docker: Support showing environment information

Add a make variable SHOW_ENV. When it's set to non empty, print the
package information and environment variables.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1474429768-25027-8-git-send-email-famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>

tests/docker/Makefile.include

@@ -117,7 +117,7 @@ docker-run-%: docker-qemu-src
 				$(if $(DEBUG),-i,--net=none) \
 				-e TARGET_LIST=$(TARGET_LIST) \
 				-e EXTRA_CONFIGURE_OPTS=$(EXTRA_CONFIGURE_OPTS) \
-				-e V=$V -e J=$J -e DEBUG=$(DEBUG)\
+				-e V=$V -e J=$J -e DEBUG=$(DEBUG) -e SHOW_ENV=$(SHOW_ENV)\
 				-e CCACHE_DIR=/var/tmp/ccache \
 				-v $$(readlink -e $(DOCKER_SRC_COPY)):/var/tmp/qemu:z$(COMMA)ro \
 				-v $(DOCKER_CCACHE_DIR):/var/tmp/ccache:z \

tests/docker/run

@@ -40,6 +40,17 @@ for p in dtc pixman; do
     fi
 done
 
+if test -n "$SHOW_ENV"; then
+    if test -f /packages.txt; then
+        echo "Packages installed:"
+        cat /packages.txt
+        echo
+    fi
+    echo "Environment variables:"
+    env
+    echo
+fi
+
 export QEMU_SRC="$TEST_DIR/src"
 
 cd "$QEMU_SRC/tests/docker"