README: suggest disabling selinux

[dveeden]

Without disabling SELinux the containers can't read the volumes. It might be possible to change the SELinux configuration and/or file labels but it is advised to disable SELinux for now.

This was tested on CentOS 7.9.2009 with Docker compose v1.29.2 and Docker 1.13.1

[yahonda]

Thanks for the update. It definitely helps users who run Docker Compose on Linux. I think it needs to add some comments that this command is only available for Linux, not available on macOS.

% sw_vers
ProductName:    macOS
ProductVersion: 12.1
BuildVersion:   21C52
% sudo setenforce 0
sudo: setenforce: command not found
%

[dveeden]

@yahonda would something like this be ok?

diff --git a/README.md b/README.md
index edadaae..2802553 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@
 ```bash
 $ git clone https://github.com/pingcap/tidb-docker-compose.git
 $ cd tidb-docker-compose && docker-compose pull # Get the latest Docker images
-$ sudo setenforce 0
+$ sudo setenforce 0 # Only on Linux
 $ docker-compose up -d
 $ mysql -h 127.0.0.1 -P 4000 -u root

I assume this line is ok?

Note: It is recommended to disable SELinux.

As I'm not a macOS user I don't really know how Docker for Mac behaves.

[yahonda]

It looks good to me.

I'm also not so familiar with Docker for macOS, docker-compose up -d works by increasing memory and swap resource on macOS https://github.com/pingcap/tidb-docker-compose/issues/100#issuecomment-999227524