Why does Zipping the same content twice gives two files with different SHA1?

Question

I have run into a strange problem with git and zip files. My build script takes a bunch of documentation html pages and zips them into a docs.zip I then check this file into

Answer 1

Use below script to create deterministic zip or jar files

#!/bin/bash

usage() {
    echo "Usage : ./createDeterministicArtifact.sh "
    exit 1
}

info() {
    echo "$1"
}

strip_artifact() {
    if [ -z ${file} ]; then
        usage
    fi
    if [ -f ${file} -a -s ${file} ]; then
        mkdir -p ${file}.tmp
        unzip -oq -d ${file}.tmp ${file}
        find ${file}.tmp -follow -exec touch -a -m -t 201912010000.00 {} \+
        if [ "$UNAME" == "Linux" ] ; then
            find ${file}.tmp -follow -exec chattr -a {} \+
        elif [[ "$UNAME" == CYGWIN* || "$UNAME" == MINGW* ]] ; then
            find ${file}.tmp -follow -exec attrib -A {} \+
        fi
        cd ${file}.tmp
        zip -rq -D -X -9 -A --compression-method deflate  ../${file}.new . 
        cd -
        rm -rf ${file}.tmp
        info "Recreated deterministic artifact: ${file}.new"
    else 
        info "Input file is empty. Please validate the file and try again"
    fi
}

file=$1
strip_artifact