在Alpine Docker容器应该如何安装openssh？

跑apk update第一。以下粘贴包含一个完整的示例：

ole@T:~$ docker run -it --rm alpine /bin/ash
/ # apk update
fetch http://dl-4.alpinelinux.org/alpine/v3.3/main/x86_64/APKINDEX.tar.gz
fetch http://dl-4.alpinelinux.org/alpine/v3.3/community/x86_64/APKINDEX.tar.gz
v3.3.1-97-g109077d [http://dl-4.alpinelinux.org/alpine/v3.3/main]
v3.3.1-59-g48b0368 [http://dl-4.alpinelinux.org/alpine/v3.3/community]
OK: 5853 distinct packages available
/ # apk add openssh
(1/3) Installing openssh-client (7.1_p2-r0)
(2/3) Installing openssh-sftp-server (7.1_p2-r0)
(3/3) Installing openssh (7.1_p2-r0)
Executing busybox-1.24.1-r7.trigger
OK: 8 MiB in 14 packages