clean-branches.sh

#!/usr/bin/env bash

while test $# -gt 0; do
       case "$1" in
            -h|--help)
                echo "Options:"
                echo "-r      github repository name, together with user or organization, e.g. fabric8io/kubernetes-model"              
                echo "-t      github token (https://github.com/settings/tokens)"
                exit 0
                ;;
            -r)
                shift
                if test $# -gt 0; then
                    REPO_NAME=$1
                    DIR=$(echo $1 | cut -d '/' -f 2)
                fi
                shift
                ;;       
            -t)
                shift
                if test $# -gt 0; then
                    TOKEN=$1
                fi
                shift
                ;;
            *)
               echo "$1 is not a recognized flag!"
               exit -1
               ;;
      esac
done

TOKEN_HEADER="Authorization:token ${TOKEN}"
NEXT_LINK="https://api.github.com/repos/${REPO_NAME}/branches"

while [ ! -z "${NEXT_LINK// }" ]; do

    branches=$(http ${NEXT_LINK} "${TOKEN_HEADER}" | jq -c '[.[] | select(.name | startswith("versionUpdate")) | .name ]')
    
    while read -r branch 
    do
        http DELETE https://api.github.com/repos/${REPO_NAME}/git/refs/heads/${branch} "${TOKEN_HEADER}"
    done < <(jq -cr '.[]' <<<"${branches}")
       
    NEXT_LINK=$(http --print=h ${NEXT_LINK} "${TOKEN_HEADER}" | grep -Eo '<.*>; rel="next"' | cut -d';' -f1 | sed 's/<\(.*\)>/\1/p' -n)
done

Prerequisite

sudo dnf install httpie jq

GitHub token - read/write to org or repo

Execution

./clean-branches.sh -r fabric8-ui/fabric8-planner -t TOKEN