ReadFile is adapTed from ioutil.

WalkDirs looks for files in the given dir and returns a list of files in it usage for all files in the b0x: WalkDirs("", false).

WriteFile is adapTed from ioutil.

CTX is a context for webdav vfs.

FileClickhouseSQLTpl is "/clickhouse.sql.tpl".

FileMysqlSQLTpl is "/mysql.sql.tpl".

FS is a virtual memory file system.

Handler is used to server files through a http handler.

HTTP is the http file system.

HTTPFS implements http.FileSystem.