Remote usage install guide

In the remote usage model:

  • wult is installed on the controller
  • drivers are deployed to the SUT
  • wult measures the SUT and stores the results on the controller

In general, following the local usage install guide and install wult to the controller. This page provides the delta (what should be done differently or additional aspects).

1 Update

Update the packages using the same method as described for local installation but run the wult deploy command with -H SUTNAME to deploy wult to the SUT and not locally, i.e:

wult deploy -H SUTNAME

2 OS packages

Everything is the same as in the local usage mode, but some of the dependencies should be installed on the SUT instead of the controller.

Fedora

SUT:

sudo dnf install -y make gcc elfutils-libelf-devel rsync libbpf-devel
sudo dnf install -y libffi-devel redhat-rpm-config openssl-devel
sudo dnf install -y kernel-devel

Controller:

sudo dnf install -y git python3 python3-devel python3-pip python3-numpy
sudo dnf install -y python3-colorama python3-yaml python3-pandas
sudo dnf install -y python3-paramiko rsync

Ubuntu

SUT:

sudo apt install -y make gcc libelf-dev libssl-dev libbpf-dev
sudo apt install -y linux-headers-$(uname -r)

Controller:

sudo apt install -y git python3-pip python3-numpy python3-plotly
sudo apt install -y python3-colorama python3-yaml python3-pandas
sudo apt install -y python3-paramiko rsync

3 Install wult, stats-collect and pepc

Install them on the controller using the same method described for local installation.

4 Deploy wult drivers

Make sure that passwordless SUT access works, then run the following command on the controller:

wult deploy -H SUTNAME

Important note

The drivers are installed only for the currently running kernel. If you reboot the SUT to a different kernel, you have to re-run wult deploy -H SUTNAME on the controller.

4.1 Passwordless SUT login

In case of the remote usage model, you need to configure passwordless root SSH login from the controller to the SUT. You are going to run wult as a regular user on the controller, but it will SSH into the SUT as root. Please, use online documentation to find out how to do this for your Linux distribution, but here is one way of doing this (worked on Fedora and Ubuntu).

Configure the SSH server on the SUT to allow for root login by enabling the "PermitRootLogin" option. Then restart the SSH server.

sudo sh -c 'echo "PermitRootLogin yes" >> /etc/ssh/sshd_config'
sudo systemctl restart sshd

You'll need user SSH keys on the controller. If you do not have them, generate a new SSH key pair on the controller. For example, this command (executed as under your user on the controller) will generate a pair of RSA keys - "sut" (private key) and "sut.pub" (public key):

cd ~/.ssh
ssh-keygen -t rsa -f sut

And the last step is to configure the controller to use the "~/.ssh/sut" private key when authenticating to the SUT. You can run something like this on the controller:

cat <<EOF >> ~/.ssh/config
Host SUTNAME
    IdentityFile ~/.ssh/sut
EOF

Now you should be able to log in to the SUT as root without typing the password. Test it by running the following on the controller:

ssh root@SUTNAME

If you still have issues, enable sshd debug level logs on the SUT, and check them out, they usually give very good clues. Use ssh -v on the controller to get verbose messages, which also can give some clues.