https://docs.docker.com/storage/volumes/

apt-get -y install curl unzip dialog
curl -fSSL get.docker.com | sh

Useful alias to exclude container overlays from the df command for use in .bashrc or .profile:

alias df='/usr/bin/df -x overlay'

docker logs --follow <containername>

To build the docker image based on a Dockerfile in the current directory, use:

docker build .

Update docker container to latest version via docker compose:

#Single container:
docker compose pull calibre-web
docker compose up -d calibre-web
docker image prune

#Update all containers:
docker compose pull
docker compose up -d
docker image prune

Docker compose health checks:
https://medium.com/geekculture/how-to-successfully-implement-a-healthcheck-in-docker-compose-efced60bc08e

https://stefanjarina.gitbooks.io/docker/content/swarm-mode/healthchecks.html

Copying files from/to containers

docker cp dockerimage:/bla ./bla
docker cp ./bla dockerimage:/bla

Flatten docker image layers:

FROM yourbuildimage as build
# your existing build steps here
FROM scratch
COPY --from=build / /
CMD ["/your/start/script"]

Change mount points of existing docker containers;

e.g. mount /home/<user-name> folder of host to the /mnt folder of the existing (not running) container.

1. stop docker container or whole docker engine

   systemctl stop docker.service

2. Open configuration file corresponding to the stopped container, which can be found at /var/lib/docker/containers/99d…1fb/config.v2.json (may be config.json for older versions of docker). For pretty print use

   vi <(jq . /var/lib/docker/containers/<container-ID>/config.v2.json)
   Save updates to a file: :w config.v2.json
   Exit vim: :q!
   Update existing file: jq -c . config.v2.json > /var/lib/docker/containers/<container-ID>/config.v2.json
    

3. Find MountPoints section: “MountPoints”:{}.
4. Replace the contents with something like this (you can copy proper contents from another container with proper settings):

   "MountPoints":{"/mnt":{"Source":"/home/<user-name>","Destination":"/mnt","RW":true,"Name":"","Driver":"","Type":"bind","Propagation":"rprivate","Spec":{"Type":"bind","Source":"/home/<user-name>","Target":"/mnt"},"SkipMountpointCreation":false}}

   or the same (formatted):

     "MountPoints": {
       "/mnt": {
         "Source": "/home/<user-name>",
         "Destination": "/mnt",
         "RW": true,
         "Name": "",
         "Driver": "",
         "Type": "bind",
         "Propagation": "rprivate",
         "Spec": {
           "Type": "bind",
           "Source": "/home/<user-name>",
           "Target": "/mnt"
         },
         "SkipMountpointCreation": false
       }
     }

5. Start or restart the docker service:

   systemctl start docker.service
   service docker restart

6. Start the container if necessary:

   docker start <container-name/ID>

Containerised PHP & NGINX on Alpine, image size ~60MB:
https://levelup.gitconnected.com/containerizing-nginx-php-fpm-on-alpine-linux-953430ea6dbc
https://github.com/johnathanesanders/docker-nginx-fpm

Log nginx to stdout in Dockerfile:

# forward request and error logs to docker log collector
RUN ln -sf /dev/stdout /var/log/nginx/access.log \
	&& ln -sf /dev/stderr /var/log/nginx/error.log

docker tag current/image:tag new/image:tag

docker exec -it <mycontainer> bash
docker exec -it <mycontainer> /bin/sh

Make sure the relevant GPU drivers are installed on the base system, then pass through the device via docker compose.
Check devices are available, there should be a device per GPU starting at renderD128 for the first GPU:

ls -la /dev/dri

  devices:
   - /dev/dri:/dev/dri

for AMD:
https://rocm.docs.amd.com/projects/install-on-linux/en/latest/install/install-methods/package-manager/package-manager-debian.html
https://rocm.docs.amd.com/projects/install-on-linux/en/latest/how-to/docker.html

mkdir --parents --mode=0755 /etc/apt/keyrings
wget https://repo.radeon.com/rocm/rocm.gpg.key -O - | gpg --dearmor | sudo tee /etc/apt/keyrings/rocm.gpg > /dev/null
echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/rocm.gpg] https://repo.radeon.com/rocm/apt/6.4.3 jammy main" > tee /etc/apt/sources.list.d/rocm.list
echo -e 'Package: *\nPin: release o=repo.radeon.com\nPin-Priority: 600' > /etc/apt/preferences.d/rocm-pin-600
apt update
apt install rocm

Then add to the docker containers:

  devices:
    - /dev/kfd
    - /dev/dri
  security_opt:
    - seccomp=unconfined
  environment:
    - LIBVA_DRIVER_NAME=radeonsi

Alpine Linux docker images may require libva to be installed:

    post_start:
      # for 13th gen Iris Xe GPUs use intel-media-driver for older gens libva-intel-driver
      # - command: apk add libva-intel-driver intel-media-driver
      #   user: root
      # For AMD
      - command: apk add libva libva-utils mesa-va-gallium
        user: root

nvtop can be used for AMD and NVidia gpus to see if the gpu is being used.
On Debian, nvtop is in the contrib repositories which need to be added.

#bookworm
sed -r 's/^deb(.*)$/deb\1 contrib/g' /etc/apt/sources.list

#new deb822 sources format
sed -i 's/^Components: main$/& contrib non-free non-free-firmware/' /etc/apt/sources.list.d/debian.sources

apt update

On Ubuntu systems, nvtop is in the default repositories.

apt-get install nvtop

Short form of docker ps to only get the container names:

docker ps | sed 's/   */#/g' | cut -d "#" -f 7

https://stackoverflow.com/questions/50667371/docker-ps-output-formatting-list-only-names-of-running-containers

Error response from daemon: all predefined address pools have been fully subnetted

/etc/docker/daemon.json

{
"default-address-pools":[
    {"base":"169.254.2.0/23","size":28},
    {"base":"169.254.4.0/22","size":28},
    {"base":"169.254.8.0/21","size":28},
    {"base":"169.254.16.0/20","size":28},
    {"base":"169.254.32.0/19","size":28},
    {"base":"169.254.64.0/18","size":28},
    {"base":"169.254.128.0/18","size":28},
    {"base":"169.254.192.0/19","size":28},
    {"base":"169.254.224.0/20","size":28},
    {"base":"169.254.240.0/21","size":28},
    {"base":"169.254.248.0/22","size":28}
  ]
}

docker restart
docker network prune