backup-github.sh

#!/bin/bash 
# A simple script to backup an organization's GitHub repositories.

GHBU_BACKUP_DIR=${GHBU_BACKUP_DIR-"github-backups"}                  # where to place the backup files
GHBU_ORG=${GHBU_ORG-"autographer"}                                   # the GitHub organization whose repos will be backed up
GHBU_API=${GHBU_API-"https://api.github.com"}                        # base URI for the GitHub API
GHBU_GITHOST=${GHBU_GITHOST-"<CHANGE-ME>.github.com"}                            # the GitHub hostname (see comments)

# I recommend using an API token so it is easily trackable and removable.
# Note that you MUST have SSH keys for a user with the access to all repos set up
GHBU_TOKEN=${GHBU_TOKEN-"<CHANGE-ME>"}  # the token to use for API Authentication
GHBU_GIT_CLONE_CMD="git clone --quiet --mirror git@${GHBU_GITHOST}:" # base command to use to clone GitHub repos
GHBU_APIOPTS="access_token=${GHBU_TOKEN}&"

# You can use Username + Password if you would like
# UNAME+PASSWD must be used if you don't have ssh keys set up
# GHBU_UNAME=${GHBU_UNAME-"<CHANGE-ME>"}                                # the username of a GitHub account (to use with the GitHub API)
# GHBU_PASSWD=${GHBU_PASSWD-"<CHANGE-ME>"}                               # the password for that account 
# GHBU_GIT_CLONE_CMD="git clone --quiet --mirror https://${GHBU_UNAME}:${GHBU_PASSWD}@${GHBU_GITHOST}/" # base command to use to clone GitHub repos
# GHBU_CURLOPTS="-u ${GHBU_UNAME}:${GHBU_PASSWD}"

GHBU_PRUNE_OLD=${GHBU_PRUNE_OLD-true}                                # when `true`, old backups will be deleted
GHBU_PRUNE_AFTER_N_DAYS=${GHBU_PRUNE_AFTER_N_DAYS-3}                 # the min age (in days) of backup files to delete
GHBU_SILENT=${GHBU_SILENT-false}                                     # when `true`, only show error messages 
GHBU_API=${GHBU_API-"https://api.github.com"}                        # base URI for the GitHub API
GHBU_GIT_CLONE_CMD="git clone --mirror git@${GHBU_GITHOST}:" # base command to use to clone GitHub repos

TSTAMP=`date "+%Y%m%d-%H%M"`

# The function `check` will exit the script if the given command fails.
function check {
  "$@"
  status=$?
  if [ $status -ne 0 ]; then
    echo "ERROR: Encountered error (${status}) while running the following:" >&2
    echo "           $@"  >&2
    echo "       (at line ${BASH_LINENO[0]} of file $0.)"  >&2
    echo "       Aborting." >&2
    exit $status
  fi
}

# The function `tgz` will create a gzipped tar archive of the specified file ($1) and then remove the original
function tgz {
   check tar zcf $1.tar.gz $1 && check rm -rf $1
}

$GHBU_SILENT || (echo "" && echo "=== INITIALIZING ===" && echo "")

$GHBU_SILENT || echo "Using backup directory $GHBU_BACKUP_DIR"
check mkdir -p $GHBU_BACKUP_DIR

$GHBU_SILENT || echo "Fetching list of repositories for ${GHBU_ORG}..."

REPOURL="${GHBU_API}/orgs/${GHBU_ORG}/repos?${GHBU_APIOPTS}per_page=2"

REPOLIST=""
while [ $REPOURL ]; do
  REPOREQCONTENT=`curl --silent -i $GHBU_CURLOPTS $REPOURL -q`
  REPOURL=`check echo "${REPOREQCONTENT}" | grep "\"next\"" | check awk -F'<' '{print $2}' | check sed -e 's/>;.*//g'`
  REPOLIST=$REPOLIST`check echo "${REPOREQCONTENT}" | grep "\"name\"" | check awk -F': "' '{print $2}' | check sed -e 's/",//g'`$'\n'
done

# NOTE: if you're backing up a *user's* repos, not an organizations, use this instead:
# REPOLIST=`check curl --silent -u $GHBU_UNAME:$GHBU_PASSWD ${GHBU_API}/user/repos -q | check grep "\"name\"" | check awk -F': "' '{print $2}' | check sed -e 's/",//g'`

$GHBU_SILENT || echo "found `echo $REPOLIST | wc -w` repositories."


$GHBU_SILENT || (echo "" && echo "=== BACKING UP ===" && echo "")

for REPO in $REPOLIST; do
   $GHBU_SILENT || echo "Backing up ${GHBU_ORG}/${REPO}"
   if [ -d "${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.git" ]
   then
      $GHBU_SILENT || echo "Mirror found, Fetching from ${GHBU_ORG}/${REPO}"
      check cd ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.git && git fetch -p origin && cd ../../
   else
      check ${GHBU_GIT_CLONE_CMD}${GHBU_ORG}/${REPO}.git ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.git
   fi

   $GHBU_SILENT || echo "Backing up ${GHBU_ORG}/${REPO}.wiki (if any)"
   ${GHBU_GIT_CLONE_CMD}${GHBU_ORG}/${REPO}.wiki.git ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.wiki-${TSTAMP}.git 2>/dev/null && tgz ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.wiki-${TSTAMP}.git

   $GHBU_SILENT || echo "Backing up ${GHBU_ORG}/${REPO} issues"
   check curl --silent $GHBU_CURLOPTS ${GHBU_API}/repos/${GHBU_ORG}/${REPO}/issues?${GHBU_APIOPTS}state\=all -q > ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.issues-${TSTAMP} && tgz ${GHBU_BACKUP_DIR}/${GHBU_ORG}-${REPO}.issues-${TSTAMP}
done

if $GHBU_PRUNE_OLD; then
  $GHBU_SILENT || (echo "" && echo "=== PRUNING ===" && echo "")
  $GHBU_SILENT || echo "Pruning backup files ${GHBU_PRUNE_AFTER_N_DAYS} days old or older."
  $GHBU_SILENT || echo "Found `find $GHBU_BACKUP_DIR -name '*.tar.gz' -mtime +$GHBU_PRUNE_AFTER_N_DAYS | wc -l` files to prune."
  find $GHBU_BACKUP_DIR -name '*.tar.gz' -mtime +$GHBU_PRUNE_AFTER_N_DAYS -exec rm -fv {} > /dev/null \; 
fi

$GHBU_SILENT || (echo "" && echo "=== DONE ===" && echo "")
$GHBU_SILENT || (echo "GitHub backup completed." && echo "")