ensure compat

Author: johnstcn

images/base/ubuntu.Dockerfile

@@ -39,6 +39,9 @@ RUN apt-get update && \
     wget \
     rsync
 
+# Compat: on non-armv7 architectures, install `software-properties-common`
+RUN [[ "$(dpkg --print-architecture)" != "armhf" ]] && apt-get install --yes software-properties-common || echo "WARN: Skipping software-properties-common installation on armhf"
+
 # Install latest Git using their official PPA
 # Note: due to a dependency issue with the armv7 `software-properties-common` package,
 # we can't use `add-apt-repository` here. Instead, we'll add the Git PPA