Ensure docker cache fails if git repositories change

ggsn-test/Dockerfile

@@ -1,8 +1,11 @@
 FROM	debian-stretch-titan
 
-RUN	git clone git://git.osmocom.org/osmo-ttcn3-hacks.git && \
-	mkdir /root/projects && (cd /root/projects && ln -sf / git) && \
-	cd osmo-ttcn3-hacks/ggsn_tests && \
+RUN	mkdir /root/projects && (cd /root/projects && ln -sf / git)
+RUN	git clone git://git.osmocom.org/osmo-ttcn3-hacks.git
+
+ADD	http://git.osmocom.org/osmo-ttcn3-hacks/commit /tmp/commit
+RUN	cd osmo-ttcn3-hacks/ggsn_tests && \
+	git pull && \
 	./gen_links.sh && \
 	./regen_makefile.sh && \
 	make compile && \

m3ua-test/Dockerfile

@@ -2,8 +2,10 @@ FROM sigtran-tests
 
 MAINTAINER Harald Welte <laforge@gnumonks.org>
 
-RUN	cd /tmp && git clone https://github.com/nplab/m3ua-testtool && \
-	cd m3ua-testtool && \
+RUN	cd /tmp && git clone https://github.com/nplab/m3ua-testtool
+ADD	http://git.osmocom.org/nplab/m3ua-testtool/commit /tmp/commit
+RUN	cd /tmp/m3ua-testtool && \
+	git pull && \
 	cc -o runm3uatest runm3uatest.c && \
 	cp runm3uatest /usr/local/bin/
 

osmo-ggsn-master/Dockerfile

@@ -14,9 +14,11 @@ RUN	apt-get update && apt-get install -y \
 
 WORKDIR	/tmp
 
-RUN	git clone git://git.osmocom.org/openggsn.git && \
-	cd openggsn && \
-	git checkout laforge/osmo-ggsn && \
+ARG	timestamp=invalid
+RUN	git clone git://git.osmocom.org/openggsn.git
+ADD	http://git.osmocom.org/openggsn/commit/?h=laforge/osmo-ggsn /tmp/commit
+RUN	cd openggsn && \
+	git checkout -f laforge/osmo-ggsn && \
 	autoreconf -fi && \
 	./configure && \
 	make -j8 install && \

osmo-stp-master/Dockerfile

@@ -15,8 +15,10 @@ RUN	apt-get update && apt-get install -y \
 
 WORKDIR	/tmp
 
-RUN	git clone git://git.osmocom.org/libosmo-sccp.git && \
-	cd libosmo-sccp && \
+RUN	git clone git://git.osmocom.org/libosmo-sccp.git
+ADD	http://git.osmocom.org/libosmo-sccp/commit /tmp/commit
+RUN	cd libosmo-sccp && \
+	git pull && \
 	autoreconf -fi && \
 	./configure && \
 	make -j8 install && \

sua-test/Dockerfile

@@ -7,8 +7,10 @@ COPY	*.patch /tmp/
 RUN	git config --global user.email "nobody@localhost" && \
 	git config --global user.name "Docker Container"
 
-RUN	cd /tmp && git clone https://github.com/nplab/sua-testtool && \
-	cd sua-testtool && \
+RUN	cd /tmp && git clone https://github.com/nplab/sua-testtool
+ADD	http://git.osmocom.org/nplab/sua-testtool/commit /tmp/commit
+RUN	cd /tmp/sua-testtool && \
+	git pull && \
 	git am /tmp/*.patch && \
 	cc -o run-sua-test run-sua-test.c && \
 	cp run-sua-test /usr/local/bin/