[lxc-devel] [PATCH] lxc-download: Detect unpriv created by real root

[Stéphane Graber]

This adds yet another case in the in_userns function detecting the case
where an unprivileged container is created by the real uid 0, in which
case we want to share the system wide cache but still use the
unprivileged templates and unpack method.

Signed-off-by: Stéphane Graber <stgraber at ubuntu.com>
---
 templates/lxc-download.in | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/templates/lxc-download.in b/templates/lxc-download.in
index 53b06e7..732bd97 100644
--- a/templates/lxc-download.in
+++ b/templates/lxc-download.in
@@ -142,8 +142,11 @@ gpg_validate() {
 
 in_userns() {
     [ -e /proc/self/uid_map ] || { echo no; return; }
-    line=$(awk '{ print $1 " " $2 " " $3 }' /proc/self/uid_map)
-    [ "$line" = "0 0 4294967295" ] && { echo no; return; }
+    awk '{ print $1 " " $2 " " $3 }' /proc/self/uid_map | while read line; do
+        [ "$line" = "0 0 4294967295" ] && { echo no; return; }
+        echo $line | grep -q " 0 1$" && { echo userns-root; return; }
+    done
+
     [ "$(cat /proc/self/uid_map)" = "$(cat /proc/1/uid_map)" ] && \
         { echo userns-root; return; }
     echo yes
-- 
1.9.0