Update CHANGELOG adding all previous commits subject by default

update_changelog.sh

#!/bin/bash 

current_tag=production_$(date +'%Y%m%d')
git tag $current_tag

previous_tag=$(git tag -l 'prod*' --sort=-committerdate | grep -v $current_tag | head -n1)
commit_description=$(git log $previous_tag..$current_tag --pretty=format:" * %s")

if ! [ -f CHANGELOG.md ]; then touch CHANGELOG.md; fi;
  
cat << EOF > CHANGELOG.md
${current_tag}
===================

${commit_description}

$(cat CHANGELOG.md)
EOF