[etherpad-web/oscp-backend] Clone the theme branch to skins directory

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit 315cd770462d346a904aac076efd0bec6f447d24
Author: Bartłomiej Piotrowski <bpiotrowski gnome org>
Date:   Wed May 20 11:44:15 2020 +0200

    Clone the theme branch to skins directory

 Dockerfile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/Dockerfile b/Dockerfile
index 98710bd..c5f4172 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ ENV NODE_ENV production
 
 RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-    ca-certificates curl unzip mariadb-client libreoffice && \
+    ca-certificates curl unzip mariadb-client libreoffice git && \
     rm -r /var/lib/apt/lists/* /var/cache/apt/*
 RUN update-ca-certificates
 
@@ -16,6 +16,7 @@ RUN cd /opt && curl -SL \
 
 RUN groupadd etherpad -g 1000180000  && \
     useradd etherpad -g 1000180000 -u 1000180000 -G etherpad -r -l -M -d /opt/etherpad && \
+    git clone --single-branch --branch theme --depth 1 https://gitlab.gnome.org/Infrastructure/etherpad-web 
/opt/etherpad/src/static/skins/gnome && \
     chown -R etherpad:etherpad /opt/etherpad
 
 ADD entrypoint.sh /entrypoint.sh