[Qemu-devel] [PATCH 3/3] docker: debian-bootstrap.pre: print helpful message if DEB_ARCH/DEB_TYPE unset

[Sascha Silbe]

The debian-bootstrap image doesn't choose a default architecture and
distribution version, instead the user has to set both DEB_ARCH and
DEB_TYPE in the environment. Print a reasonably helpful message if
either of them isn't set instead of complaining about "qemu-" being
missing or erroring out because we cannot cd to the mirror URL.

Signed-off-by: Sascha Silbe <address@hidden>
---

I haven't figured out a good way to warn about qemu-user-* being
missing because EXECUTABLE isn't set. debian-bootstrap.pre runs before
docker.py copies the executable so I cannot check in
debian-bootstrap.pre whether the binfmt interpreter exists. The
EXECUTABLE environment variable needs to be set only when run via
make, so checking it in debian-bootstrap.pre is no good either. And an
additional docker-image-debian-bootstrap rule in the Makefile that
checks if EXECUTABLE is set would override the regular rule, not
enhance it.

 tests/docker/dockerfiles/debian-bootstrap.pre | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/docker/dockerfiles/debian-bootstrap.pre 
b/tests/docker/dockerfiles/debian-bootstrap.pre
index 5d9c8d5..2ae363f 100755
--- a/tests/docker/dockerfiles/debian-bootstrap.pre
+++ b/tests/docker/dockerfiles/debian-bootstrap.pre
@@ -15,6 +15,19 @@ exit_and_skip()
 if [ -z $FAKEROOT ]; then
     echo "Please install fakeroot to enable bootstraping"
     exit_and_skip
+
+fi
+
+if [ -z "${DEB_ARCH}" ]; then
+    echo "Please set DEB_ARCH to choose an architecture (e.g. armhf)"
+    exit_and_skip
+
+fi
+
+if [ -z "${DEB_TYPE}" ]; then
+    echo "Please set DEB_TYPE to a Debian archive name (e.g. testing)"
+    exit_and_skip
+
 fi
 
 # We check in order for
-- 
1.9.1