templating with bash

nginx.conf

Top of file {
    foo;
    bar;
}

serverlist {
  __SERVERLIST__
}

And more stuff...%     

setup.sh

#!/bin/bash

set -uex

COMPILED_SERVER_LIST=""
NEWLINE=$'\\n'
for var in ${@}
do
    NEXT_LINE="upstream_server ${var};"
    COMPILED_SERVER_LIST="${COMPILED_SERVER_LIST}${NEXT_LINE}${NEWLINE}"
done

cat nginx.conf | sed -e "s/__SERVERLIST__/${COMPILED_SERVER_LIST}/g" > nginx.conf.compiled

What to run

./setup.sh foo 10.0.0.4 10.0.0.5 10.0.0.6