SSH port-forwarding from within the Google Cloud Shell

Google provides a very useful tool especially for those I’m calling “cloud workers”: the Cloud Shell. This gives you access to a linux-shell for just whatever you do usually in a linux shell - directly from your browser.

From time to time I use the cloud shell as a starting-point to connect via ssh to other systems. Recently I noticed that tcp-port-forwarding via the outgoing ssh-connections doesn’t work out of the box: When trying to establish a port-forwarding (ssh user@targethost -L 8080:127.0.0.1:8080) the following error occurs:

bind: Cannot assign requested address

… and the port-forwarding doesn’t work.

The reason for this is simple - as always as you know it: The ssh-client tries to bind to the local ipv6-port. This is not supported in the cloud shell and therefore fails.

How to delete command lines from the bash history

And suddenly it happened again: I’ve typed sensitive information (at this time it was a password) into the command line.

And the shell kindly saved the typed commandline into its history. This way it wants to help me if I need the same command line later again. Great!

But what happens, if the system I’m working on isn’t under my full control? Imagine I’ve worked on a customer system …

Or what if someone later looks over my shoulder while I’m searching through my history?

The sensitive line needs to be removed!

• What’s the best way for doing this?
• How do we protect ourselves from this happening again later?

Generally speaking: You have two options to remove command lines from the bash history: first, by using the history command and second, by editing ~/.bash_history directly.