Get Ip automatically by network card name

Dockerfile

@@ -14,5 +14,7 @@ RUN \
 FROM alpine:3.7
 RUN apk add --no-cache ca-certificates
 COPY --from=builder /go/src/github.com/gliderlabs/registrator/bin/registrator /bin/registrator
-
-ENTRYPOINT ["/bin/registrator"]
+COPY --from=builder /go/src/github.com/gliderlabs/registrator/docker-entrypoint.sh /usr/local/bin/
+RUN chmod 777 /usr/local/bin/docker-entrypoint.sh
+ENTRYPOINT ["docker-entrypoint.sh"]
+CMD ["/bin/registrator"]

docker-entrypoint.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -e
+
+REGISTRATOR_BIND=
+if [ -n "$REGISTRATOR_BIND_INTERFACE" ]; then
+  REGISTRATOR_BIND_ADDRESS=$(ip -o -4 addr list $REGISTRATOR_BIND_INTERFACE | head -n1 | awk '{print $4}' | cut -d/ -f1)
+  if [ -z "$REGISTRATOR_BIND_ADDRESS" ]; then
+    echo "Could not find IP for interface '$REGISTRATOR_BIND_INTERFACE', exiting"
+    exit 1
+  fi
+
+  REGISTRATOR_BIND="-ip $REGISTRATOR_BIND_ADDRESS"
+  echo "==> Found address '$REGISTRATOR_BIND_ADDRESS' for interface '$REGISTRATOR_BIND_INTERFACE', setting bind option..."
+fi
+
+set -- registrator \
+    $REGISTRATOR_BIND \
+    "$@"
+
+exec "$@"