add binary

Dockerfile

@@ -1,7 +1,24 @@
-FROM alpine
+# build stage
+FROM ubuntu:18.04 AS build
+ENV DEBIAN_FRONTEND=noninteractive TZ=Europe/Berlin
 
-RUN apk update && apk add bash
+RUN apt-get update && \
+    apt-get -y install --no-install-recommends g++ && \
+    rm -rf /var/lib/apt/lists/*
+
+COPY main.cpp /app/main.cpp
+WORKDIR /app
+RUN g++ -o main main.cpp
+
+# run stage
+FROM ubuntu:18.04 AS run
+ENV DEBIAN_FRONTEND=noninteractive TZ=Europe/Berlin
+
+RUN apt-get update && \
+    apt-get -y install --no-install-recommends file && \
+    rm -rf /var/lib/apt/lists/*
+
+COPY --from=build /app/main /app/main
 COPY run.sh /app/run.sh
 RUN chmod +x /app/run.sh
-
 CMD ["/app/run.sh"]