README
¶
NATS
NATS is a lightweight messaging protocol perfect for your IoT/Robotics projects. It operates over TCP, offers a great number of features but an incredibly simple Pub Sub style model of communicating broadcast messages. NATS is blazingly fast as it is written in Go.
This repository contains the Gobot adaptor/drivers to connect to NATS servers. It uses the NATS Go Client available at https://github.com/nats-io/nats. The NATS project is a project part of the CNCF. Find more information on setting up a NATS server and its capability at http://nats.io/.
The NATS messaging protocol (http://www.nats.io/documentation/internals/nats-protocol-demo/) is really easy to work with and can be practiced by setting up a NATS server using Go or Docker. For information on setting up a server using the source code, visit https://github.com/nats-io/gnatsd. For information on the Docker image up on Docker Hub, see https://hub.docker.com/_/nats/. Getting the server set up is very easy. The server itself is Golang, can be built for different architectures and installs in a small footprint. This is an excellent way to get communications going between your IoT and Robotics projects.
How to Install
Please refer to the main README.md
How to Use
Before running the example, make sure you have an NATS server running somewhere you can connect to (for demo purposes
you could also use the public endpoint demo.nats.io:4222).
package main
import (
"fmt"
"time"
"gobot.io/x/gobot/v2"
"gobot.io/x/gobot/v2/platforms/nats"
)
func main() {
natsAdaptor := nats.NewAdaptor("nats://localhost:4222", 1234)
work := func() {
natsAdaptor.On("hello", func(msg nats.Message) {
fmt.Printf("[Received on %q] %s\n", msg.Subject, string(msg.Data))
})
natsAdaptor.On("hola", func(msg nats.Message) {
fmt.Printf("[Received on %q] %s\n", msg.Subject, string(msg.Data))
})
data := []byte("Hello Gobot!")
gobot.Every(1*time.Second, func() {
natsAdaptor.Publish("hello", data)
})
gobot.Every(5*time.Second, func() {
natsAdaptor.Publish("hola", data)
})
}
robot := gobot.NewRobot("natsBot",
[]gobot.Connection{natsAdaptor},
work,
)
robot.Start()
}
To run with TLS enabled, set the URL scheme prefix to tls://. Make sure the NATS server has TLS enabled and use the
NATS option parameters to pass in the TLS settings to the adaptor. Refer to the github.com/nats-io/go-nats
README for more TLS option parameters.
package main
import (
"fmt"
"time"
natsio "github.com/nats-io/go-nats"
"gobot.io/x/gobot/v2"
"gobot.io/x/gobot/v2/platforms/nats"
)
func main() {
natsAdaptor := nats.NewAdaptor("tls://localhost:4222", 1234, natsio.RootCAs("certs/ca.pem"))
work := func() {
natsAdaptor.On("hello", func(msg nats.Message) {
fmt.Printf("[Received on %q] %s\n", msg.Subject, string(msg.Data))
})
natsAdaptor.On("hola", func(msg nats.Message) {
fmt.Printf("[Received on %q] %s\n", msg.Subject, string(msg.Data))
})
data := []byte("Hello Gobot!")
gobot.Every(1*time.Second, func() {
natsAdaptor.Publish("hello", data)
})
gobot.Every(5*time.Second, func() {
natsAdaptor.Publish("hola", data)
})
}
robot := gobot.NewRobot("natsBot",
[]gobot.Connection{natsAdaptor},
work,
)
robot.Start()
}
Supported Features
- Publish messages
- Respond to incoming message events
- Support for Username/password authentication
- Support for NATS adaptor options to support TLS
Upcoming Features
- Encoded messages (JSON)
- Exposing more NATS Features (tls)
- Simplified tests
License
Copyright (c) 2013-2018 The Hybrid Group. Licensed under the Apache 2.0 license.
Documentation
¶
Overview ¶
Package nats provides Gobot adaptor for the nats message service. Installing:
Please refer to the main [README.md](https://github.com/hybridgroup/gobot/blob/release/README.md)
For further information refer to nats README: https://github.com/hybridgroup/gobot/blob/master/platforms/nats/README.md
Index ¶
- Constants
- type Adaptor
- type Driver
- func (m *Driver) Connection() gobot.Connection
- func (m *Driver) Halt() error
- func (m *Driver) Name() string
- func (m *Driver) On(n string, f func(msg Message)) error
- func (m *Driver) Publish(data interface{}) bool
- func (m *Driver) SetName(name string)
- func (m *Driver) SetTopic(topic string)
- func (m *Driver) Start() error
- func (m *Driver) Topic() string
- type Message
Constants ¶
const ( // Data event when data is available for Driver Data = "data" // Error event when error occurs in Driver Error = "error" )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Adaptor ¶
type Adaptor struct {
Host string
// contains filtered or unexported fields
}
Adaptor is a configuration struct for interacting with a NATS server. Name is a logical name for the adaptor/nats server connection. Host is in the form "localhost:4222" which is the hostname/ip and port of the nats server. ClientID is a unique identifier integer that specifies the identity of the client.
func NewAdaptor ¶
NewAdaptor populates a new NATS Adaptor.
func NewAdaptorWithAuth ¶
func NewAdaptorWithAuth(host string, clientID int, username string, password string, options ...nats.Option) *Adaptor
NewAdaptorWithAuth populates a NATS Adaptor including username and password.
func (*Adaptor) On ¶
On is an event-handler style subscriber to a particular topic (named event). Supply a handler function to use the bytes returned by the server.
type Driver ¶
type Driver struct {
gobot.Eventer
gobot.Commander
// contains filtered or unexported fields
}
Driver for NATS
func (*Driver) Connection ¶
func (m *Driver) Connection() gobot.Connection
Connection returns Connections used by the Driver
func (*Driver) On ¶
On subscribes to data updates for the current device topic, and then calls the message handler function when data is received
Source Files