Get multiport-eswitch mode from metalnet rundir

Dockerfile

@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM --platform=$BUILDPLATFORM golang:1.23 as builder
+FROM --platform=$BUILDPLATFORM golang:1.23 AS builder
 
 ARG GOARCH=''
 

docs/README.md

@@ -10,3 +10,25 @@
 
 ## CRD usage
 * [Usage](./usage/crd_usage.md)
+
+## Multiport-eswitch mode
+When running dpservice with Mellanox in multiport-eswitch mode, it is important to tell metalnet about it:
+```
+metalnet --multiport-eswitch
+```
+or
+```
+echo -n "eswitch" > /var/run/metalnet/mode
+```
+This changes the way metalnet generates identifiers for virtual function representors that are sent over to dpservice.
+
+If pf1-proxy is also in use, it is important to mark it as used in the metalnet VF database:
+```
+mkdir -p /var/lib/metalnet/netfns/claims
+echo -n "$pf1_proxy_vf_pci" > /var/lib/metalnet/netfns/claims/00000001-0000-4000-0000-000000000000
+```
+Where the `$pf1_proxy_vf_pci` is the PCI address of the VF representor for pf1-proxy. This should be the only VF using `mlx5_core` driver instead of the `vfio-pci` driver. One of many ways to retrieve such address is as follows:
+```
+pf1_proxy_vf_name=$(/opt/local/bin/dpdk-devbind.py -s | grep "mlx5Gen Virtual Function" | grep "drv=mlx5_core" | awk -F'if=' '{print $2}' | awk '{print $1}')
+pf1_proxy_vf_pci=$(/opt/local/bin/dpdk-devbind.py -s | grep "mlx5Gen Virtual Function" | grep $pf1_proxy_vf_name | awk '{print $1}')
+```

main.go

@@ -104,7 +104,7 @@ func main() {
 	flag.BoolVar(&enableIPv6Support, "enable-ipv6", false, "Enable IPv6 support")
 	flag.IntVar(&publicVNI, "public-vni", 100, "Virtual network identifier used for public routing announcements.")
 	flag.IPVar(&routerAddress, "router-address", net.IP{}, "The address of the next router.")
-	flag.BoolVar(&multiportEswitchMode, "multiport-eswitch", false, "Enable multiport eswitch support")
+	flag.BoolVar(&multiportEswitchMode, "multiport-eswitch", false, "Enable multiport eswitch support (unless specified in metalnet-dir)")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
@@ -125,6 +125,13 @@ func main() {
 		log.SetLevel(log.DebugLevel)
 	}
 
+	// detect multiport-eswitch mode automatically (overrides command-line)
+	// Usage example: 'echo -n "eswitch" > /var/run/metalnet/mode'
+	modeFilePath := filepath.Join(metalnetDir, "mode")
+	content, err := os.ReadFile(modeFilePath)
+	multiportEswitchMode = err == nil && string(content) == "eswitch"
+	setupLog.Info(fmt.Sprintf("Multiport Eswitch mode set to: %v", multiportEswitchMode))
+
 	defaultRouterAddr.PublicVNI = uint32(publicVNI)
 	defaultRouterAddr.SetBySubsciption = false