Do not use netns as ID or for entropy

ContainerID is now required so use that
or generate random bytes.

Fixes #5

scripts/docker-run.sh

@@ -9,10 +9,10 @@ contid=$(docker run -d --net=none busybox:latest /bin/sleep 10000000)
 pid=$(docker inspect -f '{{ .State.Pid }}' $contid)
 netnspath=/proc/$pid/ns/net
 
-./exec-plugins.sh add $netnspath
+./exec-plugins.sh add $contid $netnspath
 
 function cleanup() {
-	./exec-plugins.sh del $netnspath
+	./exec-plugins.sh del $contid $netnspath
 	docker kill $contid >/dev/null
 }
 trap cleanup EXIT

scripts/exec-plugins.sh

@@ -1,29 +1,36 @@
-#!/bin/bash -e
+#!/bin/bash
 
 NETCONFPATH=${NETCONFPATH-/etc/cni/net.d}
 
 function exec_plugins() {
 	i=0
-	netns=$2
+	contid=$2
+	netns=$3
 	export CNI_COMMAND=$(echo $1 | tr '[:lower:]' '[:upper:]')
 	export PATH=$CNI_PATH:$PATH
+	export CNI_CONTAINERID=$contid
 	export CNI_NETNS=$netns
 
 	for netconf in $(echo $NETCONFPATH/*.conf | sort); do
+		name=$(jq -r '.name' <$netconf)
 		plugin=$(jq -r '.type' <$netconf)
 		export CNI_IFNAME=$(printf eth%d $i)
 
 		$plugin <$netconf >/dev/null
+		if [ $? -ne 0 ]; then
+			echo "${name} : error executing $CNI_COMMAND"
+			exit 1
+		fi
 
 		let "i=i+1"
 	done
 }
 
-if [ $# -ne 2 ]; then
-	echo "Usage: $0 add|del NETNS-PATH"
+if [ $# -ne 3 ]; then
+	echo "Usage: $0 add|del CONTAINER-ID NETNS-PATH"
 	echo "  Adds or deletes the container specified by NETNS-PATH to the networks"
 	echo "  specified in \$NETCONFPATH directory"
 	exit 1
 fi
 
-exec_plugins $1 $2
+exec_plugins $1 $2 $3

scripts/priv-net-run.sh

@@ -3,18 +3,18 @@
 # Run a command in a private network namespace
 # set up by CNI plugins
 
-netnsname=$(printf '%x%x' $RANDOM $RANDOM)
-netnspath=/var/run/netns/$netnsname
+contid=$(printf '%x%x%x%x' $RANDOM $RANDOM $RANDOM $RANDOM)
+netnspath=/var/run/netns/$contid
 
-ip netns add $netnsname
-ip netns exec $netnsname ip link set lo up
-./exec-plugins.sh add $netnspath
+ip netns add $contid
+ip netns exec $contid ip link set lo up
+./exec-plugins.sh add $contid $netnspath
 
 
 function cleanup() {
-	./exec-plugins.sh del $netnspath
-	ip netns delete $netnsname
+	./exec-plugins.sh del $contid $netnspath
+	ip netns delete $contid
 }
 trap cleanup EXIT
 
-ip netns exec $netnsname $@
+ip netns exec $contid $@