我有一个（以前可以正常工作的）OpenResty logrotate 设置，它是从以前的 Ubuntu 18.04 安装中获取的。然而，logrotate.service 现在失败并出现此错误...
error: error renaming /usr/local/openresty/nginx/logs/access.log.60.zst
to /usr/local/openresty/nginx/logs/access.log.61.zst: Read-only file system
... 我很难理解为什么。新机器运行的是 Ubuntu 20.04，但我不明白为什么在这种情况下这会有所不同。
首先，这是配置：
$ cat /etc/logrotate.d/custom-openresty
/usr/local/openresty/nginx/logs/access.log
/usr/local/openresty/nginx/logs/error.log
{
daily
rotate 60
maxsize 1G
missingok
notifempty
compress
compresscmd /usr/bin/zstd
uncompresscmd /usr/bin/unzstd
compressoptions -9 --long -T1
compressext .zst
delaycompress
sharedscripts
postrotate
test ! -f /usr/local/openresty/nginx/logs/nginx.pid || kill -USR1 `cat /usr/local/openresty/nginx/logs/nginx.pid`
endscript
}
/etc/logrotate.conf保持不变，如下所示：
# see "man logrotate" for details
# rotate log files weekly
weekly
# use the adm group by default, since this is the owning group
# of /var/log/syslog.
su root adm
# keep 4 weeks worth of backlogs
rotate 4
# create new (empty) log files after rotating old ones
create
# use date as a suffix of the rotated file
#dateext
# uncomment this if you want your log files compressed
#compress
# packages drop log rotation information into this directory
include /etc/logrotate.d
# system-specific logs may be also be configured here.
以下是我的文件的状态（我希望access.log.1在 logrotate 运行后获得）：
$ ls -alhg /usr/local/openresty/nginx/logs/
total 10G
drwxr-xr-x 2 root 4.0K Sep 16 20:04 .
drwxr-xr-x 18 root 4.0K Sep 16 19:42 ..
-rw-r--r-- 1 root 10G Sep 16 19:56 access.log
-rw-r--r-- 1 root 5.5K Sep 16 19:56 error.log
但是，logrotate.service 失败并出现以下错误：
~$ systemctl status logrotate.service
● logrotate.service - Rotate log files
Loaded: loaded (/lib/systemd/system/logrotate.service; static; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2020-09-16 20:11:32 UTC; 4min 32s ago
TriggeredBy: ● logrotate.timer
Docs: man:logrotate(8)
man:logrotate.conf(5)
Process: 27403 ExecStart=/usr/sbin/logrotate /etc/logrotate.conf (code=exited, status=1/FAILURE)
Main PID: 27403 (code=exited, status=1/FAILURE)
$ sudo journalctl --unit logrotate.service
Sep 16 20:11:32 fetcher-scheduler systemd[1]: Starting Rotate log files...
Sep 16 20:11:32 fetcher-scheduler logrotate[27403]: error: error renaming /usr/local/openresty/nginx/logs/access.log.60.zst to /usr/local/openresty/nginx/logs/access.log.61.zst: Read-only file system
Sep 16 20:11:32 fetcher-scheduler systemd[1]: logrotate.service: Main process exited, code=exited, status=1/FAILURE
Sep 16 20:11:32 fetcher-scheduler systemd[1]: logrotate.service: Failed with result 'exit-code'.
Sep 16 20:11:32 fetcher-scheduler systemd[1]: Failed to start Rotate log files.
当我以 root 身份在调试模式下运行它（不使用 systemd）时，我得到以下输出：
# logrotate -v -d /etc/logrotate.d/custom-openresty
reading config file /etc/logrotate.d/custom-openresty
compress_prog is now /usr/bin/zstd
uncompress_prog is now /usr/bin/unzstd
compress_options is now -9 --long -T1
compress_ext is now .zst
Reading state from file: /var/lib/logrotate/status
Allocating hash table for state file, size 64 entries
Creating new state
Creating new state
...
Creating new state
Handling 1 logs
rotating pattern: /usr/local/openresty/nginx/logs/access.log
/usr/local/openresty/nginx/logs/error.log
after 1 days (60 rotations)
empty log files are not rotated, log files >= 1073741824 are rotated earlier, old logs are removed
considering log /usr/local/openresty/nginx/logs/access.log
Now: 2020-09-16 20:24
Last rotated at 2020-09-16 20:11
log needs rotating
considering log /usr/local/openresty/nginx/logs/error.log
Now: 2020-09-16 20:24
Last rotated at 2020-09-16 19:00
log does not need rotating (log has been rotated at 2020-9-16 19:0, that is not day ago yet)
rotating log /usr/local/openresty/nginx/logs/access.log, log->rotateCount is 60
dateext suffix '-20200916'
glob pattern '-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
previous log /usr/local/openresty/nginx/logs/access.log.1 does not exist
renaming /usr/local/openresty/nginx/logs/access.log.60.zst to /usr/local/openresty/nginx/logs/access.log.61.zst (rotatecount 60, logstart 1, i 60),
renaming /usr/local/openresty/nginx/logs/access.log.59.zst to /usr/local/openresty/nginx/logs/access.log.60.zst (rotatecount 60, logstart 1, i 59),
...
/logs/access.log.3.zst (rotatecount 60, logstart 1, i 2),
renaming /usr/local/openresty/nginx/logs/access.log.1.zst to /usr/local/openresty/nginx/logs/access.log.2.zst (rotatecount 60, logstart 1, i 1),
renaming /usr/local/openresty/nginx/logs/access.log.0.zst to /usr/local/openresty/nginx/logs/access.log.1.zst (rotatecount 60, logstart 1, i 0),
log /usr/local/openresty/nginx/logs/access.log.61.zst doesn't exist -- won't try to dispose of it
renaming /usr/local/openresty/nginx/logs/access.log to /usr/local/openresty/nginx/logs/access.log.1
running postrotate script
running script with arg /usr/local/openresty/nginx/logs/access.log
/usr/local/openresty/nginx/logs/error.log
: "
test ! -f /usr/local/openresty/nginx/logs/nginx.pid || kill -USR1 `cat /usr/local/openresty/nginx/logs/nginx.pid`
"
对我来说，一切看起来都很正常。如果我运行它，它也会起作用：
# logrotate -v /etc/logrotate.d/custom-openresty
reading config file /etc/logrotate.d/custom-openresty
compress_prog is now /usr/bin/zstd
uncompress_prog is now /usr/bin/unzstd
compress_options is now -9 --long -T1
compress_ext is now .zst
Reading state from file: /var/lib/logrotate/status
Allocating hash table for state file, size 64 entries
Creating new state
...
Creating new state
Handling 1 logs
rotating pattern: /usr/local/openresty/nginx/logs/access.log
/usr/local/openresty/nginx/logs/error.log
after 1 days (60 rotations)
empty log files are not rotated, log files >= 1073741824 are rotated earlier, old logs are removed
considering log /usr/local/openresty/nginx/logs/access.log
Now: 2020-09-16 20:26
Last rotated at 2020-09-16 20:11
log needs rotating
considering log /usr/local/openresty/nginx/logs/error.log
Now: 2020-09-16 20:26
Last rotated at 2020-09-16 19:00
log does not need rotating (log has been rotated at 2020-9-16 19:0, that is not day ago yet)
rotating log /usr/local/openresty/nginx/logs/access.log, log->rotateCount is 60
dateext suffix '-20200916'
glob pattern '-[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]'
previous log /usr/local/openresty/nginx/logs/access.log.1 does not exist
renaming /usr/local/openresty/nginx/logs/access.log.60.zst to /usr/local/openresty/nginx/logs/access.log.61.zst (rotatecount 60, logstart 1, i 60),
old log /usr/local/openresty/nginx/logs/access.log.60.zst does not exist
...
old log /usr/local/openresty/nginx/logs/access.log.2.zst does not exist
renaming /usr/local/openresty/nginx/logs/access.log.1.zst to /usr/local/openresty/nginx/logs/access.log.2.zst (rotatecount 60, logstart 1, i 1),
old log /usr/local/openresty/nginx/logs/access.log.1.zst does not exist
renaming /usr/local/openresty/nginx/logs/access.log.0.zst to /usr/local/openresty/nginx/logs/access.log.1.zst (rotatecount 60, logstart 1, i 0),
old log /usr/local/openresty/nginx/logs/access.log.0.zst does not exist
log /usr/local/openresty/nginx/logs/access.log.61.zst doesn't exist -- won't try to dispose of it
renaming /usr/local/openresty/nginx/logs/access.log to /usr/local/openresty/nginx/logs/access.log.1
running postrotate script
没有错误，最终access.log.1按预期创建：
# ls -algh /usr/local/openresty/nginx/logs/
total 10G
drwxr-xr-x 2 root 4.0K Sep 16 20:26 .
drwxr-xr-x 18 root 4.0K Sep 16 19:42 ..
-rw-r--r-- 1 root 10G Sep 16 19:56 access.log.1
-rw-r--r-- 1 root 5.5K Sep 16 19:56 error.log
请注意，它说的是...
log /usr/local/openresty/nginx/logs/access.log.61.zst
doesn't exist -- won't try to dispose of it
... 而不是error renaming ... Read-only file system（正如logrotate.service）
为什么以root身份手动运行时可以运行，但通过logrotate.service执行时会失败？
我没有对 做任何更改logrotate.service。为了完整起见，下面是单元文件：
$ systemctl cat logrotate.service
# /lib/systemd/system/logrotate.service
[Unit]
Description=Rotate log files
Documentation=man:logrotate(8) man:logrotate.conf(5)
ConditionACPower=true
[Service]
Type=oneshot
ExecStart=/usr/sbin/logrotate /etc/logrotate.conf
# performance options
Nice=19
IOSchedulingClass=best-effort
IOSchedulingPriority=7
# hardening options
# details: https://www.freedesktop.org/software/systemd/man/systemd.exec.html
# no ProtectHome for userdir logs
# no PrivateNetwork for mail deliviery
# no ProtectKernelTunables for working SELinux with systemd older than 235
# no MemoryDenyWriteExecute for gzip on i686
PrivateDevices=true
PrivateTmp=true
ProtectControlGroups=true
ProtectKernelModules=true
ProtectSystem=full
RestrictRealtime=true
现在我已经没有选择了。任何帮助解决问题的帮助都将不胜感激。
答案1
我觉得我找到了。logrotate 文件不是问题所在。
相反，这是由 systemd 单元文件中的强化功能引起的。在我禁用ProtectSystem=full强化选项后，它就起作用了。原因是 logrotate 必须对/usr目录进行操作，如果启用该选项，则该目录为只读。
来自文档在ProtectSystem=
采用布尔参数或特殊值“full”或“strict”。如果为真，则将 /usr 和引导加载程序目录（/boot 和 /efi）挂载为该单元调用的进程的只读形式。如果设置为“full”，/etc 目录也会以只读方式挂载。如果设置为“strict”，则整个文件系统层次结构都会以只读方式挂载，但 API 文件系统子树 /dev、/proc 和 /sys 除外（使用 PrivateDevices=、ProtectKernelTunables=、ProtectControlGroups= 保护这些目录）。此设置可确保禁止对服务进行任何供应商提供的操作系统（以及可选的配置和本地挂载）的修改。建议为所有长期运行的服务启用此设置，除非它们涉及系统更新或需要以其他方式修改操作系统。如果使用此选项，则可以使用 ReadWritePaths= 排除特定目录的只读设置。如果设置了 DynamicUser=，则隐含此设置。此设置无法确保在所有情况下都受到保护。通常，它具有与 ReadOnlyPaths= 相同的限制，请参见下文。默认为关闭。
为了正确修复它，我现在添加了以下行/lib/systemd/system/logrotate.service：
ReadWritePaths=/usr/local/openresty/nginx/logs
然后ProtectSystem=full将除日志所在目录之外的所有内容都挂载为只读。现在，只读错误消失了：
# systemctl daemon-reload && systemctl start logrotate
(completed successfully without output)
我猜想，我从未在 Ubuntu 18.04 上遇到过这个问题，因为强化选项还不是默认选项。Ubuntu 20.04 现在有了这个功能，但我不知道它们是在哪个 Ubuntu 版本中首次引入的。
答案2
很高兴找到我遇到的相同问题。编辑 nginx.conf 以记录到不同的目录（例如公共的 /var/log/nginx）也是一种可行的替代方法。