问题
CAP_IPC_LOCK 和 CAP_SYS_NICE 能力。该如何解决？
下面是缺少 CAP_SYS_NICE 能力时的日志消息示例：
docker run -d --name clickhouse-server \
--ulimit nofile=262144:262144 \
--network clickhouse-net \
-p 8123:8123 -p 9000:9000 -p 9009:9009 -p 9363:9363 \
clickhouse/clickhouse-server:23.2
2023.04.19 08:04:10.022720 [ 1 ] {} <Information> Application: It looks like the process has no CAP_IPC_LOCK capability, binary mlock will be disabled. It could happen due to incorrect ClickHouse package installation. You could resolve the problem manually with 'sudo setcap cap_ipc_lock=+ep /usr/bin/clickhouse'. Note that it will not work on 'nosuid' mounted filesystems.
2023.04.19 08:04:10.065860 [ 1 ] {} <Information> Application: It looks like the process has no CAP_SYS_NICE capability, the setting 'os_thread_priority' will have no effect. It could happen due to incorrect ClickHouse package installation. You could resolve the problem manually with 'sudo setcap cap_sys_nice=+ep /usr/bin/clickhouse'. Note that it will not work on 'nosuid' mounted filesystems.
答案
- 添加两个
--cap-add参数，为容器授予IPC_LOCK和SYS_NICE能力：
docker run -d --name clickhouse-server \
--cap-add=SYS_NICE \
--cap-add=IPC_LOCK \
--ulimit nofile=262144:262144 \
--network clickhouse-net \
-p 8123:8123 -p 9000:9000 -p 9009:9009 -p 9363:9363 \
clickhouse/clickhouse-server:23.2
- 使用以下命令检查这些能力在容器中是否可见：
apt-get update > /dev/null && apt-get install -y libcap2-bin > /dev/null && capsh --print
debconf: delaying package configuration, since apt-utils is not installed
WARNING: libcap needs an update (cap=40 should have a name).
Current: = cap_chown,cap_dac_override,cap_fowner,cap_fsetid,cap_kill,cap_setgid,cap_setuid,cap_setpcap,cap_net_bind_service,cap_net_raw,cap_ipc_lock,cap_sys_chroot,cap_sys_nice,cap_mknod,cap_audit_write,cap_setfcap+ep
Bounding set =cap_chown,cap_dac_override,cap_fowner,cap_fsetid,cap_kill,cap_setgid,cap_setuid,cap_setpcap,cap_net_bind_service,cap_net_raw,cap_ipc_lock,cap_sys_chroot,cap_sys_nice,cap_mknod,cap_audit_write,cap_setfcap
Ambient set =
Securebits: 00/0x0/1'b0
secure-noroot: no (unlocked)
secure-no-suid-fixup: no (unlocked)
secure-keep-caps: no (unlocked)
secure-no-ambient-raise: no (unlocked)
uid=0(root) euid=0(root)
gid=0(root)
groups=0(root)
Guessed mode: UNCERTAIN (0)
- 手动为 ClickHouse 设置这两种能力
setcap "cap_ipc_lock=+ep cap_sys_nice=+ep" /usr/bin/clickhouse
- 检查这些能力是否已生效。
getcap -v /usr/bin/clickhouse
/usr/bin/clickhouse = cap_ipc_lock,cap_sys_nice+ep
- 重启 ClickHouse server 后，这些日志消息应该不会再出现。
有关更多信息，请参阅这篇关于 Linux 能力的文章。