nc-sync

#!/usr/bin/env bash
set -euo pipefail

workdir="/home/jovyan/drive"
workspace="/workspace"

NC_SYNC_INTERVAL="${NC_SYNC_INTERVAL:-60s}"
NC_SYNC_BACKOFF="${NC_SYNC_BACKOFF:-300s}"
NC_SYNC_TIMEOUT="${NC_SYNC_TIMEOUT:-6h}"

rmdir --ignore-fail-on-non-empty /home/jovyan/work || true

mkdir -p "${workdir}"

if [[ ! -d "${workspace}" ]]; then
  echo "[nc-sync] ERROR: ${workspace} does not exist"
  exit 1
fi

cd "${workspace}"

if [[ -e drive && ! -L drive ]]; then
  echo "[nc-sync] ERROR: ${workspace}/drive exists but is not a symlink"
  exit 1
fi

if [[ ! -L drive ]]; then
  ln -s "${workdir}" drive
fi

server="http://${NEXTCLOUD_HOST:-localhost:8081}"
json_file="${workdir}/.access_token.json"

# Exclude eodata from Nextcloud sync
exclude_file="${workdir}/.sync-exclude.lst"
cat > "${exclude_file}" <<'EOF'
eodata
eodata/*
EOF

refresh_token() {
  local json token expires_at

  json=""

  if [[ -n "${JUPYTERHUB_API_TOKEN:-}" && -n "${JUPYTER_HOST:-}" ]]; then
    json="$(curl -fsS \
      --header "Authorization: token ${JUPYTERHUB_API_TOKEN}" \
      "http://${JUPYTER_HOST}/services/refresh-token/tokens" || true)"
  fi

  if [[ -z "${json}" || "$(echo "${json}" | jq -r '.access_token // empty' 2>/dev/null)" == "" ]]; then
    if [[ -z "${NEXTCLOUD_ACCESS_TOKEN:-}" ]]; then
      echo "[nc-sync] ERROR: unable to refresh token and NEXTCLOUD_ACCESS_TOKEN is not set" >&2
      return 1
    fi

    token="${NEXTCLOUD_ACCESS_TOKEN}"
    expires_at="$(date -d "10 min" +%s)"

    json="$(jq -n \
      --arg token "${token}" \
      --argjson expires "${expires_at}" \
      '{access_token: $token, token_expires: $expires}')"
  fi

  echo "${json}" > "${json_file}"

  jq -r '.access_token // empty' "${json_file}"
}

get_token() {
  local now token expires_at

  if [[ -f "${json_file}" ]] && jq empty "${json_file}" >/dev/null 2>&1; then
    now="$(date +%s)"
    token="$(jq -r '.access_token // empty' "${json_file}")"
    expires_at="$(jq -r '.token_expires // 0' "${json_file}" | sed 's/\..*//')"

    if [[ -z "${token}" || ! "${expires_at}" =~ ^[0-9]+$ || "${expires_at}" -lt "${now}" ]]; then
      refresh_token
    else
      echo "${token}"
    fi
  else
    refresh_token
  fi
}

ncsync() {
  while true; do
    token="$(get_token || true)"

    if [[ -n "${token}" && "${token}" != "null" && -n "${JUPYTERHUB_USER:-}" ]]; then
      echo "[nc-sync] starting sync"

      if timeout "${NC_SYNC_TIMEOUT}" nextcloudcmd -n -s \
        --user "${JUPYTERHUB_USER}" \
        --password "${token}" \
        --exclude "${exclude_file}" \
        --path / \
        "${workdir}" \
        "${server}"; then
        echo "[nc-sync] sync completed"
        sleep "${NC_SYNC_INTERVAL}"
      else
        echo "[nc-sync] WARNING: sync failed or timed out, backing off"
        sleep "${NC_SYNC_BACKOFF}"
      fi
    else
      echo "[nc-sync] missing token or user, skipping sync"
      sleep "${NC_SYNC_BACKOFF}"
    fi
  done
}

ncsync &