docker-maintenance/docker-maintenance

#!/bin/bash

# -- Docker Maintenance Script
# -- Written by: Robert Partridge (https://fosstodon.org/@techaddressed)
# -- Project URL: https://gitea.techaddressed.com/robert/docker-maintenance/
# -- License: MIT License (https://choosealicense.com/licenses/mit/)


# determine the script's directory
scriptDirectory="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

# import script functions
source $scriptDirectory/docker-maintenance-functions

# import user modifiable variables from .env file
source $scriptDirectory/docker-maintenance.env

# check whether to bypass root permission requirement
if [ "$bypassRoot" = false ]
then

  # check for root privileges
  if [ "$EUID" -ne 0 ]
  then 

    # write error to standard output & exit
    echo "Error: please run this script with sudo / root privileges"
    exit

  fi

fi

# get the current date
currentDate=$(date +'%F')
currentYear=$(date +'%Y')
currentMonth=$(date +'%m')

# create backup directory if necessary
mkdir -p $backupLocation

# get log filenames
maintenanceLog="$logLocation/$currentYear/$currentMonth-maintenance.log"
errorLog="$logLocation/$currentYear/$currentMonth-errors.log"

# setup log folders/files if necessary
mkdir -p $logLocation/$currentYear
touch $maintenanceLog
touch $errorLog

# determine space required to perform container backup
backup_size

# get available space at backup location
availableArray=(`df $backupLocation | grep "% /"`)
availableSpace=${availableArray[3]}

# check for sufficient space at backup location
if [ $requiredSpace -gt $availableSpace ]
then

  # write error to standard output & error log then exit
  echo "Error: insufficient space available for backup files"
  write_log "$errorLog" "Error: insufficient space available for backup files - $requiredSpace kilobytes required / $availableSpace kilobytes available"
  exit

fi


echo
echo "-- BEGINNING DOCKER MAINTENANCE --"
echo

write_log "$maintenanceLog" "Beginning Maintenance - Backup Method: $backupMethod"

if [ "$backupMethod" = "files" ]
then

  # loop through container subdirectories
  for c in ${containerDirs[@]}; do

    # create backup folder if needed
    mkdir -p $backupLocation/$c

    # navigate to container's folder
    cd $containerLocation/$c

    # get size of the container
    sizeArray=(`du -s`)
    containerSize=${sizeArray[0]}

    # record stopping the container
    write_log "$maintenanceLog" "stopping $c"

    # stop the container
    docker-compose down

    # record backup .tar.gz file creation to log
    currentTime=$(date +'%T')
    write_log "$maintenanceLog" "compressing $c-backup-$currentDate-$currentTime.tar.gz"

    # create tar archive
    echo "Creating $c archive"
    tar -czvf $backupLocation/$c/$c-backup-$currentDate-$currentTime.tar.gz ./ >> /dev/null

    # get archive size
    sizeArray=(`du -s $backupLocation/$c/$c-backup-$currentDate-$currentTime.tar.gz`)
    tarSize=${sizeArray[0]}

    # record compression to log
    write_log "$maintenanceLog" "$containerSize KB compressed to $tarSize KB"

    # record image pull to log
    write_log "$maintenanceLog" "pulling updated container image"

    # pull updated container image
    docker-compose pull

    # record container start to log
    write_log "$maintenanceLog" "starting / updating $c"

    # start / update container
    docker-compose up -d

    # backup retention check
    backup_check $c $keepBackups $numBackups ${backupArray[0]} $backupLocation $maintenanceLog

  done

fi

if [ "$backupMethod" = "snapshot" ]
then

  dirCount=0

  # loop through container names
  for c in ${containerNames[@]}; do

    # create backup folder if needed
    mkdir -p $backupLocation/$c

    # record backup image creation
    write_log "$maintenanceLog" "creating $c-backup image"

    # commit backup image
    echo "Committing $c backup image"
    docker commit -p $c $c-backup >> /dev/null

    # get size of the backup image
    container_size

    # record backup .tar file creation to log
    currentTime=$(date +'%T')
    write_log "$maintenanceLog" "backing up $c to $backupLocation/$c/$c-backup-$currentDate-$currentTime.tar"

    # save backup image to .tar file
    echo "Save $c backup image to disk"
    docker save -o $backupLocation/$c/$c-backup-$currentDate-$currentTime.tar $c-backup >> /dev/null

    # get size of .tar file
    sizeArray=(`du -s $backupLocation/$c/$c-backup-$currentDate-$currentTime.tar`)
    tarSize=${sizeArray[0]}

    # record compression to log
    write_log "$maintenanceLog" "$containerSize KB compressed to $tarSize KB"

    # remove backup image
    echo "Remove $c backup image"
    docker image rm $c-backup >> /dev/null

    # update container
    cd $containerLocation/${containerDirs[$dirCount]}
    docker-compose pull
    docker-compose up -d

    # backup retention check
    backup_check $c $keepBackups $numBackups ${backupArray[0]} $backupLocation $maintenanceLog

    # record container start to log
    write_log "$maintenanceLog" "updated $c (if available)"

    dirCount=$((dirCount+1))

  done

fi


# clean up old container images
containerImages=$(docker images --quiet --filter "dangling=true")
if [ -n "$containerImages" ]
then
  echo "Removing old container images"
  write_log "$maintenanceLog" "remove old container images: $containerImages"
  docker rmi $containerImages >> /dev/null
fi


# output maintenance completion
write_log "$maintenanceLog" "Maintenance Complete"
echo "" >> $maintenanceLog

echo
echo "-- DOCKER MAINTENANCE COMPLETE --"
echo