Got permission denied while trying to connect to the Docker daemon socket at uni code example

Example 1: Got permission denied while trying to connect to the Docker daemon socket

sudo chmod 666 /var/run/docker.sock

Example 2: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.40/containers/json: dial unix /var/run/docker.sock: connect: permission denied

sudo usermod -aG docker ${USER}

Example 3: 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/auth: dial unix /var/run/docker.sock: connect: permission denied

docker permission for linux ec2