128T network plugin scrips for interfacing Docker containers.

init.sh

#!/usr/bin/env bash

###################################################################
#                                                                 #
# This plugin init script is used to network containers built     #
# with Docker.                                                    #
#                                                                 #
# It expects a container to have been created in advance          #
# (e.g. with '--network="none"'). The name of the container       #
# ('--name') is expected to be passed in as the                   #
# "network-namespace" setting of a host KNI.                      #
#                                                                 #
# It also expects the host kni to be configured with a gateway,   #
# which will become the container address.                        #
#                                                                 #
# If the container is found to be stopped, it will start it.      #
#                                                                 #
# Example:                                                        #
#  $ sudo docker run --name my-ctnr --network="none" -d -t alpine #
#                                                                 #
#  device-interface            docker-int                         #
#      name               docker-int                              #
#      type               host                                    #
#      network-namespace  my-ctnr                                 #
#                                                                 #
#      network-interface  container-int                           #
#          name                    container-int                  #
#                                                                 #
#          address                 10.128.128.1                   #
#              ip-address     10.128.128.1                        #
#              prefix-length  29                                  #
#              gateway        10.128.128.2                        #
#          exit                                                   #
#      exit                                                       #
#  exit                                                           #
#                                                                 #
###################################################################

# import common functions related to namespace operations
source /etc/128technology/plugins/network-scripts/common/namespace_helpers

# read arguments provided to script
for i in "$@"
do
case $i in
  --kni-interface=*)
  KNI_NAME="${i#*=}"
  shift
  ;;
  --kni-ip=*)
  IPADDR="${i#*=}"
  shift
  ;;
  --kni-prefix-length=*)
  PREFIX="${i#*=}"
  shift
  ;;
  --kni-gateway=*)
  GATEWAY="${i#*=}"
  shift
  ;;
  --namespace=*)
  NS_PLUS_NSID="${i#*=}"
  shift
  ;;
  *)
  echo "Got unknown arg $i" 
  ;;
esac
done

# use provided namespace:nsid with namespace_helpers to populate NS and NSID vars
echo "namespace arg provided is $NS_PLUS_NSID" | systemd-cat -t kni-attach
NS=$(namespace_get_name $NS_PLUS_NSID)
NSID=$(namespace_get_id $NS_PLUS_NSID)
echo "namespace is $NS, nsid is $NSID" | systemd-cat -t kni-attach

# check to see if docker is already running
systemctl is-active --quiet docker
if [ $? -ne 0 ] ; then
  echo "docker not running, starting docker" | systemd-cat -t kni-attach
  systemd-cat -t kni-attach systemctl start docker
fi

# check to see if docker container exists
docker container inspect $NS &> /dev/null
if [ $? -ne 0 ] ; then
  echo "ERROR: $NS container does not exist in Docker"
  exit 1
fi

# start container
echo "starting $NS docker container"
systemd-cat -t kni-attach docker start $NS

# populate docker container namespace variable
DOCKER_NS="$(docker inspect --format='{{.NetworkSettings.SandboxKey}}' $NS)"

# if the desired namespace isn't found, link it to the Docker namespace
if [ ! -e "/var/run/netns/$NS" ]; then
  echo "Linking $NS to $DOCKER_NS" | systemd-cat -t kni-attach
  systemd-cat -t kni-attach ln -sf $DOCKER_NS /var/run/netns/$NS
  systemd-cat -t kni-attach ip netns set $NS $NSID
fi

# set up KNI if it exists in the default namespace
if [ -d "/sys/devices/virtual/net/$KNI_NAME" ]; then
  echo "$KNI_NAME found in default namespace." | systemd-cat -t kni-attach
  echo "Moving $KNI_NAME to $NS: net=$IPADDR/$PREFIX gw=$GATEWAY." | systemd-cat -t kni-attach
  systemd-cat -t kni-attach ip link set $KNI_NAME netns $NS
  systemd-cat -t kni-attach ip netns exec $NS ip address add $IPADDR/$PREFIX dev $KNI_NAME
  systemd-cat -t kni-attach ip netns exec $NS ip link set $KNI_NAME up
  systemd-cat -t kni-attach ip netns exec $NS ip route add default via $GATEWAY dev $KNI_NAME
fi

shutdown.sh

#!/usr/bin/env bash

# import common functions related to namespace operations
source /etc/128technology/plugins/network-scripts/common/namespace_helpers

# read arguments provided to script
for i in "$@"
do
case $i in
  --kni-interface=*)
  KNI_NAME="${i#*=}"
  shift
  ;;
  --kni-ip=*)
  IPADDR="${i#*=}"
  shift
  ;;
  --kni-prefix-length=*)
  PREFIX="${i#*=}"
  shift
  ;;
  --kni-gateway=*)
  GATEWAY="${i#*=}"
  shift
  ;;
  --namespace=*)
  NS_PLUS_NSID="${i#*=}"
  shift
  ;;
  *)
  echo "Got unknown arg $i"
  ;;
esac
done

# use provided namespace:nsid with namespace_helpers to populate NS and NSID vars
NS=$(namespace_get_name $NS_PLUS_NSID)

# clean up namespace link
echo "unlinking /var/run/netns/$NS" | systemd-cat -t kni-attach
systemd-cat -t kni-attach unlink /var/run/netns/$NS

# stop container
echo "stopping $NS docker container" | systemd-cat -t kni-attach
docker stop $NS