B OpenNebula/one#5086: Add fuse support (#541)

This commit solves issues with creating new VM images based on the
docker images inside a container environment.

If fuse2fs command is present then prefer its use instead of the default
mount command which will work only under root or otherwise privileged
user.

This commit solves the mounting issue inside the rootless container
environment.

Also add a new environment file to the oned supervisord service so we
can start oned process with some additional env. variables - notably
DOCKER_HOST.

Signed-off-by: Petr Ospalý <pospaly@opennebula.io>

share/pkgs/services/supervisor/centos8/scripts/opennebula.sh

@@ -40,6 +40,7 @@ msg "Database is running - continue"
 
 for envfile in \
     /var/run/one/ssh-agent.env \
+    /etc/sysconfig/oned \
     ;
 do
     if [ -f "$envfile" ] ; then

src/mad/sh/create_container_image.sh

@@ -46,7 +46,13 @@ esac
 #-------------------------------------------------------------------------------
 # Mount container disk image and untar rootfs contents to it
 #-------------------------------------------------------------------------------
-mount $tmp_dir/$id.raw $tmp_dir/$id
+
+# try first to mount with the fuse2fs command and if that fails fallback to the
+# regular mount
+if ! fuse2fs -o noexec,nodev,nosuid $tmp_dir/$id.raw $tmp_dir/$id >/dev/null 2>&1 ; then
+    mount -o noexec,nodev,nosuid $tmp_dir/$id.raw $tmp_dir/$id
+fi
+
 chown $USER:$GROUP $tmp_dir/$id
 tar $untar_options $tmp_dir/$id.$extension -C $tmp_dir/$id > /dev/null 2>&1
 

src/mad/sh/create_docker_image.sh

@@ -59,7 +59,13 @@ fi
 trap clean EXIT
 
 # Mount container disk image and untar rootfs contents to it
-mount -o noexec,nodev,nosuid $img_raw $dockerdir/mnt > /dev/null 2>&1
+
+# try first to mount with the fuse2fs command and if that fails fallback to the
+# regular mount
+if ! fuse2fs -o noexec,nodev,nosuid $img_raw $dockerdir/mnt >/dev/null 2>&1 ; then
+    mount -o noexec,nodev,nosuid $img_raw $dockerdir/mnt
+fi
+
 chmod o+w $dockerdir/mnt
 tar xpf $tarball -C $dockerdir/mnt > /dev/null 2>&1