Thanks for your response stgraber.
I removed my custom settings, apply the default profile to my container, empty my subuid/subgid, and run the process from the link you send to me.
The result is strictly the same 
in the container, the directory is owned by nobody:nogroup (65534:65534).
What i’ve done after reset ?
printf “lxd:$(id -u):1\nroot:$(id -u):1\n” | sudo tee -a /etc/subuid
printf “lxd:$(id -g):1\nroot:$(id -g):1\n” | sudo tee -a /etc/subgid
So the subuid/subgid contains:
lxd:0:1
root:0:1
systemctl restart lxd
printf “uid $(id -u) 1000\ngid $(id -g) 1000” | lxc config set test raw.idmap -
result:
error: LXD doesn’t have a uid/gid allocation. In this mode, only privileged containers are supported.
So, as explained in top of the link, i edited subuid/subgid manually (excuse me…):
lxd:100000:1000000000
root:100000:1000000000
i done again :
systemctl restart lxd
printf “uid $(id -u) 1000\ngid $(id -g) 1000” | lxc config set test raw.idmap -
terminated without error.
finally done :
lxc restart MY-CONTAINER
And in the container, as noticed, the directory is owned by nobody.
Am i obliged to do “Per container maps” or “privileged container” ?
