lxc-attach causing unprivileged containers run by non-root to immediately crash in Alpine 3.14
Following on from this report in the LXC forum: https://discuss.linuxcontainers.org/t/lxc-4-0-9-lxc-attach-cannot-allocate-memory/11171/6, this seems now to be an Alpine issue.
After upgrading to 3.14, the command lxc-attach -n <container> results in an error dump including the string "Out of memory":
lxc-attach: klystron: attach.c: lxc_attach: 1571 Out of memory - Failed to clone attached process
Upon checking the status of the container it is found to be not running. A trace of the command is attached below.
Retested using a snapshot of the previous, problem-free Alpine 3.13 installation, using the 4.0.9 lxc tools as distributed with Alpine 3.14, the problem is not reproducible; so the problem does not seem to be with lxc 4.0.9.