Support host UID/GID for Docker runtime

Dockerfile

@@ -12,7 +12,9 @@ ENV DEBIAN_FRONTEND=noninteractive \
     ANI_CLI_DOWNLOAD_DIR=/downloads \
     ANI_CLI_WEB_HOST=0.0.0.0 \
     ANI_CLI_WEB_PORT=8421 \
-    UPDATE_ON_START=false
+    UPDATE_ON_START=false \
+    USER_UID= \
+    USER_GID=
 
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
@@ -27,6 +29,7 @@ RUN apt-get update \
         patch \
         sed \
         sudo \
+        util-linux \
     && rm -rf /var/lib/apt/lists/*
 
 RUN git clone --depth 1 --branch "${ANI_CLI_BRANCH}" "${ANI_CLI}" /tmp/ani-cli-src \