Nextcloud Backer-Upper for Calendar/Contacts/Todo lists, with a dash of Git

nc_fetcher.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

# NextCloud Backer-Upper
# Charlton Trezevant, 2021
# This script is provided as-is, under the MIT license.
#
# The purpose of this script is to automatically fetch backup exports of my contacts,
# calendars, and todo lists from Nextcloud.
#
# It grabs these, sorts them into the appropriate directory structure, and checks
# them into Git if the current directory is a repo. If the repo has a remote defined,
# the script will also push the changed files upstream.

require 'net/http'
require 'pathname'
require 'git'

# NextcloudFetcher takes care of authenticating to the NextCloud
# instance, grabbing our data, and organizing it on disk for us.
class NextcloudFetcher
  attr_accessor :dir, :outfile
  attr_writer :username, :password

  def initialize(dir, outfile, uri)
    @dir = dir
    @outfile = outfile
    self.uri = uri
  end

  def fetch
    req = Net::HTTP::Get.new(@uri)
    req.basic_auth @username, @password

    res = Net::HTTP.start(@uri.hostname, @uri.port, use_ssl: true) do |http|
      http.request(req)
    end

    raise("Error contacting server: #{res.code}") unless res.code == '200'

    Dir.mkdir(@dir) unless Dir.exist?(@dir)

    File.open(filename, 'wb') do |file|
      file.write(res.body)
    end
  end

  def filename
    Pathname.new("#{dir}/#{outfile}")
  end

  def uri=(uri)
    @uri = URI(uri)
  end
end

def save_to_git
  puts 'Committing changes to Git...'

  g = Git.open(Dir.getwd)
  g.add(all: true)

  time = Time.new
  g.commit_all("Backups for #{time.year}/#{time.month}/#{time.day} at #{time.hour}:#{time.min}")

  g.push unless g.remotes.empty?
end

def git_repo?
  File.directory?("#{Dir.getwd}/.git")
end

backups = [
  ['Contacts', 'My Contacts.vcf', 'https://nextcloud.example.org/remote.php/dav/addressbooks/users/username/contacts/?export'],
  ['Calendars', 'My Calendar.ics', 'https://nextcloud.example.org/remote.php/dav/calendars/username/calendar_name/?export']
]

backups.each do |item|
  fetcher = NextcloudFetcher.new(item[0], item[1], item[2])

  fetcher.username = ENV['NC_USER']
  fetcher.password = ENV['NC_PASS']

  puts "Fetching #{fetcher.filename}..."

  fetcher.fetch
end

save_to_git if git_repo?

puts 'Backup finished.'