docker_overlay2.sh

#!/bin/bash
true
SCRIPT_NAME="Change to Docker overlay2"
# shellcheck source=lib.sh
source /var/scripts/fetch_lib.sh

# T&M Hansson IT AB © - 2024, https://www.hanssonit.se/

# Check for errors + debug code and abort if something isn't right
# 1 = ON
# 0 = OFF
DEBUG=0
debug_mode

# Must be root
root_check

### Migrating Docker images to overlay2 ###
# https://www.techandme.se/changes-to-docker-ce-in-the-nextcloud-vm/
# Credits to: https://gist.github.com/hydra1983/22b2bed38b4f5f56caa87c830c96378d

# Make sure DOCKERBACKUP is created
if [ -f "$NCPATH"/config/config.php ]
then
    NCDATA="$(grep 'datadir' "$NCPATH"/config/config.php | awk '{print $3}' | cut -d "'" -f2)"
fi
DOCKERBACKUP="$NCDATA/DOCKERBACKUP"
mkdir -p "$DOCKERBACKUP"

# Check if aufs and don't run
if grep -q "aufs" /etc/default/docker
then
  msg_box "This script doesn't support images that uses the AUFS driver, sorry

You are welcome to send a PR, or report an issue here: $ISSUES"
    exit 1
fi

readonly DB_FILE="$DOCKERBACKUP/images.db"
readonly IMG_DIR="$DOCKERBACKUP/images"

save_images() {
  print_text_in_color "$ICyan" "Create ${IMG_DIR}"
  if [[ ! -d "${IMG_DIR}" ]]; then
    mkdir "${IMG_DIR}"
  fi
  
  print_text_in_color "$ICyan" "Create ${DB_FILE}"
  docker images|grep -v 'IMAGE ID'|awk '{printf("%s %s %s\n", $1, $2, $3)}'|column -t > "${DB_FILE}"
  
  print_text_in_color "$ICyan" "Read ${DB_FILE}"
  local images
  while read -r image; do
     images+=("$image"); 
  done <<< "$(cat "${DB_FILE}")"
  
  local name tag id
  for image in "${images[@]}"; do
    name=$(echo "$image"|awk '{print $1}')
    tag=$(echo "$image"|awk '{print $2}')
    id=$(echo "$image"|awk '{print $3}')
        
    if [[ "${id}" != "" ]]; then
      local imgPath="${IMG_DIR}/${id}.dim"

      if [[ ! -f "${imgPath}" ]] ; then
        print_text_in_color "$ICyan" "[DEBUG] save ${id} ${name}:${tag} to ${imgPath}"
        (time  docker save -o "${imgPath}" "${name}":"${tag}") 2>&1 | grep real
      else
        print_text_in_color "$ICyan" "[DEBUG] ${id} ${name}:${tag} already saved"
      fi
    fi    
  done
}

load_images() {
  if [[ ! -f "${DB_FILE}" ]]; then
    print_text_in_color "$ICyan" "No ${DB_FILE} to read"
    exit 0
  fi

  if [[ ! -d "${IMG_DIR}" ]]; then
    print_text_in_color "$ICyan" "No ${IMG_DIR} to load images"
    exit 0
  fi

  print_text_in_color "$ICyan" "Read ${DB_FILE}"
  local images
  while read -r image; do
     images+=("$image"); 
  done <<< "$(cat "${DB_FILE}")"

  local name tag id
  for image in "${images[@]}"; do
    name=$(echo "$image"|awk '{print $1}')
    tag=$(echo "$image"|awk '{print $2}')
    id=$(echo "$image"|awk '{print $3}')
        
    if [[ "${id}" != "" ]]; then
      local imgPath="${IMG_DIR}/${id}.dim"

      if [[ "$(docker images|grep "${id}" | grep "${name}" | grep "${tag}")" == "" ]]; then        
        if [[ "$(docker images|grep "${id}")" == "" ]]; then
          print_text_in_color "$ICyan" "[DEBUG] load ${id} ${name}:${tag} from ${imgPath}"
          docker load -i "${imgPath}"
        else
          print_text_in_color "$ICyan" "[DEBUG] tag ${id} as ${name}:${tag}"
          docker tag "${id}" "${name}":"${tag}"
        fi
      else
        print_text_in_color "$ICyan" "[DEBUG] ${id} ${name}:${tag} already loaded"
      fi
    fi
  done
}

# Save all docker images in one file
check_command docker ps -a > "$DOCKERBACKUP"/dockerps.txt
check_command docker images | sed '1d' | awk '{print $1 " " $2 " " $3}' > "$DOCKERBACKUP"/mydockersimages.list
msg_box "The following images will be saved to $DOCKERBACKUP/images

$(cat "$DOCKERBACKUP"/mydockersimages.list)

It may take a while so please be patient."

check_command save_images

# Set overlay2
if ! [ -f /etc/docker/daemon.json ] || ! grep -q '"storage-driver": "overlay2"' /etc/docker/daemon.json
then
    cat << OVERLAY2 > /etc/docker/daemon.json
{
  "storage-driver": "overlay2"
}
OVERLAY2
fi

rm -f /etc/systemd/system/docker.service
systemctl restart docker.service
print_text_in_color "$ICyan" "Reloading daemon"
systemctl daemon-reload
print_text_in_color "$ICyan" "Restarting the docker service"
check_command systemctl restart docker.service
apt-mark unhold docker-ce

# Remove old cached versions to avoid failures on update to new version
rm -Rf /var/cache/apt/archives/docker*
rm -Rf /var/cache/apt/archives/container*
rm -Rf /var/cache/apt/archives/aufs*

# Upgrade docker to latest version
rm -Rf /var/lib/docker
apt-get update -q4 & spinner_loading
apt-get upgrade docker-ce -y

# Load docker images back
print_text_in_color "$ICyan" "Importing saved docker images to overlay2..."
check_command load_images
msg_box "Your Docker images are now imported to overlay2, but not yet running.

To start the images again, please run the appropriate 'docker run' command for each docker.
These are all the imported docker images:
$(cat "${DB_FILE}")

You can also find the file with the imported docker images here:
$DB_FILE

If you experience any issues, please report them to $ISSUES."
rm -f "$DOCKERBACKUP"/mydockersimages.list