use gosu to step down in entrypoint

src/Api/Dockerfile

@@ -3,6 +3,7 @@ FROM microsoft/aspnetcore:2.0.5
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
         cron \
+        gosu \
     && rm -rf /var/lib/apt/lists/*
 
 ENV ASPNETCORE_URLS http://+:5000
@@ -25,5 +26,4 @@ RUN groupadd -g 999 bitwarden \
     && chmod +x /entrypoint.sh \
     && chown bitwarden:bitwarden /entrypoint.sh
 
-USER bitwarden
 ENTRYPOINT ["/entrypoint.sh"]

src/Api/entrypoint.sh

@@ -2,4 +2,5 @@
 
 env >> /etc/environment
 cron
-dotnet /app/Api.dll
+
+gosu bitwarden:bitwarden dotnet /app/Api.dll