openSUSE: speed up package building and testing

builder/dockerfile.opensuse_15.barebones.rpm.test

@@ -8,23 +8,8 @@ RUN zypper -n install -y \
   vim \
   xterm
 
-# deps and rpm install
-RUN zypper -n install -y \
-  libglvnd \
-  libgomp1 \
-  libjpeg8 \
-  libpixman-1-0 \
-  libXdmcp6 \
-  libXfont2-2 \
-  libxkbcommon-x11-0 \
-  openssl \
-  perl \
-  x11-tools \
-  xauth \
-  xkbcomp \
-  xkeyboard-config && \
-  mkdir -p /etc/pki/tls/private
-
+# Cache repo updates, so that package changes don't trigger it on every build.
+RUN zypper refresh
 ARG KASMVNC_PACKAGE_DIR
 COPY $KASMVNC_PACKAGE_DIR/*.rpm /tmp
 RUN zypper install -y --allow-unsigned-rpm /tmp/*.rpm

builder/dockerfile.opensuse_15.rpm.build

@@ -14,7 +14,10 @@ RUN zypper -n install -y \
   tree \
   vim
 
+# Cache repo updates, so that spec changes don't trigger it on every build.
+RUN zypper refresh
 COPY opensuse/*.spec /tmp
+
 RUN zypper -n install $(grep BuildRequires /tmp/*.spec | cut -d' ' -f2 | xargs)
 
 RUN useradd -u 1000 -m -d /home/docker docker && \