openssh: allow to override OpenSSL HostKeys when read-only-rootfs

With these changes it is possible to have a .bbappend that
- sets SYSCONFDIR to some persistent storage
- modifies SYSCONFDIR/sshd_config to use ssh host keys from
  the (writable) sysconfdir

(From OE-Core rev: 79c7c8342859306750f0af17210a183fdc543caf)

Signed-off-by: André Draszik <adraszik@tycoint.com>
Reviewed-by: Stephane Ayotte <sayotte@tycoint.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

(cherry picked from commit 106b59d9f96f70d133fa1421091ad280d27a5b6a)
Signed-off-by: André Draszik <adraszik@tycoint.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/meta/classes/rootfs-postcommands.bbclass b/meta/classes/rootfs-postcommands.bbclass
index 2503d89e28..4b91972ce7 100644
--- a/meta/classes/rootfs-postcommands.bbclass
+++ b/meta/classes/rootfs-postcommands.bbclass
@@ -91,10 +91,10 @@ read_only_rootfs_hook () {
         # and the keys under /var/run/ssh.
         if [ -d ${IMAGE_ROOTFS}/etc/ssh ]; then
                 if [ -e ${IMAGE_ROOTFS}/etc/ssh/ssh_host_rsa_key ]; then
-                        echo "SYSCONFDIR=/etc/ssh" >> ${IMAGE_ROOTFS}/etc/default/ssh
+                        echo "SYSCONFDIR=\${SYSCONFDIR:-/etc/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
                         echo "SSHD_OPTS=" >> ${IMAGE_ROOTFS}/etc/default/ssh
                 else
-                        echo "SYSCONFDIR=/var/run/ssh" >> ${IMAGE_ROOTFS}/etc/default/ssh
+                        echo "SYSCONFDIR=\${SYSCONFDIR:-/var/run/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
                         echo "SSHD_OPTS='-f /etc/ssh/sshd_config_readonly'" >> ${IMAGE_ROOTFS}/etc/default/ssh
                 fi
         fi