[Libguestfs] [PATCH] Add simple parsing logic for hostname file.

There are some linux systems in the wild where the /etc/hostname file does not contain the configured hostname as sole line in that file. This file actually allows for comments [1] starting with "#" and the original logic would extract the comment line instead of the hostname on such systems. This patch fixes this by filtering out the comment lines and any empty lines. [1] https://www.freedesktop.org/software/systemd/man/hostname.html --- Please keep in mind that this is my first attempt at OCaml after taking a quick crash-course to get familiar with the language to produce this patch. Therefore, the patch may be very suboptimal and break guidelines, so please be forgiving :-) daemon/inspect_fs_unix.ml | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/daemon/inspect_fs_unix.ml b/daemon/inspect_fs_unix.ml index 63cb279d0..533ef71b2 100644 --- a/daemon/inspect_fs_unix.ml +++ b/daemon/inspect_fs_unix.ml @@ -556,11 +556,23 @@ and check_hostname_from_file filename = let chroot = let name = sprintf "check_hostname_from_file: %s" filename in Chroot.create ~name () in - - let hostname = Chroot.f chroot read_small_file filename in - match hostname with - | None | Some [] | Some [""] -> None - | Some (hostname :: _) -> Some hostname + try + let lines = Chroot.f chroot read_small_file filename in + let lines = match lines with + | None -> raise Not_found + | Some lines -> List.map String.trim lines in + let rec loop = function + | [] -> raise Not_found + | line :: _ when String.length line > 0 && + not (String.is_prefix line "#") -> + line + | _ :: lines -> + loop lines + in + let hostname = loop lines in + Some hostname + with + Not_found -> None (* Parse the hostname from /etc/sysconfig/network. This must be * called from the 'with_augeas' wrapper. Note that F18+ and -- 2.36.1