Add netns shell script

scripts/dev-netns-shell.sh

@@ -0,0 +1,68 @@
+#!/bin/bash
+
+ns=""
+
+while getopts h-: option; do
+    case "${option}" in
+        -)
+            case "${OPTARG}" in
+                ns)
+                    val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
+                    ns=$val
+                    ;;
+                ns=*)
+                    val=${OPTARG#*=}
+                    ns=$val
+                    ;;
+                *)
+                    if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
+                        echo "Unknown option --${OPTARG}" >&2
+                    fi
+                    ;;
+            esac;;
+        h)
+            echo $(basename $0): usage: $(basename $0) [-h] [--ns=name] [dev] [dev]
+            exit 0
+            ;;
+    esac
+done
+shift $((OPTIND -1))
+
+dev=$1
+
+if [ -z "$ns" ]; then
+    if [ -z "$dev" ]; then
+        echo "Error: must specify either device or network namespace name"
+        exit 1
+    fi
+
+    ns=$dev
+fi
+
+if [ -f "/var/run/netns/$ns" ]; then
+    echo "Network namespace '$ns' already exists"
+else
+    echo "Creating network namespace '$ns'"
+    ip netns add $ns
+    for d in "$@"
+    do
+        echo "Adding interface '$d' to network namespace '$ns'"
+        ip link set dev $d netns $ns
+        ip netns exec $ns ip link set dev $d up
+    done
+fi
+
+if [ -f "/var/run/netns/$ns" ]; then
+    echo "Starting shell in network namespace '$ns'"
+    echo "Note: \$dev='$dev'"
+    export dev
+    ip netns exec $ns bash
+else
+    echo "Error: network namespace not found"
+fi
+
+if [ -f "/var/run/netns/$ns" -a -z "$(ip netns pids $ns)" ]; then
+    echo "Deleting network namespace '$ns'"
+    ip netns del $ns
+fi
+