This is a bash script designed for backing up every repo in a github organization and encrypted the repo archives.

archive-org.sh

#!/usr/bin/env bash -e

organization=$1

if [ -z $organization ]; then
  echo "Usage: $0 <organization>"
  echo
  echo "Make sure to specify \$GITHUB_API_TOKEN as an environment variable."
  echo "Acquire one here: https://github.com/settings/tokens"
  echo
  echo "Also required \$BACKUP_PASSWORD_FILE containing a password for AES encryption."
  echo
  exit 1
fi

mkdir -p repos/$organization archives/$organization

page=1

while :
do
  repos=`curl -s "https://api.github.com/orgs/$organization/repos?page=$page&per_page=100&access_token=$GITHUB_API_TOKEN" | jq '.[].ssh_url' | sed -e 's/^"//' -e 's/"$//'`
  if [ -z "$repos" ]; then
    break
  fi

  for ssh_url in $repos;
  do
    repo=`basename $ssh_url`
    clone="repos/$organization/${repo%.*}"
    archive="archives/$organization/${repo%.*}.tar"
    bundle="$archive.aes"

    if [ ! -e "$bundle" ]; then
      git clone --mirror "$ssh_url" "$clone"
      tar -cvf "$archive" "$clone"
      openssl aes-256-cbc -pass file:$BACKUP_PASSWORD_FILE -salt -in "$archive" -out "$bundle"
    fi
  done

  page=$((page+1))
done