build: switch to Go-based multi-stage build and improve

- Use golang:1.26-trixie builder instead of debian:sid
- Build proton-bridge from source via version argument/envelopment
- Add support for PTY tools (dtach, abduco, reptyr) for interactive sessions
- Introduce manage and attach commands for bridge CLI sessions
- Improve daemon startup with port readiness checks
- Add HEALTHCHECK and configurable CMD/ENTRYPOINT
- Harden entrypoint with strict bash flags and better error handling
- Install additional runtime deps (libfido2, procps) and optional PTY tools

build/Dockerfile

@@ -1,33 +1,52 @@
-# The build image could be golang, but it currently does not support riscv64. Only debian:sid does, at the time of writing.
-FROM debian:sid-slim AS build
+### The Deb install is just a repack of the official ProtonMail Bridge deb package with less dependencies.
+### I recommend you don't use this. It's here for legacy reasons.
+
+FROM golang:1.26-trixie AS build
 
 ARG version
+ENV version=${version}
 
-# Install dependencies
-RUN apt-get update && apt-get install -y golang build-essential libsecret-1-dev
+
+RUN apt-get update && apt-get install -y build-essential libsecret-1-dev libfido2-dev libcbor-dev
 
 # Build
 ADD https://github.com/ProtonMail/proton-bridge.git#${version} /build/
 WORKDIR /build/
 RUN make build-nogui vault-editor
 
-FROM debian:sid-slim
+# -----------------------------------------------------------------------------
+
+FROM debian:trixie-slim
 LABEL maintainer="Simon Felding <sife@adm.ku.dk>"
 
+# Select PTY tool for manage/attach commands: dtach (default), abduco, reptyr
+ARG PTY_TOOL=dtach
+ENV PTY_TOOL=${PTY_TOOL}
+
 EXPOSE 25/tcp
 EXPOSE 143/tcp
 
-# Install dependencies and protonmail bridge
-RUN apt-get update \
-    && apt-get install -y --no-install-recommends socat pass libsecret-1-0 ca-certificates \
-    && rm -rf /var/lib/apt/lists/*
+WORKDIR /protonmail
 
-# Copy bash scripts
 COPY gpgparams entrypoint.sh /protonmail/
-
 # Copy protonmail
 COPY --from=build /build/bridge /protonmail/
 COPY --from=build /build/proton-bridge /protonmail/
 COPY --from=build /build/vault-editor /protonmail/
 
-ENTRYPOINT ["bash", "/protonmail/entrypoint.sh"]
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+         socat pass libsecret-1-0 libfido2-1 ca-certificates procps \
+    && case "${PTY_TOOL}" in \
+         dtach)  apt-get install -y --no-install-recommends dtach  ;; \
+         abduco) apt-get install -y --no-install-recommends abduco ;; \
+         reptyr) apt-get install -y --no-install-recommends reptyr ;; \
+       esac \
+    && chmod +x /protonmail/entrypoint.sh \
+    && rm -rf /var/lib/apt/lists/*
+
+HEALTHCHECK --interval=30s --timeout=5s --retries=3 --start-period=120s \
+  CMD /bin/bash -c "true < /dev/tcp/localhost/25"
+
+ENTRYPOINT ["/protonmail/entrypoint.sh"]
+CMD ["run"]