Improve dockerfile

docker/Dockerfile

@@ -3,14 +3,13 @@ FROM golang:1.16 AS build
 # Install dependencies
 RUN apt-get update && apt-get install -y libsecret-1-dev
 
+ARG PROTONMAIL_BRIDGE_VERSION
+
 # Build
 WORKDIR /build/
-COPY VERSION /build/
-
-RUN VERSION=$(cat VERSION) && \
-    curl -L https://github.com/ProtonMail/proton-bridge/archive/refs/tags/${VERSION}.tar.gz \
-        | tar zx --strip-component 1 && \
-    make build-nogui
+RUN curl -L https://github.com/ProtonMail/proton-bridge/archive/refs/tags/${PROTONMAIL_BRIDGE_VERSION}.tar.gz \
+        | tar zx --strip-component 1
+RUN make build-nogui
 
 FROM ubuntu:bionic
 LABEL maintainer="Xiaonan Shen <s@sxn.dev>"
@@ -24,19 +23,20 @@ RUN apt-get update \
         expect socat pass libsecret-1-0 ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
+ENV PATH="/srv/protonmail:$PATH"
+
 # Copy protonmail
-COPY --from=build /build/proton-bridge/proton-bridge /protonmail/
+COPY --from=build /build/proton-bridge /srv/protonmail/
 
 # Copy bash scripts
-COPY gpgparams entrypoint.sh login.exp /protonmail/
+COPY gpgparams entrypoint.sh auto-login.exp login.sh /srv/protonmail/
 
-RUN chmod +x /protonmail/login.exp
-
-# Add a user 'protonmail' with UID 8535
-RUN useradd -u 8535 -d /home/protonmail protonmail \
-    && mkdir -p /home/protonmail \
-    && chown protonmail: /home/protonmail
-# change to non-privileged user for extra security
+# Create use and group for protonmail
+RUN groupadd --gid 8535 protonmail \
+    && useradd --uid 8535 --gid 8535 --home-dir /protonmail protonmail \
+    && mkdir /protonmail \
+    && chown protonmail:protonmail /protonmail
 USER protonmail
+WORKDIR /protonmail
 
-ENTRYPOINT ["bash", "/protonmail/entrypoint.sh"]
+ENTRYPOINT ["bash", "/srv/protonmail/entrypoint.sh"]