Set up Docker's apt repository.

---------------------------------------------------------------------
# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

---------------------------------------------------------------------



To install the latest version, run:

---------------------------------------------------------------------
 sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
---------------------------------------------------------------------
Make sure it exists and is writable:
---------------------------------------------------------------------
sudo mkdir -p /media/harish/E-drive/Ubnutu-sw-repo/docker-data
sudo chown root:root /media/harish/E-drive/Ubnutu-sw-repo/docker-data
---------------------------------------------------------------------

✅ 3. Set Custom Docker Data Root
Create or edit the Docker daemon config:

---------------------------------------------------------------------
sudo mkdir -p /etc/docker
sudo nano /etc/docker/daemon.json
---------------------------------------------------------------------

Add this content:
---------------------------------------------------------------------
{
  "data-root": "/media/harish/E-drive/Ubnutu-sw-repo/docker-data"
}

---------------------------------------------------------------------
Then save the file.

✅ 4. Restart Docker
---------------------------------------------------------------------
sudo systemctl daemon-reexec
sudo systemctl daemon-reload
sudo systemctl enable docker
sudo systemctl start docker
sudo systemctl restart docker
---------------------------------------------------------------------

sudo docker info | grep "Docker Root Dir"

---------------------------------------------------------------------
✅ Solution: Add User to docker Group
Run this:
---------------------------------------------------------------------
sudo usermod -aG docker gharish
---------------------------------------------------------------------


Then log out and log back in (very important — group membership updates only take effect after re-login).

After that, try:
---------------------------------------------------------------------
docker ps
---------------------------------------------------------------------

You should no longer get the permission denied error.