Documenting usage of container-shell command restrictions in its manpage.

Signed-off-by: Daniel Baumann <daniel.baumann@open-infrastructure.net>

1 files changed, 33 insertions, 0 deletions

diff --git a/share/man/container-shell.1.txt b/share/man/container-shell.1.txt
index 6d792b8..10f4f97 100644
--- a/share/man/container-shell.1.txt
+++ b/share/man/container-shell.1.txt
@@ -53,6 +53,39 @@ All container commands are available, see container(1). Additionally, the follow
 *logout*, *exit:*::
 	exits container-shell.
 
+USAGE
+-----
+Although the container-shell can be started from a running system like any other program, the main intend is to use the
+container-shell via SSH in order to give otherwise unprivileged users the possibility to manage containers without
+giving them a normal shell login on the container server.
+
+For usage over SSH a unprivileged user should be created:
+
+  sudo adduser --gecos "container-tools,,," \
+	--home /var/lib/container-tools/container-shell \
+	--shell /usr/bin/container-shell
+
+The container-shell can then be allowed for specific SSH keys via /var/ib/container-tools/container-shell/.ssh/authorized_keys like so:
+
+  command="/usr/bin/container-shell",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa [...]
+
+
+RESTRICTED SHELL
+----------------
+The container-shell by default grants any user that has access to it to use all available container commands.
+
+Through two corresponding environment variables users can be allowed or disallowed to use specific container commands.
+In connection with SSH this makes it possible to grant certain SSH keys (and by that, users) privileges to operate container
+servers without having to give them root access, a login shell at all and prevents them from doing things they are not trusted to do.
+
+Example (blacklisting): In order to allow all commands except for removing and stopping containers, the following variable can be used:
+
+  command="CONTAINER_COMMANDS_DISABLE='remove stop' /usr/bin/container-shell",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa [...]
+
+Example (whitelisting): The other way around works too. To disallow all commands except for listing containers and showing the container-tools version, the following variable can be used:
+
+  command="CONTAINER_COMMANDS_ENABLE='list version' /usr/bin/container-shell",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ssh-rsa [...]
+
 
 SEE ALSO
 --------