having problem when using k3sup join command

Question

I have generated ssh-key on client and copied them to master and worker nodes. The path is ~/.ssh/id_rsa. I have this error and using sudo -S doesn't fix it too.

k3sup join --ip $WORKER_IP --user $WORKER_USER --server-ip $MASTER_IP --server-user $MASTER_USER --k3s-extra-args "--node-external-ip $WORKER_IP --node-ip $WORKER_IP" --k3s-channel stable --print-command


Running: k3sup join
ssh: sudo cat /var/lib/rancher/k3s/server/node-token
sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper
sudo: a password is required
Error: unable to get join-token from server: Process exited with status 1

However, I expect getting the following output:

$ k3sup join --ip $WORKER_IP --user $WORKER_USER --server-ip $MASTER_IP --server-user $MASTER_USER --k3s-extra-args "--node-external-ip $WORKER_IP --node-ip $WORKER_IP" --k3s-channel stable --print-command
Running: k3sup join
ssh: sudo cat /var/lib/rancher/k3s/server/node-token

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::server:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
ssh: curl -sfL https://get.k3s.io | K3S_URL='https://10.1.1.1:6443' K3S_TOKEN='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::server:xxxxxxxxxxxxxxxxxxxxxxxxx' INSTALL_K3S_CHANNEL='stable' sh -s - --node-external-ip 10.1.1.2 --node-ip 10.1.1.2
\[INFO\]  Finding release for channel stable
\[INFO\]  Using v1.20.0+k3s2 as release
\[INFO\]  Downloading hash https://github.com/rancher/k3s/releases/download/v1.20.0+k3s2/sha256sum-amd64.txt
\[INFO\]  Downloading binary https://github.com/rancher/k3s/releases/download/v1.20.0+k3s2/k3s
\[INFO\]  Verifying binary download
\[INFO\]  Installing k3s to /usr/local/bin/k3s
\[INFO\]  Creating /usr/local/bin/kubectl symlink to k3s
\[INFO\]  Creating /usr/local/bin/crictl symlink to k3s
\[INFO\]  Creating /usr/local/bin/ctr symlink to k3s
\[INFO\]  Creating killall script /usr/local/bin/k3s-killall.sh
\[INFO\]  Creating uninstall script /usr/local/bin/k3s-agent-uninstall.sh
\[INFO\]  env: Creating environment file /etc/systemd/system/k3s-agent.service.env
\[INFO\]  systemd: Creating service file /etc/systemd/system/k3s-agent.service
\[INFO\]  systemd: Enabling k3s-agent unit
Created symlink /etc/systemd/system/multi-user.target.wants/k3s-agent.service → /etc/systemd/system/k3s-agent.service.
\[INFO\]  systemd: Starting k3s-agent
Logs: Created symlink /etc/systemd/system/multi-user.target.wants/k3s-agent.service → /etc/systemd/system/k3s-agent.service.
Output: \[INFO\]  Finding release for channel stable
\[INFO\]  Using v1.20.0+k3s2 as release
\[INFO\]  Downloading hash https://github.com/rancher/k3s/releases/download/v1.20.0+k3s2/sha256sum-amd64.txt
\[INFO\]  Downloading binary https://github.com/rancher/k3s/releases/download/v1.20.0+k3s2/k3s
\[INFO\]  Verifying binary download
\[INFO\]  Installing k3s to /usr/local/bin/k3s
\[INFO\]  Creating /usr/local/bin/kubectl symlink to k3s
\[INFO\]  Creating /usr/local/bin/crictl symlink to k3s
\[INFO\]  Creating /usr/local/bin/ctr symlink to k3s
\[INFO\]  Creating killall script /usr/local/bin/k3s-killall.sh
\[INFO\]  Creating uninstall script /usr/local/bin/k3s-agent-uninstall.sh
\[INFO\]  env: Creating environment file /etc/systemd/system/k3s-agent.service.env
\[INFO\]  systemd: Creating service file /etc/systemd/system/k3s-agent.service
\[INFO\]  systemd: Enabling k3s-agent unit
\[INFO\]  systemd: Starting k3s-agent

Answer 1

you are missing config on your worker node that allows to run sudo without having to repeat password. Do sudo visudo on worker node then add following worker-username ALL=(ALL) NOPASSWD: ALL save and exit more info available here: https://github.com/alexellis/k3sup#pre-requisites-for-k3sup-servers-and-agents