===== Remote Management using SSH =====

If you prefer (or have to use) a command line for managing Blocks, here's a video showing you how to do this. SSH is a terminal command available on all major operating systems, allowing you to log in to a remote computer, execute commands, copy files back and forth, etc, all using a secure and encrypted connection.
{{vimeo>578111268?full}}

==== List of Commands ====

Here's an overview of commands demonstrated in this video.

<code>
# In Blocks server's terminal window, to see its IP address
ip a

# Use the "sudo" prefix under the pixi-admin user to run system level command XXX
sudo XXX

# E.g., Blocks server's terminal window, after logging in as pixi-admin
sudo systemct enable --now ssh
# Alternatively, use webmin to enable ssh

# Now you can log in from remote computer over network
ssh pixi-server@<IP-of-Blocks-server>

# First time, need to accept the Fingerprint" of the Blocks server
# You can use domain name in place of IP-of-Blocks-server if you 
# have a DNS pointing to your Blocks server.
# Enter the pixi-server user's password when requested

# IMPORTANT: If you open up a port for SSH from the Internet.
# Do NOT use password-based ssh login. Use key authentication instead.
# Then also DISABLE password authentication. Google for:
#	ssh key authentication disable password

# Stopping and starting Blocks from within /home/pixi-server
./stop.sh
./start.sh

# stop.sh and start.sh are shell script files (similar to Windows BAT files).
# See what's inside
cat start.sh

# The shell scripts use the systemctl command to manipulate a user service (here Blocks).
# For example, to check on Block's status
systemctl --user status blocks
# Note that "systemctl --user xxx" works only when logged in as the pixi-server user 
# (not under pixi-admin)

# The leading period represents the "current working directory", 
# and must be specified to run the shell scripts in the current directory.

# To see the current working directory, use
cwd

# To change directory to one inside the current directory
cd name-of-subdirectory

# To move one level up
cd ..

# To see what's inside the current directory
ls

# To see details on what's in the current directory (including hidden files)
ls -al


# Navigate to log directory:
cd ~/PIXILAB-Blocks-root/logs

# View the entire log file:
cat latest.log

# View the last couple of lines in the current log file:
tail latest.log

# Follow what's added to the log file in real time
tail -f latest.log
# To stop following, press Ctrl-C

# Open a second terminal to start/stop blocks while 
# following the log file in the other terminal window.

# Edit the config file

nano PIXILAB-Blocks-config.yml
# Or perhaps just config.yml if inside the Blocks root

# View general performance and running processes
htop

# display free disk space
df

# Move files
mv

# Copy files
cp

# Remove files and directories
rm
rm -r

# Using a new terminal window on your local machine (not logged in over ssh)

# Copy files TO your Blocks server
scp XXXX pixi-server@<IP-of-Blocks-server>:/home/pixi-server

# Copy file FROM your blocks server
scp pixi-server@<IP-of-Blocks-server>:/home/pixi-server/PIXILAB-Blocks-root/logs/latest.log .
# Notice the period at the end of the command, representing the current directory on your local computer

# Terminate the ssh session
exit

# Logging in as the admin user (from the remote terminal)
ssh pixi-admin@<IP-of-Blocks-server>

# Update OS and system software
sudo apt update
sudo apt upgrade

# Commands requiring the use of sudo don't work under pixi-server

# Enable/Disable Start/Stop system services
sudo systemctl enable webmin
sudo systemctl enable smbd
sudo systemctl start webmin
# Describe the difference between enable/disable and start/stop
sudo systemctl status webmin
sudo systemctl stop webmin

# Rebooting the remote computer
sudo reboot now
</code>


==== Warnings ====
If you log on to a computer that you e.g reimage you may see a warning like this. It may look a bit scary but the underlying reason is in that case that you already used ssh wo this ip or domain name and is is associated with differens ssh id keys. The intention of such warning is to make the user to consider if it is legit or not. 
{{:blocks:ssh:screenshot_2025-11-14_115333.png?600|}}

Rather that editing the file the following commands can be used in the terminal to clear the associated keys and get ready for new ones:
<code>
ssh-keygen -R <ip or domain> 
</code>
Example:
<code>
ssh-keygen -R 10.0.1.195
</code>