[gbm-web] Switch to multi-stage image

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit a91da641f621e7ae181c50e00dfc82f8ef8497fc
Author: Bartłomiej Piotrowski <bpiotrowski gnome org>
Date:   Wed Sep 16 12:42:09 2020 +0200

    Switch to multi-stage image

 flat-manager/Dockerfile         | 17 +++++++++++++++--
 flat-manager/Dockerfile.builder | 12 ------------
 2 files changed, 15 insertions(+), 14 deletions(-)
---
diff --git a/flat-manager/Dockerfile b/flat-manager/Dockerfile
index 6348721..05c19e9 100644
--- a/flat-manager/Dockerfile
+++ b/flat-manager/Dockerfile
@@ -1,3 +1,16 @@
+FROM ubuntu:18.04 as builder
+
+RUN apt-get update && apt-get install -y git libpq-dev curl build-essential libgpgme-dev
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs > rustup.sh && \
+    sh rustup.sh -y -q
+
+RUN git clone https://github.com/flatpak/flat-manager.git && cd flat-manager && \
+    git checkout 0.3.7 && /root/.cargo/bin/cargo fetch
+RUN cd flat-manager && /root/.cargo/bin/cargo build --release
+
+ADD gpg-heartbeat.c /gpg-heartbeat.c
+RUN gcc -s /gpg-heartbeat.c $(gpgme-config --libs --cflags) -o /gpg-heartbeat
+
 FROM ubuntu:18.04
 
 RUN apt-get update && apt-get install -y gnupg2
@@ -6,8 +19,8 @@ RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C793BFA2FA577F07 &&
     apt-get update && apt-get install -y flatpak ostree libpq5 ca-certificates && \
     rm -rf /var/lib/apt/lists/*
 
-ADD flat-manager /usr/local/bin/flat-manager
-ADD gpg-heartbeat /usr/local/bin/gpg-heartbeat
+COPY --from=builder /flat-manager/target/release/flat-manager /usr/local/bin/flat-manager
+COPY --from=builder /gpg-heartbeat /usr/local/bin/gpg-heartbeat
 
 ENV HOME /srv/gnome-build-meta
 EXPOSE 8080