我试图理解它lxc.id_map的工作原理，但我的问题是，我甚至无法重现默认设置 UID 映射。似乎无论lxc.id_map我设置什么，它总是会返回错误“无法设置 ID 映射。”。
我使用所有默认设置对全新安装的 16.04 64 位版本进行了下列测试。
我以非 root 用户身份创建了一个新的容器：
lxc launch images:ubuntu/xenial/amd64 u1
似乎容器以 root uid=165536 启动：
ggyimesi@lxctest:~$ ps aux | grep init
root 1 0.2 0.1 119756 6076 ? Ss 20:43 0:01 /sbin/init splash
165536 5628 0.0 0.1 37008 5120 ? Ss 20:50 0:00 /sbin/init
ggyimesi 5951 0.0 0.0 21292 1032 pts/17 S+ 20:57 0:00 grep --color=auto init
因此我停止了容器并编辑了配置，lxc config edit u1添加lxc.id_map如下行：
architecture: x86_64
config:
raw.lxc: |
lxc.id_map = u 0 165536 65536
lxc.id_map = g 0 165536 65536
volatile.base_image: bff1ac73dada477000de5efbbd84ca12b0761fd4100f13ee39f9345553edb2f3
volatile.eth0.hwaddr: 00:16:3e:e9:ea:b0
volatile.idmap.base: "0"
volatile.idmap.next: '[{"Isuid":true,"Isgid":false,"Hostid":165536,"Nsid":0,"Maprange":65536},{"Isuid":false,"Isgid":true,"Hostid":165536,"Nsid":0,"Maprange":65536}]'
volatile.last_state.idmap: '[{"Isuid":true,"Isgid":false,"Hostid":165536,"Nsid":0,"Maprange":65536},{"Isuid":false,"Isgid":true,"Hostid":165536,"Nsid":0,"Maprange":65536}]'
volatile.last_state.power: RUNNING
devices:
root:
path: /
type: disk
ephemeral: false
profiles:
- default
现在容器启动失败：
ggyimesi@lxctest:~$ lxc start u1
error: Error calling 'lxd forkstart u1 /var/lib/lxd/containers /var/log/lxd/u1/lxc.conf': err='exit status 1'
lxc 20170309200441.616 ERROR lxc_cgfsng - cgroups/cgfsng.c:create_path_for_hierarchy:1306 - Path "/sys/fs/cgroup/systemd//lxc/u1" already existed.
lxc 20170309200441.616 ERROR lxc_cgfsng - cgroups/cgfsng.c:cgfsng_create:1363 - No such file or directory - Failed to create /sys/fs/cgroup/systemd//lxc/u1: No such file or directory
lxc 20170309200441.759 ERROR lxc_start - start.c:lxc_spawn:1171 - Failed to set up id mapping.
lxc 20170309200441.119 ERROR lxc_start - start.c:__lxc_start:1346 - Failed to spawn container "u1".
lxc 20170309200441.643 ERROR lxc_conf - conf.c:run_buffer:405 - Script exited with status 1.
lxc 20170309200441.643 ERROR lxc_start - start.c:lxc_fini:546 - Failed to run lxc.hook.post-stop for container "u1".
lxc 20170309200441.645 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.645 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/systemd//lxc/u1-1
lxc 20170309200441.649 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.649 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/net_cls//lxc/u1-1
lxc 20170309200441.652 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.652 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/perf_event//lxc/u1-1
lxc 20170309200441.654 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.654 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/cpu//lxc/u1-1
lxc 20170309200441.655 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.656 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/devices//lxc/u1-1
lxc 20170309200441.657 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.657 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/blkio//lxc/u1-1
lxc 20170309200441.659 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.659 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/hugetlb//lxc/u1-1
lxc 20170309200441.661 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.661 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/pids//lxc/u1-1
lxc 20170309200441.662 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.662 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/cpuset//lxc/u1-1
lxc 20170309200441.664 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.664 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/memory//lxc/u1-1
lxc 20170309200441.666 ERROR lxc_conf - conf.c:userns_exec_1:4453 - Error setting up child mappings
lxc 20170309200441.666 ERROR lxc_cgfsng - cgroups/cgfsng.c:recursive_destroy:1270 - Error destroying /sys/fs/cgroup/freezer//lxc/u1-1
Try `lxc info --show-log u1` for more info
也许我遗漏了什么，但这不应该是默认设置吗？也就是说，容器应该像以前一样启动？lxc.id_map从配置中删除这些行可以使容器启动时没有任何错误。
有人能指出我为什么上述配置不起作用的正确方向吗？