无法从STDIN创buildDocker秘密

我试图根据Docker文档创buildDocker秘密：

$ echo | docker秘密创buildmy_secret –

并得到以下内容：

$ echo 'this is my secret' | docker secret create my-secret - Error reading content from "-": Incorrect function. 

这在ConEmu中的Docker Toolbox下运行：

 $ docker version Client: Version: 17.07.0-ce API version: 1.31 Go version: go1.8.3 Git commit: 8784753 Built: Tue Aug 29 17:41:05 2017 OS/Arch: windows/amd64 Server: Version: 17.09.0-ce API version: 1.32 (minimum version 1.12) Go version: go1.8.3 Git commit: afdb6d4 Built: Tue Sep 26 22:45:38 2017 OS/Arch: linux/amd64 Experimental: false 

该行为仅为STDIN选项显示，该命令适用于文件：

 $ docker secret create my_secret ./secret.txt ulec3yck5jpwywg6o7ptxnun7 $ openssl rand -base64 32 | docker secret create secure-secret - Error reading content from "-": Incorrect function. $ echo "mydatabasepassword" | docker secret create db_pass - Error reading content from "-": Incorrect function.