Cannot run docker after install by snap command inside Ubuntu 22.04 EC2

In the past, I can run docker easily by command sudo apt-get install docker... . Today, I tried experience new way, install by snap command, then

Microsoft Windows [Version 10.0.19044.2486]
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C:\Users\Administrator\Downloads>ssh -i "vy.pem" [email protected]
Welcome to Ubuntu 22.04.1 LTS (GNU/Linux 5.15.0-1028-aws x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Mon Jan 30 02:00:14 UTC 2023

  System load:  0.16845703125     Processes:                111
  Usage of /:   21.7% of 7.57GB   Users logged in:          0
  Memory usage: 3%                IPv4 address for docker0: 172.17.0.1
  Swap usage:   0%                IPv4 address for eth0:    172.31.32.168


0 updates can be applied immediately.


The list of available updates is more than a week old.
To check for new updates run: sudo apt update

Last login: Mon Jan 30 02:00:15 2023 from 14.248.82.245
Welcome to Ubuntu 22.04.1 LTS (GNU/Linux 5.15.0-1028-aws x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Mon Jan 30 02:00:14 UTC 2023

  System load:  0.16845703125     Processes:                111
  Usage of /:   21.7% of 7.57GB   Users logged in:          0
  Memory usage: 3%                IPv4 address for docker0: 172.17.0.1
  Swap usage:   0%                IPv4 address for eth0:    172.31.32.168


0 updates can be applied immediately.


The list of available updates is more than a week old.
To check for new updates run: sudo apt update

Last login: Mon Jan 30 02:00:15 2023 from 14.248.82.245
ubuntu@ip-172-31-32-168:~$ docker ps -a
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json?all=1": dial unix /var/run/docker.sock: connect: permission denied
ubuntu@ip-172-31-32-168:~$ sudo usermod -aG docker $USER
ubuntu@ip-172-31-32-168:~$ newgrp docker
ubuntu@ip-172-31-32-168:~$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/create": dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.
ubuntu@ip-172-31-32-168:~$ sudo chown "$USER":"$USER" /home/"$USER"/.docker -R
chmod g+rwx "$HOME/.docker" -Rsudo chmod g+rwx "$HOME/.docker" -Rchown: cannot access '/home/ubuntu/.docker': No such file or directory
ubuntu@ip-172-31-32-168:~$ sudo groupadd docker
groupadd: group 'docker' already exists
ubuntu@ip-172-31-32-168:~$ sudo usermod -aG docker ${USER}
ubuntu@ip-172-31-32-168:~$ su -s ${USER}
Password:
^C
ubuntu@ip-172-31-32-168:~$ exit
exit
ubuntu@ip-172-31-32-168:~$ exit
logout
Connection to ec2-18-142-158-158.ap-southeast-1.compute.amazonaws.com closed.

C:\Users\Administrator\Downloads>ssh -i "vy.pem" [email protected]
Welcome to Ubuntu 22.04.1 LTS (GNU/Linux 5.15.0-1028-aws x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  System information as of Mon Jan 30 02:03:18 UTC 2023

  System load:  0.01220703125     Processes:                113
  Usage of /:   21.7% of 7.57GB   Users logged in:          0
  Memory usage: 3%                IPv4 address for docker0: 172.17.0.1
  Swap usage:   0%                IPv4 address for eth0:    172.31.32.168


0 updates can be applied immediately.


The list of available updates is more than a week old.
To check for new updates run: sudo apt update

Last login: Mon Jan 30 02:00:57 2023 from 14.248.82.245
ubuntu@ip-172-31-32-168:~$ docker ps -a
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json?all=1": dial unix /var/run/docker.sock: connect: permission denied
ubuntu@ip-172-31-32-168:~$ usermod -aG docker ${USER}
usermod: Permission denied.
usermod: cannot lock /etc/passwd; try again later.
ubuntu@ip-172-31-32-168:~$ docker ps -a
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json?all=1": dial unix /var/run/docker.sock: connect: permission denied
ubuntu@ip-172-31-32-168:~$ sudo service docker restart
Failed to restart docker.service: Unit docker.service not found.
ubuntu@ip-172-31-32-168:~$
ubuntu@ip-172-31-32-168:~$
ubuntu@ip-172-31-32-168:~$
ubuntu@ip-172-31-32-168:~$
ubuntu@ip-172-31-32-168:~$
ubuntu@ip-172-31-32-168:~$ docker ps -a
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json?all=1": dial unix /var/run/docker.sock: connect: permission denied
ubuntu@ip-172-31-32-168:~$ su root
Password:
root@ip-172-31-32-168:/home/ubuntu#
root@ip-172-31-32-168:/home/ubuntu#
root@ip-172-31-32-168:/home/ubuntu#
root@ip-172-31-32-168:/home/ubuntu# docker build . -t kong-your-tag
error checking context: 'no permission to read from '/home/ubuntu/.bash_history''.
root@ip-172-31-32-168:/home/ubuntu#

How to use docker as normal?

The snapcraft store page for docker explains what to do. https://snapcraft.io/docker

A snippet:

"By default, Docker is only accessible with root privileges (sudo). If you want to use docker as a regular user, you need to add your user to the docker group."

 sudo addgroup --system docker
 sudo adduser $USER docker
 newgrp docker
 sudo snap disable docker
 sudo snap enable docker