, see Healthcheck.