machine: hetzner: Fix deployment on smaller instances.

* gnu/machine/hetzner.scm (hetzner-machine-rescue-install-os): Avoid out of
disk space error by bind mounting /mnt/tmp/gnu/store to /gnu/store.
* tests/machine/hetzner.scm: Test with smaller instances.
* doc/guix.texi (Invoking guix deploy): Mention unsupported instance.

Change-Id: If8bfb6733de493b51813b3e82e255849192f7cba
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/gnu/machine/hetzner.scm b/gnu/machine/hetzner.scm
index 1d9a3f43857..bc8d2efbd34 100644
--- a/gnu/machine/hetzner.scm
+++ b/gnu/machine/hetzner.scm
@@ -551,6 +551,13 @@ chmod 700 /mnt/root/.ssh
 cp /root/.ssh/authorized_keys /mnt/root/.ssh/authorized_keys
 chmod 600 /mnt/root/.ssh/authorized_keys
 
+# Small instance don't have much disk space.  Bind mount the store of the
+# rescue system to the tmp directory of the new Guix system.
+mkdir -p /mnt/tmp/gnu/store
+mkdir -p /gnu/store
+mount --bind /mnt/tmp/gnu/store /gnu/store
+
+apt-get install guix --assume-yes
 cat > /tmp/guix/deploy/hetzner-os.scm << EOF
 (use-modules (gnu) (guix utils))
 (use-package-modules ssh)
@@ -605,7 +612,7 @@ fdisk -l /dev/sda"
      (format #f "#!/usr/bin/env bash
 set -eo pipefail
 apt-get update
-apt-get install guix cloud-initramfs-growroot --assume-yes"))
+apt-get install cloud-initramfs-growroot --assume-yes"))
     (format #t "successfully installed rescue system packages on '~a'\n" name)))
 
 (define (hetzner-machine-delete machine server)