a script for replace base image

docker-replace-base-image.sh

#!/bin/bash
# a script for replace base image 
# using "docker history --no-trunc base-image-tag "  to found the right base base-image-id
if [ -z "$1" -o -z "$2" -o -z "$3" ] ; then
 echo 'usage:'
 echo ' replace supper image id:'
 echo '    1. using "docker history --no-trunc base-image-tag "  to found the right base image id need to be replaced'
 echo '    2.  docker-replace-base-image.sh  registry-store-location sub-image-tag base-image-id super-base-image-id '
 echo ' or if  sub-image-parent-id need replaced with base-image-id:'
 echo '   docker-replace-base-image.sh  registry-store-location sub-image-tag base-image-tag '
 
 exit
fi 


 storeDir="$1"
 repoDir="$storeDir/repositories"
 imgDir="$storeDir/images"
 baseImg="$3"
 subimg="$2"
 tmpDir=$(mktemp -d -t tmp-images-XXXX)
 
 
 echo "registry store dir:$storeDir"
 echo "sub image tag(the one need to upgrade base image):$subimg"
 echo "base image id / tag :$baseImg"
 echo "tmp dir:$tmpDir" 
 if [ -z "$4" -o ${#4} -eq 64 ] ; then
  echo "super base image id:$4" 
  #oldImgId="$4"
 else
  echo "illegal old-base-imgage-id:$4"
  exit -1;
 fi

 echo "Are you sure ?[Y=yes]"
 read ok

if [ "$ok" = "Y" ] ; then 
 
 rm -rf $tmpDir && mkdir $tmpDir

 if [ ${#baseImg} -ne 64 ] ; then 
   baseImgId=$(cat $repoDir/$baseImg/tag_latest)
 else
   baseImgId=$baseImg
 fi
 echo "base-image-id:$baseImgId"

 #current base image ancestry json  array
 currentImagAncestry=$(jq '.' $imgDir/$baseImgId/ancestry )
# echo "currentImagAncestry:$currentImagAncestry" 

 subimgId=$(cat $repoDir/$subimg/tag_latest)
 echo "sub-image-id:$subimgId"

 #find parent image id
 subImgParentId=$( jq '.parent' $imgDir/$subimgId/json | sed 's#"##g' )
 echo "sub image parent id : $subImgParentId"
 


 if [ -z "$4" -o ${#4} -eq 64 ] ; then
   vjson="$imgDir/$4/json"   
 else 
   vjson="$imgDir/$subimgId/json"
   oldImgId=$subImgParentId
 fi


 if [ -z "$oldImgId" ] ; then
   oldImgId=$( jq '.parent' $vjson | sed 's#"##g' )
 fi

 echo "old-base-image-id: $oldImgId"
 
 if [ "$oldImgId" = "$baseImgId" ] ; then
   echo "old-base-image-id == base-image-id ,do nothing!"
   exit
 #else
 # exit
 fi  
 


 #find the old base image ancestry json array
 oldImgAncestry=$(jq '.' $imgDir/$oldImgId/ancestry )
# echo "oldImgAncestry:$oldImgAncestry"


 #update image ancestry
 jq "  .  - $oldImgAncestry + $currentImagAncestry " $imgDir/$subimgId/ancestry > $tmpDir/ancestry


 CID="$subimgId"
 #update image parent
 newParentFilter=". + {\"parent\": \"$baseImgId\"}"
 echo $newParentFilter
 jq "$newParentFilter" $vjson > $tmpDir/json

 #update image index
 jq " [.[].id] - $oldImgAncestry + $currentImagAncestry" $repoDir/$subimg/_index_images | jq '[ .[] | {id: .} ]' >  $tmpDir/_index_images

echo "Are you sure to replace ?[Y=yes]"
 read ok
 if [ "$ok" = "Y" ] ; then
 
 echo "for safety,backup to $storeDir/backup,if there are problems restore it!"
 echo "restore steps:"
 echo "cp $storeDir/backup/$subimg/_index_images  $repoDir/$subimg/ "
 echo "cp $storeDir/backup/$subimg/ancestry $imgDir/$CID/ "
 echo "cp $storeDir/backup/$subimg/json $vjson "


 mkdir -p $storeDir/backup/$subimg
 cp $repoDir/$subimg/_index_images $storeDir/backup/$subimg/
 cp $imgDir/$CID/ancestry $storeDir/backup/$subimg/
 cp $vjson $storeDir/backup/$subimg/

 echo "do replace..."
  
 #create new image and update tag_latest to new image
  #echo "create new image:$CID" 
 # mkdir $imgDir/$CID  
 # cp -r $imgDir/$subimgId/* $imgDir/$CID && \
  cp $tmpDir/ancestry $imgDir/$CID/ancestry 
  
  cp $tmpDir/json  $vjson 
  cp $tmpDir/_index_images  $repoDir/$subimg/_index_images 
#  rm -rf $tmpDir 
  echo "replace ok! you need delete local image(docker rmi) and pull it again!"
  exit
 fi
fi

echo "do nothing"

if your image app was portable ,using "docker-merge-image-dir" script will be better
https://gist.github.com/qxo/35b5fc84a3a200ed3707