Add DNS Search domains to the Docker For Mac VM

add-dns-search-domains.sh

#!/usr/bin/env bash

# add-dns-search-domain.sh - Tell the Docker for Mac VM to add any search domains
#                            from the host machine's resolv.conf to its own
#                            resolv.conf. Must be run every time networking is
#                            restarted on the Docker VM, or the docker VM
#                            is rebooted


# Find the search domains from the host's resolv.conf
resolvfile=/etc/resolv.conf
tempfile=$(mktemp)
grep search $resolvfile > $tempfile

# Docker HyperKit VM TTY socker
tty_socket=${DOCKER_TTY_SOCKET:-~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty}

# XXX any commands sent to the tty socket are followed by a timeout to give
# the tty time to respond
timeout='sleep 0.5'

echo -e '\04' > $tty_socket && $timeout
# XXX Must be logged out to work!

# Log In as Root
echo 'root' > $tty_socket && $timeout

# Can't copy files directly, so have to cat them through stdout
echo 'export VM_TEMPFILE=$(mktemp)' > $tty_socket && $timeout
echo 'cat <<EOF > $VM_TEMPFILE' > $tty_socket && $timeout
cat $tempfile > $tty_socket && $timeout
echo 'EOF' > $tty_socket && $timeout

# Append the tempfile to the resolver file
echo "cat \$VM_TEMPFILE >> $resolvfile" > $tty_socket && $timeout

# Cleanup
echo 'rm -f $VM_TEMPFILE' > $tty_socket && $timeout
echo -e '\04' > $tty_socket

rm -f $tempfile