diff --git a/pdns-mysql/docker-entrypoint.sh b/pdns-mysql/docker-entrypoint.sh
index 0865131..41014bb 100755
--- a/pdns-mysql/docker-entrypoint.sh
+++ b/pdns-mysql/docker-entrypoint.sh
@@ -2,65 +2,90 @@
 
 set -eu
 
-# Configure mysql env vars
-: "${PDNS_gmysql_host:=${MYSQL_ENV_MYSQL_HOST:-mysql}}"
-: "${PDNS_gmysql_port:=${MYSQL_ENV_MYSQL_PORT:-3306}}"
-: "${PDNS_gmysql_user:=${MYSQL_ENV_MYSQL_USER:-root}}"
-if [ "${PDNS_gmysql_user}" = 'root' ]; then
-    : "${PDNS_gmysql_password:=${MYSQL_ENV_MYSQL_ROOT_PASSWORD:-}}"
-fi
-: "${PDNS_gmysql_password:=${MYSQL_ENV_MYSQL_PASSWORD:-powerdns}}"
-: "${PDNS_gmysql_dbname:=${MYSQL_ENV_MYSQL_DATABASE:-powerdns}}"
-
-# Use first part of node name as database name suffix
-if [ "${NODE_NAME:-}" ]; then
-    NODE_NAME=$(echo "${NODE_NAME}" | sed -e 's/\..*//' -e 's/-//')
-    PDNS_gmysql_dbname="${PDNS_gmysql_dbname}${NODE_NAME}"
-fi
-
-export PDNS_gmysql_host PDNS_gmysql_port PDNS_gmysql_user PDNS_gmysql_password PDNS_gmysql_dbname
+##### Function definitions ####
 
 
-EXTRA=''
+function deriveMySQLSettingsFromExistingConfigFile {
+  if [ ! -f /etc/pdns/pdns.conf ]; then
+    echo "Use of existing file /etc/pdns/pdns.conf requested but file does not exist!"
+    exit 1
+  fi
+  PDNS_gmysql_host=`sed -n 's/^gmysql-host=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gmysql_port=`sed -n 's/^gmysql-port=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gmysql_user=`sed -n 's/^gmysql-user=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gmysql_password=`sed -n 's/^gmysql-password=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gmysql_dbname=`sed -n 's/^gmysql-dbname=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+}
 
-# Password Auth
-if [ "${PDNS_gmysql_password}" ]; then
-    EXTRA="${EXTRA} -p${PDNS_gmysql_password}"
-fi
+function deriveMySQLSettingsFromEnvironment {
+  # Configure mysql env vars
+  : "${PDNS_gmysql_host:=${MYSQL_ENV_MYSQL_HOST:-mysql}}"
+  : "${PDNS_gmysql_port:=${MYSQL_ENV_MYSQL_PORT:-3306}}"
+  : "${PDNS_gmysql_user:=${MYSQL_ENV_MYSQL_USER:-root}}"
+  if [ "${PDNS_gmysql_user}" = 'root' ]; then
+      : "${PDNS_gmysql_password:=${MYSQL_ENV_MYSQL_ROOT_PASSWORD:-}}"
+  fi
+  : "${PDNS_gmysql_password:=${MYSQL_ENV_MYSQL_PASSWORD:-powerdns}}"
+  : "${PDNS_gmysql_dbname:=${MYSQL_ENV_MYSQL_DATABASE:-powerdns}}"
+  
+  # Use first part of node name as database name suffix
+  if [ "${NODE_NAME:-}" ]; then
+      NODE_NAME=$(echo "${NODE_NAME}" | sed -e 's/\..*//' -e 's/-//')
+      PDNS_gmysql_dbname="${PDNS_gmysql_dbname}${NODE_NAME}"
+  fi
+  
+  export PDNS_gmysql_host PDNS_gmysql_port PDNS_gmysql_user PDNS_gmysql_password PDNS_gmysql_dbname
+}
 
-# Allow socket connections
-if [ "${PDNS_gmysql_socket:-}" ]; then
-    export PDNS_gmysql_host='localhost'
-    EXTRA="${EXTRA} --socket=${PDNS_gmysql_socket}"
-fi
+function generateMySQLCommand {
+  EXTRA=''
+  
+  # Password Auth
+  if [ "${PDNS_gmysql_password}" ]; then
+      EXTRA="${EXTRA} -p${PDNS_gmysql_password}"
+  fi
+  
+  # Allow socket connections
+  if [ "${PDNS_gmysql_socket:-}" ]; then
+      export PDNS_gmysql_host='localhost'
+      EXTRA="${EXTRA} --socket=${PDNS_gmysql_socket}"
+  fi
+  
+  MYSQL_COMMAND="mysql -h ${PDNS_gmysql_host} -P ${PDNS_gmysql_port} -u ${PDNS_gmysql_user}${EXTRA}"
+}
 
-MYSQL_COMMAND="mysql -h ${PDNS_gmysql_host} -P ${PDNS_gmysql_port} -u ${PDNS_gmysql_user}${EXTRA}"
 
-# Wait for MySQL to respond
-until $MYSQL_COMMAND -e ';' ; do
-    >&2 echo 'MySQL is unavailable - sleeping'
-    sleep 3
-done
+function createDatabaseIfRequested {
+  # Initialize DB if needed
+  if [ "${SKIP_DB_CREATE:-false}" != 'true' ]; then
+      $MYSQL_COMMAND -e "CREATE DATABASE IF NOT EXISTS ${PDNS_gmysql_dbname}"
+  fi
+}
 
-# Initialize DB if needed
-if [ "${SKIP_DB_CREATE:-false}" != 'true' ]; then
-    $MYSQL_COMMAND -e "CREATE DATABASE IF NOT EXISTS ${PDNS_gmysql_dbname}"
-fi
+function initDatabase {
+  if [ "${SKIP_DB_INIT:-false}" != 'true'  ]; then
+    MYSQL_CHECK_IF_HAS_TABLE="SELECT COUNT(DISTINCT table_name) FROM information_schema.columns WHERE table_schema = '${PDNS_gmysql_dbname}';"
+    MYSQL_NUM_TABLE=$($MYSQL_COMMAND --batch --skip-column-names -e "$MYSQL_CHECK_IF_HAS_TABLE")
+    if [ "$MYSQL_NUM_TABLE" -eq 0 ]; then
+      echo "Database exists and has no tables yet, doing init";
+      $MYSQL_COMMAND -D "$PDNS_gmysql_dbname" < /usr/share/doc/pdns/schema.mysql.sql
+    else
+      echo "Database exists but already has tables, will not try to init";
+    fi
+  fi
+}
 
-MYSQL_CHECK_IF_HAS_TABLE="SELECT COUNT(DISTINCT table_name) FROM information_schema.columns WHERE table_schema = '${PDNS_gmysql_dbname}';"
-MYSQL_NUM_TABLE=$($MYSQL_COMMAND --batch --skip-column-names -e "$MYSQL_CHECK_IF_HAS_TABLE")
-if [ "$MYSQL_NUM_TABLE" -eq 0 ]; then
-    $MYSQL_COMMAND -D "$PDNS_gmysql_dbname" < /usr/share/doc/pdns/schema.mysql.sql
-fi
-
-# SQL migration to version 4.7
-MYSQL_CHECK_IF_47="SELECT COUNT(*) FROM information_schema.columns WHERE table_schema = '${PDNS_gmysql_dbname}' AND table_name = 'domains' AND column_name = 'options';"
-MYSQL_NUM_TABLE=$($MYSQL_COMMAND --batch --skip-column-names -e "$MYSQL_CHECK_IF_47")
-if [ "$MYSQL_NUM_TABLE" -eq 0 ]; then
+function migrateDatabaseTo47 {
+  # SQL migration to version 4.7
+  MYSQL_CHECK_IF_47="SELECT COUNT(*) FROM information_schema.columns WHERE table_schema = '${PDNS_gmysql_dbname}' AND table_name = 'domains' AND column_name = 'options';"
+  MYSQL_NUM_TABLE=$($MYSQL_COMMAND --batch --skip-column-names -e "$MYSQL_CHECK_IF_47")
+  if [ "$MYSQL_NUM_TABLE" -eq 0 ]; then
     echo 'Migrating MySQL schema to version 4.7...'
     $MYSQL_COMMAND -D "$PDNS_gmysql_dbname" < /usr/share/doc/pdns/4.3.0_to_4.7.0_schema.mysql.sql
-fi
+  fi
+}
 
+function initSuperslave {
 if [ "${PDNS_superslave:-no}" = 'yes' ]; then
     # Configure supermasters if needed
     if [ "${SUPERMASTER_IPS:-}" ]; then
@@ -83,8 +108,41 @@ if [ "${PDNS_superslave:-no}" = 'yes' ]; then
         $MYSQL_COMMAND -D "$PDNS_gmysql_dbname" -e "$MYSQL_INSERT_SUPERMASTERS"
     fi
 fi
+}
 
-# Create config file from template
-subvars --prefix 'PDNS_' < '/pdns.conf.tpl' > '/etc/pdns/pdns.conf'
+function generateAndInstallConfigFileFromEnvironment {
+  # Create config file from template
+  subvars --prefix 'PDNS_' < '/pdns.conf.tpl' > '/etc/pdns/pdns.conf'
+}
+
+
+#### End of function definitions, let's get to work ... 
+
+if [ ${USE_EXISTING_CONFIG_FILE:-false} = 'true' ]; then 
+  deriveMySQLSettingsFromExistingConfigFile
+else
+  deriveMySQLSettingsFromEnvironment
+fi    
+
+generateMySQLCommand
+
+# Wait for MySQL to respond
+until $MYSQL_COMMAND -e ';' ; do
+    >&2 echo 'MySQL is unavailable - sleeping'
+    sleep 3
+done
+
+
+createDatabaseIfRequested
+initDatabase
+migrateDatabaseTo47
+initSuperslave
+
+if [ ${USE_EXISTING_CONFIG_FILE:-false} = 'false' ]; then 
+  echo "(re-)generating config file from environment variables"
+  generateAndInstallConfigFileFromEnvironment
+fi
 
 exec "$@"
+
+
diff --git a/pdns-pgsql/docker-entrypoint.sh b/pdns-pgsql/docker-entrypoint.sh
index 68f7b95..7db548a 100755
--- a/pdns-pgsql/docker-entrypoint.sh
+++ b/pdns-pgsql/docker-entrypoint.sh
@@ -2,25 +2,102 @@
 
 set -eu
 
-# Configure gpgsql env vars
-: "${PDNS_gpgsql_host:=pgsql}"
-: "${PDNS_gpgsql_port:=5432}"
-: "${PDNS_gpgsql_user:=${PGSQL_ENV_POSTGRES_USER:-postgres}}"
-: "${PDNS_gpgsql_password:=${PGSQL_ENV_POSTGRES_PASSWORD:-powerdns}}"
-: "${PDNS_gpgsql_dbname:=${PGSQL_ENV_POSTGRES_DB:-powerdns}}"
+function derivePostgreSQLSettingsFromExistingConfigFile {
+  if [ ! -f /etc/pdns/pdns.conf ]; then
+    echo "Use of existing file /etc/pdns/pdns.conf requested but file does not exist!"
+    exit 1
+  fi
+  PDNS_gpgsql_host=`sed -n 's/^gpgsql-host=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gpgsql_port=`sed -n 's/^gpgsql-port=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gpgsql_user=`sed -n 's/^gpgsql-user=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gpgsql_password=`sed -n 's/^gpgsql-password=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+  PDNS_gpgsql_dbname=`sed -n 's/^gpgsql-dbname=\(.*\)/\1/p' < /etc/pdns/pdns.conf`
+}
 
-# Use first part of node name as database name suffix
-if [ "${NODE_NAME:-}" ]; then
-    NODE_NAME=$(echo "${NODE_NAME}" | sed -e 's/\..*//' -e 's/-//')
-    PDNS_gpgsql_dbname="${PDNS_gpgsql_dbname}${NODE_NAME}"
+function derivePostgreSQLSettingsFromEnvironment {
+  # Configure gpgsql env vars
+  : "${PDNS_gpgsql_host:=pgsql}"
+  : "${PDNS_gpgsql_port:=5432}"
+  : "${PDNS_gpgsql_user:=${PGSQL_ENV_POSTGRES_USER:-postgres}}"
+  : "${PDNS_gpgsql_password:=${PGSQL_ENV_POSTGRES_PASSWORD:-powerdns}}"
+  : "${PDNS_gpgsql_dbname:=${PGSQL_ENV_POSTGRES_DB:-powerdns}}"
+  
+  # Use first part of node name as database name suffix
+  if [ "${NODE_NAME:-}" ]; then
+      NODE_NAME=$(echo "${NODE_NAME}" | sed -e 's/\..*//' -e 's/-//')
+      PDNS_gpgsql_dbname="${PDNS_gpgsql_dbname}${NODE_NAME}"
+  fi
+  
+  export PDNS_gpgsql_host PDNS_gpgsql_port PDNS_gpgsql_user PDNS_gpgsql_password PDNS_gpgsql_dbname
+}
+
+
+
+function generatePostgreSQLCommand {
+  PGSQL_COMMAND="psql -h ${PDNS_gpgsql_host} -p ${PDNS_gpgsql_port} -U ${PDNS_gpgsql_user}"
+}
+
+function createDatabaseIfRequested {
+  # Initialize DB if needed
+  if [ "${SKIP_DB_CREATE:-false}" != 'true' ]; then
+      echo "SELECT 'CREATE DATABASE ${PDNS_gpgsql_dbname}' WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = '${PDNS_gpgsql_dbname}')\gexec" | $PGSQL_COMMAND
+  fi
+}
+
+function initDatabase {
+  if [ "${SKIP_DB_INIT:-false}" != 'true'  ]; then
+    PGSQL_CHECK_IF_HAS_TABLE="SELECT COUNT(DISTINCT table_name) FROM information_schema.columns WHERE table_catalog = '${PDNS_gpgsql_dbname}' AND table_schema = 'public';"
+    PGSQL_NUM_TABLE=$($PGSQL_COMMAND -At -d "$PDNS_gpgsql_dbname" -c "$PGSQL_CHECK_IF_HAS_TABLE")
+    if [ "$PGSQL_NUM_TABLE" -eq 0 ]; then
+      echo "Database exists and has no tables yet, doing init";
+      $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" < /usr/share/doc/pdns/schema.pgsql.sql
+    else
+      echo "Database exists but already has tables, will not try to init";
+    fi
+  fi 
+}
+
+function initSuperslave {
+  if [ "${PDNS_superslave:-no}" = 'yes' ]; then
+      # Configure supermasters if needed
+      if [ "${SUPERMASTER_IPS:-}" ]; then
+          $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" -c 'TRUNCATE supermasters;'
+          PGSQL_INSERT_SUPERMASTERS=''
+          if [ "${SUPERMASTER_COUNT:-0}" -eq 0 ]; then
+              SUPERMASTER_COUNT=10
+          fi
+          i=1; while [ $i -le "${SUPERMASTER_COUNT}" ]; do
+              SUPERMASTER_HOST=$(echo "${SUPERMASTER_HOSTS:-}" | awk -v col="$i" '{ print $col }')
+              SUPERMASTER_IP=$(echo "${SUPERMASTER_IPS}" | awk -v col="$i" '{ print $col }')
+              if [ -z "${SUPERMASTER_HOST:-}" ]; then
+                  SUPERMASTER_HOST=$(hostname -f)
+              fi
+              if [ "${SUPERMASTER_IP:-}" ]; then
+                  PGSQL_INSERT_SUPERMASTERS="${PGSQL_INSERT_SUPERMASTERS} INSERT INTO supermasters VALUES('${SUPERMASTER_IP}', '${SUPERMASTER_HOST}', 'admin');"
+              fi
+              i=$(( i + 1 ))
+          done
+          $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" -c "$PGSQL_INSERT_SUPERMASTERS"
+      fi
+  fi
+}
+
+function generateAndInstallConfigFileFromEnvironment {
+  # Create config file from template
+  subvars --prefix 'PDNS_' < '/pdns.conf.tpl' > '/etc/pdns/pdns.conf'
+}
+###End of function definitions
+
+if [ ${USE_EXISTING_CONFIG_FILE:-false} = 'true' ]; then 
+  derivePostgreSQLSettingsFromExistingConfigFile
+else
+  derivePostgreSQLSettingsFromEnvironment
 fi
 
-export PDNS_gpgsql_host PDNS_gpgsql_port PDNS_gpgsql_user PDNS_gpgsql_password PDNS_gpgsql_dbname
-
+generatePostgreSQLCommand
 
 PGPASSWORD="${PDNS_gpgsql_password}"
 export PGPASSWORD
-PGSQL_COMMAND="psql -h ${PDNS_gpgsql_host} -p ${PDNS_gpgsql_port} -U ${PDNS_gpgsql_user}"
 
 # Wait for pgsql to respond
 until $PGSQL_COMMAND -c ';' ; do
@@ -28,43 +105,16 @@ until $PGSQL_COMMAND -c ';' ; do
     sleep 3
 done
 
-# Initialize DB if needed
-if [ "${SKIP_DB_CREATE:-false}" != 'true' ]; then
-    echo "SELECT 'CREATE DATABASE ${PDNS_gpgsql_dbname}' WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = '${PDNS_gpgsql_dbname}')\gexec" | $PGSQL_COMMAND
+createDatabaseIfRequested
+initDatabase
+initSuperslave
+
+if [ ${USE_EXISTING_CONFIG_FILE:-false} = 'false' ]; then 
+  echo "(re-)generating config file from environment variables"
+  generateAndInstallConfigFileFromEnvironment
 fi
 
-PGSQL_CHECK_IF_HAS_TABLE="SELECT COUNT(DISTINCT table_name) FROM information_schema.columns WHERE table_catalog = '${PDNS_gpgsql_dbname}' AND table_schema = 'public';"
-PGSQL_NUM_TABLE=$($PGSQL_COMMAND -At -d "$PDNS_gpgsql_dbname" -c "$PGSQL_CHECK_IF_HAS_TABLE")
-if [ "$PGSQL_NUM_TABLE" -eq 0 ]; then
-    $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" < /usr/share/doc/pdns/schema.pgsql.sql
-fi
-
-if [ "${PDNS_superslave:-no}" = 'yes' ]; then
-    # Configure supermasters if needed
-    if [ "${SUPERMASTER_IPS:-}" ]; then
-        $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" -c 'TRUNCATE supermasters;'
-        PGSQL_INSERT_SUPERMASTERS=''
-        if [ "${SUPERMASTER_COUNT:-0}" -eq 0 ]; then
-            SUPERMASTER_COUNT=10
-        fi
-        i=1; while [ $i -le "${SUPERMASTER_COUNT}" ]; do
-            SUPERMASTER_HOST=$(echo "${SUPERMASTER_HOSTS:-}" | awk -v col="$i" '{ print $col }')
-            SUPERMASTER_IP=$(echo "${SUPERMASTER_IPS}" | awk -v col="$i" '{ print $col }')
-            if [ -z "${SUPERMASTER_HOST:-}" ]; then
-                SUPERMASTER_HOST=$(hostname -f)
-            fi
-            if [ "${SUPERMASTER_IP:-}" ]; then
-                PGSQL_INSERT_SUPERMASTERS="${PGSQL_INSERT_SUPERMASTERS} INSERT INTO supermasters VALUES('${SUPERMASTER_IP}', '${SUPERMASTER_HOST}', 'admin');"
-            fi
-            i=$(( i + 1 ))
-        done
-        $PGSQL_COMMAND -d "$PDNS_gpgsql_dbname" -c "$PGSQL_INSERT_SUPERMASTERS"
-    fi
-fi
 
 unset PGPASSWORD
 
-# Create config file from template
-subvars --prefix 'PDNS_' < '/pdns.conf.tpl' > '/etc/pdns/pdns.conf'
-
 exec "$@"
diff --git a/pdns-recursor/docker-entrypoint.sh b/pdns-recursor/docker-entrypoint.sh
index a7caca3..7d9f63e 100755
--- a/pdns-recursor/docker-entrypoint.sh
+++ b/pdns-recursor/docker-entrypoint.sh
@@ -2,12 +2,17 @@
 
 set -eu
 
-# Configure base vars
-: "${PDNS_local_port:=53}"
-: "${PDNS_local_address:=0.0.0.0}"
-: "${PDNS_allow_from:=0.0.0.0/0}"
+#### Function definitions
+function deriveConfigValuesFromEnvrionement {
+  # Configure base vars
+  : "${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
+}
 
-export PDNS_local_port PDNS_local_address PDNS_allow_from
+### end of function definitions
 
 if [ -f /etc/fedora-release ]; then
   config_file=/etc/pdns-recursor/recursor.conf
@@ -17,10 +22,18 @@ elif [ -f /etc/alpine-release ]; then
   pdns_user=recursor
 fi
 
+if [ ${USE_EXISTING_CONFIG_FILE:-false} = 'false' ]; then 
+    deriveConfigValuesFromEnvrionement
+    echo "generating config file from environment"
+    subvars --prefix 'PDNS_' < '/recursor.conf.tpl' > "${config_file}"
+    chown "${pdns_user}:" "${config_file}"
+  else
+    echo "using existing config file ${config_file}"
+fi    
+
 # Create config file from template
-subvars --prefix 'PDNS_' < '/recursor.conf.tpl' > "${config_file}"
 
 # Fix config file ownership
-chown "${pdns_user}:" "${config_file}"
+
 
 exec "$@"