Merge branch 'master' into master

image/Dockerfile

@@ -1,4 +1,5 @@
-FROM ubuntu:18.04
+ARG BASE_IMAGE=ubuntu:18.04
+FROM $BASE_IMAGE
 MAINTAINER Phusion <info@phusion.nl>
 
 COPY . /bd_build

image/cleanup.sh

@@ -9,7 +9,7 @@ rm -rf /tmp/* /var/tmp/*
 rm -rf /var/lib/apt/lists/*
 
 # clean up python bytecode
-find / -name *.pyc -delete
-find / -name *__pycache__* -delete
+find / -mount -name *.pyc -delete
+find / -mount -name *__pycache__* -delete
 
 rm -f /etc/ssh/ssh_host_*

image/prepare.sh

@@ -41,7 +41,16 @@ $minimal_apt_get_install software-properties-common
 apt-get dist-upgrade -y --no-install-recommends -o Dpkg::Options::="--force-confold"
 
 ## Fix locale.
-$minimal_apt_get_install language-pack-en
+case $(lsb_release -is) in
+  Ubuntu)
+    $minimal_apt_get_install language-pack-en
+    ;;
+  Debian)
+    $minimal_apt_get_install locales locales-all
+    ;;
+  *)
+    ;;
+esac
 locale-gen en_US
 update-locale LANG=en_US.UTF-8 LC_CTYPE=en_US.UTF-8
 echo -n en_US.UTF-8 > /etc/container_environment/LANG