如何修复运行 redis:alpine Docker 镜像时出现的警告

如果我运行Redis：高山 https://hub.docker.com/_/redis/使用命令的 Docker 镜像

docker run redis:alpine

我看到几个警告：

1:C 08 May 08:29:32.308 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 3.2.8 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 1
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

1:M 08 May 08:29:32.311 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
1:M 08 May 08:29:32.311 # Server started, Redis version 3.2.8
1:M 08 May 08:29:32.311 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
1:M 08 May 08:29:32.311 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
1:M 08 May 08:29:32.311 * The server is now ready to accept connections on port 6379

我尝试使用以下方法修复前两个警告Dockerfile:

FROM redis:alpine
COPY somaxconn /proc/sys/net/core/somaxconn
COPY sysctl.conf /etc/sysctl.conf
CMD ["redis-server", "--appendonly", "yes"]

我的本地文件在哪里somaxconn包含单个条目511 and sysctl.conf包含行vm.overcommit_memory = 1。但是，当我构建和运行容器时，我仍然收到相同的警告。

我怎样才能摆脱这些警告？ （其中提到了这些问题https://www.techandme.se/performance-tips-for-redis-cache-server/ https://www.techandme.se/performance-tips-for-redis-cache-server/但那里描述的解决方案涉及修改rc.local https://www.raspberrypi.org/documentation/linux/usage/rc-local.md，似乎与 Raspberry Pi 有关）。

处理事情的方式不好: /proc是只读文件系统，要修改它，您可以在特权模式下运行 Docker，而不是在容器启动后对其进行修改。

如果在特权模式下运行容器，您可以使用以下命令禁用 THP：

# echo never > /sys/kernel/mm/transparent_hugepage/enabled
# echo never > /sys/kernel/mm/transparent_hugepage/defrag

合适的方式：确保运行较新版本的 Docker（如果需要，请升级）。run子命令具有 --sysctl 选项：

$ docker run -ti --sysctl net.core.somaxconn=4096 --rm redis:alpine /bin/sh
root@9e850908ddb7:/# sysctl net.core.somaxconn
net.core.somaxconn = 4096
...

很遗憾: vm.overcommit_memory目前不允许通过设置--sysctl参数同样适用于 THP (transparent_hugepage)，这是因为它们没有命名空间。因此，要修复 Linux 主机上运行的容器中的这些警告，您可以直接在主机上更改它们。这里是相关问题：

• #19 https://github.com/docker-library/redis/issues/19
• #55 https://github.com/docker-library/redis/issues/55

您不需要特权模式合适的方式方法。