discourse/lib/backup_restore/restorer.rb

454 lines
13 KiB
Ruby

module BackupRestore
class RestoreDisabledError < RuntimeError; end
class FilenameMissingError < RuntimeError; end
class Restorer
include BackupRestore::Utils
attr_reader :success
def initialize(user_id, opts={})
@user_id = user_id
@client_id = opts[:client_id]
@filename = opts[:filename]
@publish_to_message_bus = opts[:publish_to_message_bus] || false
ensure_restore_is_enabled
ensure_no_operation_is_running
ensure_we_have_a_user
ensure_we_have_a_filename
initialize_state
end
def run
log "[STARTED]"
log "'#{@user_info[:username]}' has started the restore!"
mark_restore_as_running
listen_for_shutdown_signal
ensure_directory_exists(@tmp_directory)
copy_archive_to_tmp_directory
unzip_archive
extract_metadata
validate_metadata
extract_dump
restore_dump
### READ-ONLY / START ###
enable_readonly_mode
pause_sidekiq
wait_for_sidekiq
switch_schema!
migrate_database
reconnect_database
reload_site_settings
clear_emoji_cache
disable_readonly_mode
### READ-ONLY / END ###
extract_uploads
rescue SystemExit
log "Restore process was cancelled!"
rollback
rescue => ex
log "EXCEPTION: " + ex.message
log ex.backtrace.join("\n")
rollback
else
@success = true
ensure
begin
notify_user
clean_up
rescue => ex
Rails.logger.error("#{ex}\n" + ex.backtrace.join("\n"))
end
@success ? log("[SUCCESS]") : log("[FAILED]")
end
protected
def ensure_restore_is_enabled
raise BackupRestore::RestoreDisabledError unless Rails.env.development? || SiteSetting.allow_restore?
end
def ensure_no_operation_is_running
raise BackupRestore::OperationRunningError if BackupRestore.is_operation_running?
end
def ensure_we_have_a_user
user = User.find_by(id: @user_id)
raise Discourse::InvalidParameters.new(:user_id) unless user
# keep some user data around to check them against the newly restored database
@user_info = { id: user.id, username: user.username, email: user.email }
end
def ensure_we_have_a_filename
raise BackupRestore::FilenameMissingError if @filename.nil?
end
def initialize_state
@success = false
@db_was_changed = false
@current_db = RailsMultisite::ConnectionManagement.current_db
@current_version = BackupRestore.current_version
@timestamp = Time.now.strftime("%Y-%m-%d-%H%M%S")
@tmp_directory = File.join(Rails.root, "tmp", "restores", @current_db, @timestamp)
@source_filename = File.join(Backup.base_directory, @filename)
@archive_filename = File.join(@tmp_directory, @filename)
@tar_filename = @archive_filename[0...-3]
@meta_filename = File.join(@tmp_directory, BackupRestore::METADATA_FILE)
@is_archive = !(@filename =~ /.sql.gz$/)
# For backwards compatibility
@dump_filename =
if @is_archive
if system("tar --list --file #{@source_filename} #{BackupRestore::OLD_DUMP_FILE}")
File.join(@tmp_directory, BackupRestore::OLD_DUMP_FILE)
else
File.join(@tmp_directory, BackupRestore::DUMP_FILE)
end
else
File.join(@tmp_directory, @filename)
end
@logs = []
@readonly_mode_was_enabled = Discourse.readonly_mode?
end
def listen_for_shutdown_signal
Thread.new do
while BackupRestore.is_operation_running?
exit if BackupRestore.should_shutdown?
sleep 0.1
end
end
end
def mark_restore_as_running
log "Marking restore as running..."
BackupRestore.mark_as_running!
end
def enable_readonly_mode
return if @readonly_mode_was_enabled
log "Enabling readonly mode..."
Discourse.enable_readonly_mode
end
def pause_sidekiq
log "Pausing sidekiq..."
Sidekiq.pause!
end
def wait_for_sidekiq
log "Waiting for sidekiq to finish running jobs..."
iterations = 1
while sidekiq_has_running_jobs?
log "Waiting for sidekiq to finish running jobs... ##{iterations}"
sleep 5
iterations += 1
raise "Sidekiq did not finish running all the jobs in the allowed time!" if iterations > 6
end
end
def sidekiq_has_running_jobs?
Sidekiq::Workers.new.each do |_, _, worker|
payload = worker.try(:payload)
return true if payload.try(:all_sites)
return true if payload.try(:current_site_id) == @current_db
end
false
end
def copy_archive_to_tmp_directory
log "Copying archive to tmp directory..."
execute_command("cp '#{@source_filename}' '#{@archive_filename}'", "Failed to copy archive to tmp directory.")
end
def unzip_archive
return unless @is_archive
log "Unzipping archive, this may take a while..."
FileUtils.cd(@tmp_directory) do
execute_command("gzip --decompress '#{@archive_filename}'", "Failed to unzip archive.")
end
end
def extract_metadata
log "Extracting metadata file..."
@metadata =
if system("tar --list --file #{@source_filename} #{BackupRestore::METADATA_FILE}")
FileUtils.cd(@tmp_directory) do
execute_command(
"tar --extract --file '#{@tar_filename}' #{BackupRestore::METADATA_FILE}",
"Failed to extract metadata file."
)
end
data = Oj.load_file(@meta_filename)
raise "Failed to load metadata file." if !data
data
else
if @filename =~ /-#{BackupRestore::VERSION_PREFIX}(\d{14})/
{ "version" => Regexp.last_match[1].to_i }
else
raise "Migration version is missing from the filename."
end
end
end
def validate_metadata
log "Validating metadata..."
log " Current version: #{@current_version}"
raise "Metadata has not been extracted correctly." if !@metadata
log " Restored version: #{@metadata["version"]}"
error = "You're trying to restore a more recent version of the schema. You should migrate first!"
raise error if @metadata["version"] > @current_version
end
def extract_dump
return unless @is_archive
log "Extracting dump file..."
FileUtils.cd(@tmp_directory) do
execute_command(
"tar --extract --file '#{@tar_filename}' #{File.basename(@dump_filename)}",
"Failed to extract dump file."
)
end
end
def restore_dump_command
if File.extname(@dump_filename) == '.gz'
"gzip -d < #{@dump_filename} | #{sed_command} | #{psql_command} 2>&1"
else
"#{psql_command} 2>&1 < #{@dump_filename}"
end
end
def restore_dump
log "Restoring dump file... (can be quite long)"
logs = Queue.new
psql_running = true
has_error = false
Thread.new do
RailsMultisite::ConnectionManagement::establish_connection(db: @current_db)
while psql_running
message = logs.pop.strip
has_error ||= (message =~ /ERROR:/)
log(message) unless message.blank?
end
end
IO.popen(restore_dump_command) do |pipe|
begin
while line = pipe.readline
logs << line
end
rescue EOFError
# finished reading...
ensure
psql_running = false
logs << ""
end
end
# psql does not return a valid exit code when an error happens
raise "psql failed" if has_error
end
def psql_command
db_conf = BackupRestore.database_configuration
password_argument = "PGPASSWORD=#{db_conf.password}" if db_conf.password.present?
host_argument = "--host=#{db_conf.host}" if db_conf.host.present?
port_argument = "--port=#{db_conf.port}" if db_conf.port.present?
username_argument = "--username=#{db_conf.username}" if db_conf.username.present?
[ password_argument, # pass the password to psql (if any)
"psql", # the psql command
"--dbname='#{db_conf.database}'", # connect to database *dbname*
"--single-transaction", # all or nothing (also runs COPY commands faster)
host_argument, # the hostname to connect to (if any)
port_argument, # the port to connect to (if any)
username_argument # the username to connect as (if any)
].join(" ")
end
def sed_command
# in order to limit the downtime when restoring as much as possible
# we force the restoration to happen in the "restore" schema
# during the restoration, this make sure we
# - drop the "restore" schema if it exists
# - create the "restore" schema
# - prepend the "restore" schema into the search_path
regexp = "SET search_path = public, pg_catalog;"
replacement = [ "DROP SCHEMA IF EXISTS restore CASCADE;",
"CREATE SCHEMA restore;",
"SET search_path = restore, public, pg_catalog;",
].join(" ")
# we only want to replace the VERY first occurence of the search_path command
expression = "1,/^#{regexp}$/s/#{regexp}/#{replacement}/"
"sed -e '#{expression}'"
end
def switch_schema!
log "Switching schemas... try reloading the site in 5 minutes, if successful, then reboot and restore is complete."
sql = [
"BEGIN;",
BackupRestore.move_tables_between_schemas_sql("public", "backup"),
BackupRestore.move_tables_between_schemas_sql("restore", "public"),
"COMMIT;"
].join("\n")
@db_was_changed = true
User.exec_sql(sql)
end
def migrate_database
log "Migrating the database..."
Discourse::Application.load_tasks
ENV["VERSION"] = @current_version.to_s
User.exec_sql("SET search_path = public, pg_catalog;")
Rake::Task["db:migrate"].invoke
end
def reconnect_database
log "Reconnecting to the database..."
RailsMultisite::ConnectionManagement::establish_connection(db: @current_db)
end
def reload_site_settings
log "Reloading site settings..."
SiteSetting.refresh!
end
def clear_emoji_cache
log "Clearing emoji cache..."
Emoji.clear_cache
end
def extract_uploads
if system("tar --list --file '#{@tar_filename}' 'uploads'")
log "Extracting uploads..."
FileUtils.cd(File.join(Rails.root, "public")) do
execute_command(
"tar --extract --keep-newer-files --file '#{@tar_filename}' uploads/",
"Failed to extract uploads."
)
end
end
end
def rollback
log "Trying to rollback..."
if @db_was_changed && BackupRestore.can_rollback?
log "Rolling back..."
BackupRestore.move_tables_between_schemas("backup", "public")
else
log "There was no need to rollback"
end
end
def notify_user
if user = User.find_by(email: @user_info[:email])
log "Notifying '#{user.username}' of the end of the restore..."
if @success
SystemMessage.create_from_system_user(user, :restore_succeeded, logs: pretty_logs(@logs))
else
SystemMessage.create_from_system_user(user, :restore_failed, logs: pretty_logs(@logs))
end
else
log "Could not send notification to '#{@user_info[:username]}' (#{@user_info[:email]}), because the user does not exists..."
end
end
def clean_up
log "Cleaning stuff up..."
remove_tmp_directory
unpause_sidekiq
disable_readonly_mode if Discourse.readonly_mode?
mark_restore_as_not_running
log "Finished!"
end
def remove_tmp_directory
log "Removing tmp '#{@tmp_directory}' directory..."
FileUtils.rm_rf(@tmp_directory) if Dir[@tmp_directory].present?
rescue
log "Something went wrong while removing the following tmp directory: #{@tmp_directory}"
end
def unpause_sidekiq
log "Unpausing sidekiq..."
Sidekiq.unpause!
rescue
log "Something went wrong while unpausing Sidekiq."
end
def disable_readonly_mode
return if @readonly_mode_was_enabled
log "Disabling readonly mode..."
Discourse.disable_readonly_mode
end
def mark_restore_as_not_running
log "Marking restore as finished..."
BackupRestore.mark_as_not_running!
end
def ensure_directory_exists(directory)
log "Making sure #{directory} exists..."
FileUtils.mkdir_p(directory)
end
def log(message)
timestamp = Time.now.strftime("%Y-%m-%d %H:%M:%S")
puts(message) rescue nil
publish_log(message, timestamp) rescue nil
save_log(message, timestamp)
end
def publish_log(message, timestamp)
return unless @publish_to_message_bus
data = { timestamp: timestamp, operation: "restore", message: message }
MessageBus.publish(BackupRestore::LOGS_CHANNEL, data, user_ids: [@user_id], client_ids: [@client_id])
end
def save_log(message, timestamp)
@logs << "[#{timestamp}] #{message}"
end
end
end