VBoxManage – How to Pass Shell Arguments with VBoxManage Guestcontrol

bashcommand lineguest-additionsscriptsvirtualbox

I run a command from the host machine on the guest machine (both Ubuntu) as

VBoxManage guestcontrol Ubuntu1 run --exe "script.sh" --username xx --password xx --wait-stdout

where the shell script on the guest machine is as

#!/bin/bash
echo $1

How can I pass the argument 1 while executing the shell script?

I assumed it should work as

run --exe "script.sh arg1"

but it does not.

Best Answer

SSH

We can run an application on a virtual guest with an SSH session from the host to this machine. However this requires that networking was enabled, and that openssh-server was installed an runs on the guest machine.

VBoxManage guestcontrol

As an alternative we can use built-in features of Virtual Box to execute a program on a running guest VM. This can be done with VBoxManage guestcontrol.

The example line below will just run ls on the virtual machine's root:

VBoxManage --nologo guestcontrol "<vm_name>" run --exe "/bin/ls" --username <guestuser> --password <password> --wait-stdout

Running a graphical application on the guest requires us to define the DISPLAY environment variable to the guest with the option --putenv. Next example will run and open gedit on the guest:

VBoxManage --nologo guestcontrol "<vm_name" run --exe "/usr/bin/gedit" --username <guestuser> --password <password> --putenv "DISPLAY=:0" --wait-stdout

We can also pass options to open a program. Next example will open a file vmtest in the guest gedit:

VBoxManage --nologo guestcontrol "vm_name" run --exe "/usr/bin/gedit" --username <guestuser> --password <password> --putenv "DISPLAY=:0" --wait-stdout -- gedit/arg0 vmtest

Options and arguments are separated from the command with -- as can best be seen in below example of a script from the host.

Example host script

Below script will play an example.ogg file using paplay in a guest machine when run on the host. Replace the variables with appropriate values.

#!/bin/bash

VM_NAME=myvm
VM_USER=takkat
VM_PASSWD=topsecret
VM_EXEC=paplay
VM_EXEC_PATH=/usr/bin/paplay
VM_ARGS=/home/takkat/Music/example.ogg

VBoxManage --nologo guestcontrol $VM_NAME run --exe $VM_EXEC_PATH \
--username $VM_USER --password $VM_PASSWD --wait-stdout \
-- {$VM_EXEC}/arg0 $VM_ARGS

Related Solutions

Ubuntu – Why script with /bin/bash is working, with /bin/sh not

It's because Bash behaves differently when $0 is sh.

From Bash's behaviour [Bash Hackers Wiki]:

SH mode

When Bash starts in SH compatiblity mode, it tries to mimic the startup behaviour of historical versions of sh as closely as possible, while conforming to the POSIX® standard as well. The profile files read are /etc/profile and ~/.profile, if it's a login shell.

If it's not a login shell, the environment variable ENV is evaluated and the resulting filename is taken as name of the startup file.

After the startup files are read, Bash enters the POSIX(r) compatiblity mode (for running, not for starting!).

Bash starts in sh compatiblity mode when:

the base filename in argv[0] is sh (Attention dear uber-clever Linux users… /bin/sh may be linked to /bin/bash, but that doesn't mean it acts like /bin/bash)

More information can be found at the Bash Reference Manual: Bash POSIX Mode, specifically:

Process substitution is not available.

which is why your sh script is failing, as the <(..) syntax is using process substitution.

Ubuntu – Execute bash script on remote server non-interactively

Make sure that you have read security considerations

Install sshpass it's a tool for non-interactive ssh password authentication.

sudo apt install sshpass

You can use it like:

sshpass -p 'password' ssh user@server/IP

Then use it like this to run your script with its arguments:

sshpass -p 'password' ssh user@server "bash -s" < ./script.sh arg1 arg2

If it didn't work then what I suggest is to use scp and move your script to remote server, then run your command and remove the script:

sshpass -p 'password' scp script.sh user@server:/tmp/script.sh
sshpass -p 'password' ssh user@server /tmp/script.sh arg1 ar2 arg3
sshpass -p 'password' ssh user@server rm /tmp/script.sh

Security considerations [man sshpass]

First and foremost, users of sshpass should realize that ssh's insistance on only getting the password interactively is not without reason. It is close to impossible to securely store the password, and users of sshpass should consider whether ssh's public key authentication provides the same end-user experience, while involving less hassle and being more secure.

The -p option should be considered the least secure of all of sshpass's options. All system users can see the password in the command line with a simple "ps" command. Sshpass makes a minimal attempt to hide the password, but such attempts are doomed to create race conditions without actually solving the problem. Users of sshpass are encouraged to use one of the other password passing techniques, which are all more secure.

In particular, people writing programs that are meant to communicate the password programatically are encouraged to use an anonymous pipe and pass the pipe's reading end to sshpass using the -d option.