gateway service config file

Author: RoanBrand

README.md

@@ -11,13 +11,15 @@ Included in this repo is an implementation of the Protocol **Gateway** and **Cli
 The following clients are also available:
 
 | Client | Platform | Language |
-| ---------------------------------------------------------------------------------------------- |:--------:| --------:|
+| ---------------------------------------------------------------------------------------------- |:--------:|:--------:|
 | [ArduinoSerialToTCPBridgeClient](https://github.com/RoanBrand/ArduinoSerialToTCPBridgeClient) | Arduino | C++ |
 | [STM32SerialToTCPBridgeClient](https://github.com/RoanBrand/STM32SerialToTCPBridgeClient) | STM32 | C |
 
 #### Use
-- Open a terminal, then run `go get -u github.com/RoanBrand/SerialToTCPBridgeProtocol`.
-- Run the binary in `$GOPATH/bin`.
+- Install [Go](https://golang.org/) and set your `$GOPATH`.
+- Open a terminal, then run `go get -u github.com/RoanBrand/SerialToTCPBridgeProtocol`. This will fetch dependencies and build the gateway service.
+- Copy the *config.json* example to **$GOPATH/bin** next to the binary and set it according to your configuration.
+- Run the binary.
 
 #### Details
 - The protocol provides the app an in order, duplicates free and error checked byte stream by adding a CRC32 and simple retry mechanism. See [this](https://en.wikibooks.org/wiki/Serial_Programming/Error_Correction_Methods) for background.
@@ -32,7 +34,7 @@ The following clients are also available:
  - Run `go test -v` in the terminal.
 
 #### Future plans
-- Add config. Turn into OS service. 
 - Add ping option to periodically test serial line and drop upstream connection if timeout.
 - Multiple connections per client to servers.
 - Capability to scan system and listen on all found COM ports for clients.
+- Turn into OS service.

config.json

@@ -0,0 +1,9 @@
+{
+ "gateways": [
+ {
+ "gateway name": "Gateway for Arduino Uno",
+ "comport name": "COM4",
+ "baud rate": 115200
+ }
+ ]
+}

example.go

@@ -1,23 +1,59 @@
 package main
 
 import (
+"encoding/json"
 "github.com/RoanBrand/SerialToTCPBridgeProtocol/protocol"
 "log"
+"os"
+"sync"
 "time"
 )
 
-const (
-COMPortName = "COM4" // Windows
-//COMPortName = "/dev/serial0" // Linux
-COMBaudRate = 115200
-)
-
 func main() {
-com := protocol.NewComGateway(COMPortName, COMBaudRate)
-for {
-err := com.ServeCOM()
-log.Printf("%v: Error: %v\n", COMPortName, err)
-log.Println("Retrying in 5s...")
-time.Sleep(time.Second * 5)
+c, err := loadConfig()
+if err != nil {
+log.Fatalf(`%v (You must have a valid "config.json" next to the executable)`, err)
+}
+if len(c.Gateways) == 0 {
+log.Fatal("No gateways configured in the config. Exiting.")
+}
+
+w := sync.WaitGroup{}
+for _, v := range c.Gateways {
+w.Add(1)
+go func(v gatewayConfig) {
+com := protocol.NewComGateway(v.COMPortName, v.COMBaudRate)
+for {
+err := com.ServeCOM()
+log.Printf("%v: Error: %v\nRetrying in 5s...\n", v.COMPortName, err)
+time.Sleep(time.Second * 5)
+}
+w.Done()
+}(v)
+}
+w.Wait()
+}
+
+type gatewayConfig struct {
+GatewayName string `json:"gateway name"`
+COMPortName string `json:"comport name"`
+COMBaudRate int `json:"baud rate"`
+}
+
+type config struct {
+Gateways []gatewayConfig `json:"gateways"`
+}
+
+func loadConfig() (*config, error) {
+file, err := os.Open("config.json")
+if err != nil {
+return nil, err
+}
+decoder := json.NewDecoder(file)
+configuration := config{}
+err = decoder.Decode(&configuration)
+if err != nil {
+return nil, err
 }
+return &configuration, nil
 }