===== Docker volumes by examples =====

==== Start mysql with docker volumes ====

<code bash>
# hostpath bind mount
docker run --name mysql-db \
  -v $(pwd)/datadir:/var/lib/mysql
  -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:8.4.9

docker stop mysql.db
docker rm mysql-db

# or docker managed volume /var/lib/docker/volumes
docker volume create mysql-data
docker run --name mysql-db \
  -v mysql-data:/var/lib/mysql
  -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:8.4.9

</code>

==== NFS ====

  - https://oneuptime.com/blog/post/2026-01-30-docker-nfs-volumes/view
  - https://docs.docker.com/engine/storage/volumes/

Install NFS kernel server

<code bash>

sudo apt update
sudo apt install -y nfs-kernel-server

# Create the export directory
sudo mkdir -p /exports/shared
sudo chown nobody:nogroup /exports/shared
sudo chmod 755 /exports/shared

# add this to /etc/exports
sudo vi /etc/exports
/exports/shared    192.168.1.0/24(rw,sync,no_subtree_check,no_root_squash)


# Export the shares
sudo exportfs -ra

# Start and enable NFS server
sudo systemctl enable nfs-kernel-server
sudo systemctl start nfs-kernel-server

# Verify exports
sudo exportfs -v
</code>


Create docker volume with a NFS Share:

<code bash>
docker volume create \
  --driver local \
  --opt type=nfs \
  --opt o=addr=192.168.1.100,rw,nfsvers=4.1 \
  --opt device=:/exports/shared \
  shared-data
</code>


Use volume inside docker-compose service:

<code bash>
mkdir -p web
cd web
cat >docker-compose.yml <<EOF
services:
  app:
    image: nginx:alphine
    volumes:
      - shared-data:/usr/share/nginx/html
    deploy:
      replicas: 3

  processor:
    image: python:3.11-slim
    volumes:
      - shared-data:/data
    command: python -c "while True: pass"

volumes:
  shared-data:
    driver: local
    driver_opts:
      type: nfs
      o: addr=192.168.1.100,rw,nfsvers=4.1,soft,timeo=300
      device: ":/exports/shared"
EOF
docker compose uo -d
# access service with curlimages/curl many times
docker run --rm --network default-web curlimages/curl curl -s app
...
# check logs

# down
docker compose down
</code>


Use nfs share with docker --mount directly:

<code bash>
docker run -d \
  --name web \
  --mount type=volume,volume-driver=local,\
volume-opt=type=nfs,\
volume-opt=o=addr=192.168.1.100,\
volume-opt=device=:/exports/shared,\
dst=/usr/share/nginx/html \
  nginx:alpine
</code>