docker-pdns/pdns-recursor/docker-entrypoint.sh

#!/bin/sh

set -euo pipefail

# Configure base vars
: "${PDNS_local_port:=53}"
: "${PDNS_local_address:=0.0.0.0}"
: "${PDNS_allow_from:=0.0.0.0/0}"

export PDNS_local_port PDNS_local_address PDNS_allow_from

if [ -f /etc/fedora-release ]; then
  config_file=/etc/pdns-recursor/recursor.conf
  pdns_user=pdns-recursor
elif [ -f /etc/alpine-release ]; then
  config_file=/etc/pdns/recursor.conf
  pdns_user=recursor
fi

# Create config file from template
subvars --prefix 'PDNS_' < /recursor.conf.tpl > $config_file

# Fix config file ownership
chown ${pdns_user}: $config_file

exec "$@"