Client in Go for Tarantool

The package go-tarantool contains everything you need to connect to Tarantool 1.10+.

The advantage of integrating Go with Tarantool, which is an application server plus a DBMS, is that Go programmers can handle databases and perform on-the-fly recompilations of embedded Lua routines, just as in C, with responses that are faster than other packages according to public benchmarks.

Table of contents

• Installation
  • Build tags
• Documentation
  • API reference
  • Walking-through example
  • Example with encrypting traffic
• Migration guide
• Contributing
• Alternative connectors

Installation

We assume that you have Tarantool version 1.10+ and a modern Linux or BSD operating system.

You need a current version of go, version 1.20 or later (use go version to check the version number). Do not use gccgo-go.

Note: If your go version is older than 1.20 or if go is not installed, download and run the latest tarball from golang.org.

The package go-tarantool is located in tarantool/go-tarantool repository. To download and install, say:

$ go get github.com/tarantool/go-tarantool/v2

This should put the source and binary files in subdirectories of /usr/local/go, so that you can access them by adding github.com/tarantool/go-tarantool to the import {...} section at the start of any Go program.

Build tags

We define multiple build tags.

This allows us to introduce new features without losing backward compatibility.

1. To run fuzz tests with decimals, you can use the build tag:

   go_tarantool_decimal_fuzzing
   

   Note: It crashes old Tarantool versions.

Documentation

Read the Tarantool documentation to find descriptions of terms such as "connect", "space", "index", and the requests to create and manipulate database objects or Lua functions.

In general, connector methods can be divided into two main parts:

• Connect() function and functions related to connecting, and
• Data manipulation functions and Lua invocations such as Insert() or Call().

The supported requests have parameters and results equivalent to requests in the Tarantool CRUD operations. There are also Typed and Async versions of each data-manipulation function.

API Reference

Learn API documentation and examples at pkg.go.dev.

Walking-through example

We can now have a closer look at the example and make some observations about what it does.

package tarantool

import (
	"context"
	"fmt"
	"time"

	"github.com/tarantool/go-tarantool/v2"
	_ "github.com/tarantool/go-tarantool/v2/datetime"
	_ "github.com/tarantool/go-tarantool/v2/decimal"
	_ "github.com/tarantool/go-tarantool/v2/uuid"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	dialer := tarantool.NetDialer{
		Address: "127.0.0.1:3301",
		User: 	 "guest",
	}
	opts := tarantool.Opts{
		Timeout: time.Second,
	}

	conn, err := tarantool.Connect(ctx, dialer, opts)
	if err != nil {
		fmt.Println("Connection refused:", err)
		return
	}

	data, err := conn.Do(
		tarantool.NewInsertRequest(999).Tuple([]interface{}{99999, "BB"})).Get()
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Data:", data)
	}
}

Observation 1: The line "github.com/tarantool/go-tarantool/v2" in the import(...) section brings in all Tarantool-related functions and structures.

Observation 2: Unused import lines are required to initialize encoders and decoders for external msgpack types.

Observation 3: The line starting with "ctx, cancel :=" creates a context object for Connect(). The Connect() call will return an error when a timeout expires before the connection is established.

Observation 4: The line starting with "dialer :=" creates dialer for Connect(). This structure contains fields required to establish a connection.

Observation 5: The line starting with "opts :=" sets up the options for Connect(). In this example, the structure contains only a single value, the timeout. The structure may also contain other settings, see more in documentation for the "Opts" structure.

Observation 6: The line containing "tarantool.Connect" is essential for starting a session. There are three parameters:

• a context,
• the dialer that was set up earlier,
• the option structure that was set up earlier.

There will be only one attempt to connect. If multiple attempts needed, "tarantool.Connect" could be placed inside the loop with some timeout between each try. Example could be found in the example_test, name - ExampleConnect_reconnects.

Observation 7: The err structure will be nil if there is no error, otherwise it will have a description which can be retrieved with err.Error().

Observation 8: The Insert request, like almost all requests, is preceded by the method Do of object conn which is the object that was returned by Connect().

Example with encrypting traffic

For SSL-enabled connections, use OpenSSLDialer from the go-tlsdialer package.

Here is small example with importing the go-tlsdialer library and using the OpenSSLDialer:

package tarantool

import (
	"context"
	"fmt"
	"time"

	"github.com/tarantool/go-tarantool/v2"
	_ "github.com/tarantool/go-tarantool/v2/datetime"
	_ "github.com/tarantool/go-tarantool/v2/decimal"
	_ "github.com/tarantool/go-tarantool/v2/uuid"
	"github.com/tarantool/go-tlsdialer"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	dialer := tlsdialer.OpenSSLDialer{
		Address:     "127.0.0.1:3013", 
		User:        "test", 
		Password:    "test", 
		SslKeyFile:  "testdata/localhost.key",
		SslCertFile: "testdata/localhost.crt",
		SslCaFile:   "testdata/ca.crt",
	}
	opts := tarantool.Opts{
		Timeout: time.Second,
	}

	conn, err := tarantool.Connect(ctx, dialer, opts)
	if err != nil {
		fmt.Println("Connection refused:", err)
		return
	}

	data, err := conn.Do(
		tarantool.NewInsertRequest(999).Tuple([]interface{}{99999, "BB"})).Get()
	if err != nil {
		fmt.Println("Error:", err)
	} else {
		fmt.Println("Data:", data)
	}
}

Note that traffic encryption is only available in Tarantool Enterprise Edition 2.10 or newer.

Migration guide

You can review the changes between major versions in the migration guide.

Contributing

See the contributing guide for detailed instructions on how to get started with our project.

Alternative connectors

There are two other connectors available from the open source community:

• viciious/go-tarantool,
• FZambia/tarantool.

See feature comparison in the documentation.