Install ttrss from tar instead of git

Dockerfile

@@ -1,9 +1,11 @@
 FROM ubuntu
 MAINTAINER Christian Lück <christian@lueck.tv>
 
-RUN DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y \
-  nginx git supervisor php5-fpm php5-cli php5-curl php5-gd php5-json \
-  php5-pgsql php5-mysql && apt-get clean
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive apt-get install -y \
+        nginx supervisor php5-fpm php5-cli php5-curl php5-gd php5-json \
+        php5-pgsql php5-mysql \
+    && apt-get clean && rm -rf /var/lib/apt/lists/*
 
 # add ttrss as the only nginx site
 ADD ttrss.nginx.conf /etc/nginx/sites-available/ttrss
@@ -11,11 +13,15 @@ RUN ln -s /etc/nginx/sites-available/ttrss /etc/nginx/sites-enabled/ttrss
 RUN rm /etc/nginx/sites-enabled/default
 
 # install ttrss and patch configuration
-RUN git clone https://github.com/gothfox/Tiny-Tiny-RSS.git /var/www
+RUN mkdir /var/www \
+    && apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y curl --no-install-recommends && rm -rf /var/lib/apt/lists/* \
+    && curl -SL https://github.com/gothfox/Tiny-Tiny-RSS/archive/master.tar.gz | tar xvz -C /var/www --strip-components 1 \
+    && apt-get purge -y --auto-remove curl \
+    && chown www-data:www-data -R /var/www
+
 WORKDIR /var/www
 RUN cp config.php-dist config.php
 RUN sed -i -e "/'SELF_URL_PATH'/s/ '.*'/ 'http:\/\/localhost\/'/" config.php
-RUN chown www-data:www-data -R /var/www
 
 # expose only nginx HTTP port
 EXPOSE 80