Add entrypoint shell script

Listen port and database URL can be configured by using
environment variables: IPTOASN_PORT AND IPTOASN_DBURL

Docker container for the iptoasn_webservice may be used as a
binary - arbitrary args will be passed to the service if supplied

docker/Dockerfile

@@ -12,8 +12,13 @@ RUN apk update \
     rust \
     cargo \
     libressl-dev \
+  \
   && cargo build --release \
+  && strip target/release/iptoasn-webservice \
   && mv target/release/iptoasn-webservice /usr/bin/iptoasn-webservice \
+  && mv docker/iptoasn-entrypoint.sh /iptoasn-entrypoint.sh \
+  && chmod +x /iptoasn-entrypoint.sh \
+  \
   && rm -rf  ~/.cargo \
             /var/cache/apk/* \
             /tmp/* \
@@ -22,4 +27,4 @@ RUN apk update \
 RUN adduser -D app
 USER app
 
-ENTRYPOINT /usr/bin/iptoasn-webservice --listen 0.0.0.0:10000
+ENTRYPOINT ["/iptoasn-entrypoint.sh"]

docker/iptoasn-entrypoint.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+DEFAULT_PORT='53661'
+DEFAULT_DBURL='https://iptoasn.com/data/ip2asn-combined.tsv.gz'
+
+if [ $IPTOASN_PORT ] || [ $IPTOASN_DBURL]; then
+  if ! [ $IPTOASN_PORT ]; then
+    IPTOASN_PORT=$DEFAULT_PORT
+  fi
+
+  if ! [ $IPTOASN_DBURL ]; then
+    IPTOASN_DBURL=$DEFAULT_DBURL
+  fi
+
+  exec /usr/bin/iptoasn-webservice --listen 0.0.0.0:"$IPTOASN_PORT" --dburl "$IPTOASN_DBURL"
+else
+  exec /usr/bin/iptoasn-webservice $@
+fi