数据卷相对路径必须以 . 或 .. 开头，否则会被认为是卷名称，由于存在 “/” 会提示：ERROR: haproxy/haproxy.cfg includes invalid characters for a local volume name, only [a-zA-Z0-9][a-zA-Z0-9_.-] are allowed
参考来源：https://docs.docker.com/compose/compose-file/
You can mount a relative path on the host, which will expand relative to the directory of the Compose configuration file being used. Relative paths should always begin with . or ...
