cleaned up image, added support for controller and error managing

operator/src/switch/Dockerfile

-FROM golang:1.20
+FROM golang:1.20 AS build
+
+WORKDIR /usr/src/bin
+
+COPY ./main.go ./go.mod ./
+
+RUN go build -v -o /usr/local/bin/l2sm-br ./... 
+
+FROM ubuntu:latest 
+
+COPY --from=build /usr/src/bin/ /usr/src/bin/
 
 COPY ./vswitch.ovsschema /tmp/
 
@@ -8,17 +18,10 @@ RUN apt-get update && \
 
 COPY ./setup_switch.sh /usr/local/bin/
 
-WORKDIR /usr/src/bin
-
-COPY ./main.go ./go.mod ./
-
-RUN go build -v -o /usr/local/bin/l2sm-br ./... && \
-    chmod +x /usr/local/bin/setup_switch.sh && \
+RUN chmod +x /usr/local/bin/setup_switch.sh && \
     mkdir /etc/l2sm/
 
 WORKDIR /usr/local/bin
 
 
-CMD [ "./setup_switch.sh" ]
-
-  
\ No newline at end of file
+CMD [ "./setup_switch.sh" ]
\ No newline at end of file

operator/src/switch/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
 	"io/ioutil"
@@ -21,23 +22,24 @@ type Node struct {
 // the second one is the path to the configuration file, in reference to the code.
 func main() {
 
-	configDir := os.Args[len(os.Args)-1]
+	configDir, vhostNumber, nodeName, controllerIP, err := takeArguments()
 
-	vhostNumber := flag.Int("n_vpods", 0, "number of pod interfaces that are going to be attached to the switch")
-	nodeName := flag.String("node_name", "", "name of the node the script is executed in. Required.")
-	flag.Parse()
-
-	if *nodeName == "" {
-		fmt.Println("Please provide the node name using the --node_name flag")
+	if err != nil {
+		fmt.Println("Error:", err)
 		return
 	}
 
-	exec.Command("ovs-vsctl", "add-br", "brtun").Run()
+	err = initializeSwitch(controllerIP)
 
-	exec.Command("ip", "link", "set", "brtun", "up").Run()
+	if err != nil {
+		fmt.Println("Error:", err)
+		return
+	}
+
+	fmt.Println("Switch initialized and connected to the controller.")
 
 	// Set all virtual interfaces up, and connect them to the tunnel bridge:
-	for i := 1; i <= *vhostNumber; i++ {
+	for i := 1; i <= vhostNumber; i++ {
 		vhost := fmt.Sprintf("vhost%d", i)
 		cmd := exec.Command("ip", "link", "set", vhost, "up") // i.e: ip link set vhost1 up
 		if err := cmd.Run(); err != nil {
@@ -46,18 +48,80 @@ func main() {
 		exec.Command("ovs-vsctl", "add-port", "brtun", vhost).Run() // i.e: ovs-vsctl add-port brtun vhost1
 	}
 
+	err = createVxlans(configDir, nodeName)
+
+	if err != nil {
+		fmt.Println("Error:", err)
+		return
+	}
+}
+
+func takeArguments() (string, int, string, string, error) {
+	configDir := os.Args[len(os.Args)-1]
+
+	vhostNumber := flag.Int("n_vpods", 0, "number of pod interfaces that are going to be attached to the switch")
+	nodeName := flag.String("node_name", "", "name of the node the script is executed in. Required.")
+	controllerIP := flag.String("controller_ip", "", "ip where the SDN controller is listening using the OpenFlow13 protocol. Required")
+
+	flag.Parse()
+
+	switch {
+	case *nodeName == "":
+		return "", 0, "", "", errors.New("Node name is not defined")
+	case configDir == "":
+		return "", 0, "", "", errors.New("Config directory is not defined")
+	case *controllerIP == "":
+		return "", 0, "", "", errors.New("Controller IP is not defined")
+	}
+
+	return configDir, *vhostNumber, *nodeName, *controllerIP, nil
+}
+
+func initializeSwitch(controllerIP string) error {
+
+	var err error
+
+	err = exec.Command("ovs-vsctl", "add-br", "brtun").Run()
+
+	if err != nil {
+		return err
+	}
+
+	err = exec.Command("ip", "link", "set", "brtun", "up").Run()
+
+	if err != nil {
+		return err
+	}
+
+	err = exec.Command("ovs-vsctl", "set", "bridge", "brtun", "OpenFlow13").Run()
+
+	if err != nil {
+		return err
+	}
+
+	target := fmt.Sprintf("tcp:%s:6633", controllerIP)
+
+	err = exec.Command("ovs-vsctl", "set-controller", "brtun", target).Run()
+
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func createVxlans(configDir, nodeName string) error {
+
 	/// Read file and save in memory the JSON info
 	data, err := ioutil.ReadFile(configDir)
 	if err != nil {
 		fmt.Println("Error reading input file:", err)
-		return
+		return err
 	}
 
 	var nodes []Node
 	err = json.Unmarshal(data, &nodes)
 	if err != nil {
-		fmt.Println("Error unmarshalling JSON:", err)
-		return
+		return err
 	}
 
 	// Search for the corresponding node in the configuration, according to the first passed parameter.
@@ -68,7 +132,7 @@ func main() {
 	// There's up to 2 ^ 24 possible vnis that are reduced to (2 ^24)/100 because of this measure (2 decimal digits are lost). So in total, a number of 167.772 virtual networks can be created.
 	nodeVniRef := 5
 	for _, node := range nodes {
-		if node.Name == *nodeName {
+		if node.Name == nodeName {
 			nodeIP := strings.TrimSpace(node.NodeIP)
 			for _, neighbor := range node.NeighborNodes {
 				neighborVniRef := 5
@@ -97,9 +161,9 @@ func main() {
 						}
 						_, err := exec.Command("ovs-vsctl", commandArgs...).Output()
 						if err != nil {
-							fmt.Print(fmt.Errorf("Could not create vxlan between node %s and node %s.", node.Name, neighbor))
+							return errors.New(fmt.Sprintf("Could not create vxlan between node %s and node %s.", node.Name, neighbor))
 						} else {
-							fmt.Print(fmt.Sprintf("Created vxlan between node %s and node %s.", node.Name, neighbor))
+							fmt.Println(fmt.Sprintf("Created vxlan between node %s and node %s.", node.Name, neighbor))
 						}
 					}
 					neighborVniRef++
@@ -109,4 +173,5 @@ func main() {
 		}
 		nodeVniRef++
 	}
+	return nil
 }

operator/src/switch/setup_switch.sh

@@ -6,4 +6,4 @@ ovs-vsctl --db=unix:/var/run/openvswitch/db.sock --no-wait init
 
 ovs-vswitchd --pidfile=/var/run/openvswitch/ovs-vswitchd.pid --detach 
 
-l2sm-br --n_vpods=$NVPODS --node_name=$NODENAME /etc/l2sm/switchConfig.json
+l2sm-br --n_vpods=$NVPODS --node_name=$NODENAME --controller_ip=$CONTROLLERIP /etc/l2sm/switchConfig.json