Windows 7: bash: sudo: command not found

[chefhoobajoob]

I'm trying to run mongo containers on my Windows 7, and ran into an issue whose proposed resolution requires running these commands on the host system:

$ echo never | sudo tee /sys/kernel/mm/transparent_hugepage/enabled
$ echo never | sudo tee /sys/kernel/mm/transparent_hugepage/defrag

But doing so from the toolbox quickstart terminal gives me these results:

$ echo never | sudo tee /sys/kernel/mm/transparent_hugepage/enabled
bash: sudo: command not found

Indeed, sudo is nowhere to be found on the virtualbox machine.

How can I achieve the resolution recommended in this issue on Windows 7?

[narita1980]

Do you use Docker Toolbox ?
if so, please run the following

$ docker-machine ssh default
docker@default:~$ echo never | sudo tee /sys/kernel/mm/transparent_hugepage/enabled
never
docker@default:~$ echo never | sudo tee /sys/kernel/mm/transparent_hugepage/defrag
never

[chefhoobajoob]

I assume those are to be run from the Windows command shell, and not from the quickstart terminal?

So, I was able to run these commands, but then I recycled power on the vbox machine and started up the mongo container, and I'm still getting the warnings about transparent_hugepage enabled and defrag, so it appears not to have had any effect:

docker@default:~$ cat /sys/kernel/mm/transparent_hugepage/enabled
[always] madvise never
docker@default:~$

As an aside, when I use docker-machine ssh default, the interactive shell echos back strange character combinations when I enter either the Backspace or Delete keys, and it displays a bunch of strange characters around ls entries, like so:

docker@default:~$ ls /sys/kernel
←[1;34mboot_params←[0m/        ←[0;0mkexec_crash_loaded←[0m  ←[0;0mnotes←[0m               ←[1;34mtracing←[0m/
←[1;34mdebug←[0m/              ←[0;0mkexec_crash_size←[0m    ←[0;0mprofiling←[0m           ←[0;0muevent_helper←[0m
←[0;0mfscaps←[0m              ←[0;0mkexec_loaded←[0m        ←[0;0mrcu_expedited←[0m       ←[0;0muevent_seqnum←[0m
←[1;34miommu_groups←[0m/       ←[1;34mmm←[0m/                 ←[1;34msecurity←[0m/           ←[0;0mvmcoreinfo←[0m
docker@default:~$

I assume this is harmless, but I'd like to get rid of those characters.

[chefhoobajoob]

ok - if I don't reboot, stop the container, run these commands, then restart the container, the complaints go away.

How can I make these settings permanent?

[anandumdas]

The error happens because the binary you are trying to call from command line is only part of the current user's PATH variable, but not a part of root user's PATH.

You can verify this by locating the path of the binary you are trying to access. In my case I was trying to call "bettercap-ng". So I ran,

$ which bettercap-ng

output: /home/user/work/bin/bettercap

I checked whether this location is part of my root user's PATH.

$ sudo env | grep ^PATH

output: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin

So sudo cannot find the binary that I am trying to call from commandline. Hence returns the error command not found.

You can direct sudo to use the current user's PATH when calling a binary like below.

$ sudo -E env "PATH=$PATH" [command] [arguments]

In fact, one can make an alias out of it:

$ alias mysudo='sudo -E env "PATH=$PATH"'

It's also possible to name the alias itself sudo, replacing the original sudo.

Please refer to this video for step by step solution