Local connection between 2 computers

Scenario: I wanna control / access my comp1 (which runs Linux) from my comp2 (which runs MacOS).

Reason: I cannot work with Data Science's stuff with comp2 (Mac M1) whereas comp1 has everything (Linux, GPU,...)

☝

Two computers must be connected to the same network!

Streaming games

In case you have a PC/Windows which playing games and you want to play these games on these machines but from another machine, let’s try Steam Link. Read this note for more: Stream games between 2 computers in the same local network.

Control visually

Windows: Windows Remote Desktop or NoMachine. WRD has a better display and usage. It looks like the same as you work on the remote machine.

Linux / MacOS: No Machine.

💡

No Machine Service is only for the “server” side. If you wish to use a “client only” side, you don’t have to enable the No Machine Service on the client, just open the No Machine app on the client, that’s it.

☝

Don’t use nx://100.xx.xxx.x:4000, use nx://192.168.xx.xx:4000 instead!

Connect via SSH

👉 I learned from this answer. We use No Machine.

❇️ On the "server computer" (comp1 -- Linux)

1# Knowing its name
2hostname
3# or `hostnamectl` or `cat /proc/sys/kernel/hostname`
4# mine: pop-os
5
6# Knowing current user
7whoami
8# mine: thi
9# You must know the password!!!
10
11# Install openssh-server
12sudo apt update
13sudo apt install openssh-server
14
15# Check comp1's ip
16ifconfig | grep "192.168"
17# mine: 192.168.1.115

Test: connect from comp1 to comp1 itself!

1ssh 127.0.0.1
2# type user1's password

❇️ On the "client computer" (comp2 -- MacOS)

1# Connect via comp1's name
2ssh thi@pop-os.local
3# Type thi's password
4
5# Connect via comp1's ip
6ssh thi@192.168.1.115

❇️ Disconnect

1exit

❇️ Copy files

1# From client to remote
2scp /from/client/file.zip thi@pop-os.local:/on/remote/
3# (change the destination name)
4scp /on/client/file.zip thi@pop-os.local:/on/remote/file_renamed.zip
5
6# From remote to client
7scp thi@pop-os.local:/on/remote/file.zip /on/client/

Tip: You can use a smtp client (eg: CyberDuck) to make things visually

1# server
2pop-os.local # or using ip address
3# port
422
5# username
6thi
7# password

Open Jupter Notebook running on comp1

👉 Docker
👉 SSH

Suppose that there is a jupyter lab server which is running on comp1 (In my case, it's running inside a docker container which is ported to comp1 via port 8888).

1# On comp2
2ssh -N -L localhost:8888:127.0.0.1:8888 thi@pop-os.local
3# Remark: keep the terminal

Then open http://localhost:8888/lab to see the result!

SSH to the docker container inside comp1

I wanna ssh to the container which is running on comp1 from comp2.

❇️ Suppose that the running container on comp1 is created from an image which hasn't set up the open-ssh by default. We will set up a server in the running container

1# Check the name of running container
2docker ps # mine: docker_ai
3
4# Go inside the running container
5docker exec -it docker_ai bash
6
7# [in the container]
8
9# Install ssh server
10apt update && apt install openssh-server && apt install nano
11# Change `root`'s password
12passwd # suppose: qwerty
13
14nano /etc/ssh/sshd_config
15# and add
16Port 2222
17PermitRootLogin yes
18
19# Restart ssh server
20/etc/init.d/ssh start

In the docker-compose.yml

1# expose the ports
2ports:
3	- "6789:2222"

1# Test on comp1
2ssh -p 6789 root@localhost
3# enter "qwerty" password for "root"
4
5# Connect from comp2
6ssh -p 6789 root@pop-os.local
7# enter "qwerty" password for "root"

❇️ In case your image has already installed openssh-server but forgot to run it by default. We will run the ssh server on port 22 for the running container.

Add below line to Dockerfile if you wanna run the openssh-server by default

1CMD $(which sshd) -Ddp 22

🚨

Remark

We shouldn't (cannot??) run 2 servers in parallel in the docker image (for example, one for jupyter notebook on port 8888 and one for openssh-server on port 22).

💡 In this case, you should keep the jupyter notebook running. Each time you wanna run the openssh-server, you can run

1docker exec docker_ai $(which sshd) -Ddp 22 # and keep this tab open
2# or
3docker exec -d .... # detach mode

You can also do this completely from comp2

1ssh thi@pop-os.local
2# Then you are in comp1's terminal
3docker exec ....

Important remark: If you enter the container's shell and then you wanna exit with exit or logout command. It also terminates the server and you have to run the server again!

☝

Don't forget to forward the port 22 (in container) to 6789 in comp1 via docker-compose.yml.

1# On comp1
2docker exec <container_name> $(which sshd) -Ddp 22
3# Keep this tab open and running

1# On comp2
2ssh -p 6789 root@pop-os.local
3# enter pwd: "qwerty" as in the Dockerfile