apt-get update
apt-get install gcc g++ make flex bison openssl libssl-dev perl perl-base perl-modules libperl-dev libperl4-corelibs-perl libaio1 libaio-dev \
zlib1g zlib1g-dev libcap-dev cron bzip2 automake autoconf libtool cmake pkg-config python libdb-dev libsasl2-dev \
libncurses5-dev libsystemd-dev bind9 dnsutils quota patch libjemalloc-dev logrotate rsyslog libc6-dev libexpat1-dev \
libcrypt-openssl-rsa-perl libnuma-dev libnuma1 bsd-mailx
Note:
You might need to remove libsystemd-dev from the list, if apt-get cannot find it.
wget http://www.directadmin.com/setup.sh
chmod 755 setup.sh
./setup.sh