use tini init

Dockerfile

@@ -4,7 +4,8 @@ RUN apk update && apk add \
     autoconf \
     automake \
     make \
-    gcc
+    gcc \
+    tini
 COPY . /build
 WORKDIR /build
 RUN autoreconf -fi && ./configure && make
@@ -12,5 +13,5 @@ RUN make DESTDIR=/opt install
 
 FROM alpine
 COPY --from=build /opt /
-COPY docker-entrypoint.sh /
-ENTRYPOINT ["/docker-entrypoint.sh"]
+COPY --from=build /sbin/tini /sbin/tini
+ENTRYPOINT ["/sbin/tini", "/usr/local/bin/ptunnel-ng"]

docker-entrypoint.sh

@@ -1,4 +0,0 @@
-#!/bin/sh
-set -e
-/usr/local/bin/ptunnel-ng "$@" &
-wait