The background is that there are at least two distributions with very
different host fs layouts. Those would be NixOS and GNU Guix.
For example, on NixOS, /lib/modules does not exist, it can instead
be found at /run/current-system/kernel-modules/lib/modules where
/run/current-system/kernel-modules is a symlink into /nix/store.
Within the modules directory, again on NixOS, there are more links
into the /nix store.
So to support alternate host fs layouts it is now possible to specify
the lib/modules host path and in addition specify extra mounts.
Signed-off-by: John Axel Eriksson <john@insane.se>
Previous code tried to interpret the string output as a `fmt.Sprintf`
string formatter, mangling `%` into `%!(MISSING)`, etc.
Thanks to go, I don't belive these are exploitable (unlike the similar
error in C).
Since this seemed to be a common error in the codebase, I did a quick
audit by visually inspecting the results of `git grep 'f([^"]'`. I
don't have a good suggestion for automated tests to prevent this in
future :(
Example error (look for `(MISSING)`):
```
E0927 05:31:07.618429 11227 driver-call.go:237] Failed to unmarshal output for command: unmount, output: "2018-09-27 05:31:07.191711 I | exec: Running command: df --type ceph /var/lib/kubelet/pods/95461479-c216-11e8-bcf0-02030782ac80/volumes/ceph.rook.io~rook/oe-scratch\n2018-09-27 05:46:43.808596 I | Filesystem 1K-blocks Used Available Use%!M(MISSING)ounted on\n2018-09-27 05:46:43.808659 I | 10.107.25.147:6790,10.109.173.79:6790,10.104.85.255:6790:/ 151678976 49410048 102268928 33%!/(MISSING)var/lib/kubelet/pods/95461479-c216-11e8-bcf0-02030782ac80/volumes/ceph.rook.io~rook/oe-scratch\n{\"status\":\"Success\"}\n", error: invalid character '-' after top-level value
```
Signed-off-by: Angus Lees <gus@inodes.org>
John Axel Eriksson
Angus Lees
travisn
Jared Watts