zfsbackupcleaner/main.cpp

233 lines
8.1 KiB
C++

#include <boost/date_time/posix_time/posix_time_config.hpp>
#include <boost/date_time/posix_time/posix_time_types.hpp>
#include <boost/date_time/posix_time/time_formatters.hpp>
#include <boost/date_time/posix_time/time_parsers.hpp>
#include <boost/program_options/options_description.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/program_options/positional_options.hpp>
#include <boost/program_options/variables_map.hpp>
#include <iostream>
#include <boost/process.hpp>
#include <boost/process/v2/stdio.hpp>
#include <boost/process/v2/environment.hpp>
#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <iterator>
#include <set>
#include <boost/program_options.hpp>
#include <boost/filesystem.hpp>
namespace bp = boost::process;
namespace asio = boost::asio;
namespace po = boost::program_options;
namespace fs = boost::filesystem;
class zfsbackupcleaner
{
public:
zfsbackupcleaner(std::string backupsystem): _backupsystem(backupsystem), _now(boost::posix_time::second_clock::local_time()), _dry_run(false)
{
std::cout << "Gehe aus von aktueller Zeit: " << _now << std::endl << std::endl;
}
void set_dry_run(bool val = true) { _dry_run = val; }
void read_backups()
{
asio::io_context ctx;
asio::readable_pipe out(ctx);
bp::process proc(ctx, bp::environment::find_executable("zfs"), {"list", "-t", "snapshot", "/backup/"+_backupsystem}, bp::process_stdio{{/* in to default*/}, out, {/* err to default */}});
std::string output;
boost::system::error_code ec;
asio::read(out, asio::dynamic_buffer(output), ec);
assert(!ec || (ec==asio::error::eof));
proc.wait();
std::stringstream lines(output);
for(std::string line; std::getline(lines, line);)
{
std::string::size_type pos = line.find(' ');
line = line.substr(0,pos);
//std::cout << "X: " << line << std::endl;
if(line == "NAME")
continue;
pos = line.find('@');
_backupbase = line.substr(0,pos);
std::string timestring = line.substr(pos+1);
timestring[10]=' ';
timestring[13]=':';
timestring[16]=':';
boost::posix_time::ptime t(boost::posix_time::time_from_string(timestring));
_backuptimes.insert(t);
}
}
void clean_backups ()
{
if(_backuptimes.empty())
{
std::cout << "Keine Backups für >" << _backupsystem << "< gefunden." << std::endl << "Keine weitere Behandlung." << std::endl;
return;
}
if(_backuptimes.size() < 7)
{
std::cout << "Weniger als 7 Backups für >" << _backupsystem << "< gefunden." << std::endl << "Keine weitere Behandlung." << std::endl;
return;
}
// Hinweis: Die Backups werden so von "zfs list" übermittelt, dass das älteste am Anfang steht und das jüngste am Ende der Liste
_iter_current=_backuptimes.begin();
_iter_last_to_handle = _backuptimes.end();
std::advance(_iter_last_to_handle, -7); // Die letzten sieben Backups werden besonders behandelt - sie bleiben in jedem Fall erhalten!
// Nun von hinten her die Backups durchgehen
// A) Das allererste Backup behalten wir in jedem Fall
std::cout << "Behalte allererstes Backup " << *_iter_current << " in diesem Backup-Set." << std::endl << std::endl;
_iter_current++;
// B) after 365 days, we keep one backup every 30 days
handle_backups<30,365>();
// C) after 30 days, we keep one backup every 7 days
handle_backups<7,30>();
// D) after one day, we keep one backup per day
handle_backups<1,1>();
// E) Behalte die letzten bis zu sieben Backups
for(; _iter_current != _backuptimes.end(); _iter_current++)
{
std::cout << "Behalte Backup " << *_iter_current << ", weil es zu den letzten 7 gehört." << std::endl;
}
}
private:
template<int keep_every_x_days,int after_y_day> void handle_backups()
{
if(_iter_current == _iter_last_to_handle)
return;
boost::gregorian::date_duration dur;
boost::posix_time::ptime last_kept_time;
while( _iter_current != _iter_last_to_handle && (dur = _now.date() - _iter_current->date()) > boost::gregorian::days(after_y_day))
{
last_kept_time = *_iter_current;
std::cout << "Behalte Backup " << last_kept_time << " [Älter als " << after_y_day << ", Backup alle " << keep_every_x_days << " Tage behalten]." << std::endl << std::endl;
_iter_current++;
while( _iter_current != _iter_last_to_handle && (dur = _iter_current->date() - last_kept_time.date()) < boost::gregorian::days(keep_every_x_days))
{
std::cout << "Entferne Backup " << *_iter_current << " weil wir bereits eines im aktuellen Zyklus haben [Älter als " << after_y_day << ", Backup alle " << keep_every_x_days << " Tage behalten]." << std::endl;
if(!_dry_run)
{
std::string timestring = boost::posix_time::to_iso_extended_string(*_iter_current);
timestring[10]='_';
timestring[13]='-';
timestring[16]='-';
timestring=timestring.substr(0, 19);
asio::io_context ctx;
asio::readable_pipe out(ctx);
std::vector<std::string> args;
args.push_back("destroy");
args.push_back("-v");
if(_dry_run)
args.push_back("-n");
args.push_back(_backupbase + "@" + timestring);
bp::process proc(ctx, bp::environment::find_executable("zfs"), args, bp::process_stdio{{/* in to default*/}, out, {/* err to default */}});
std::string output;
boost::system::error_code ec;
asio::read(out, asio::dynamic_buffer(output), ec);
assert(!ec || (ec==asio::error::eof));
proc.wait();
std::cout << output << std::endl;
}
_iter_current++;
}
}
}
std::string _backupsystem;
boost::posix_time::ptime _now;
bool _dry_run;
std::string _backupbase;
std::set<boost::posix_time::ptime> _backuptimes;
std::set<boost::posix_time::ptime>::iterator _iter_current;
std::set<boost::posix_time::ptime>::iterator _iter_last_to_handle;
};
int main(int argc, char** argv){
std::cout << "Hello, from zfsbackupcleaner!\n";
po::options_description options("Argumente");
options.add_options()
("help", "Hilfe anzeigen")
("dry-run,n", "Test-Modus; keine Backups entfernen")
("backupsystem", po::value<std::string>(), "Computer, dessen Backups bereinigt werden sollen")
;
po::positional_options_description p;
p.add("backupsystem", 1);
po::variables_map vm;
try {
po::store(po::command_line_parser(argc,argv).options(options).positional(p).run(), vm);
po::notify(vm);
} catch (const boost::program_options::invalid_command_line_syntax & error) {
std::cout << "Error parsing commandline-arguments:" << std::endl;
std::cout << error.what() << std::endl;
return -1;
}
if(vm.count("help") || !vm.count("backupsystem"))
{
std::cout << "Benutzung: zfsbackupcleaner [Optionen] <Backupsystem>" << std::endl << std::endl;
std::cout << options << std::endl;
return 0;
}
std::string backupsystem = vm["backupsystem"].as<std::string>();
if(backupsystem != "workstation" && ! fs::exists("/backup/"+backupsystem))
{
std::cout << "Für das System >" << backupsystem << "< gibt es keine Backups." << std::endl;
return -1;
}
zfsbackupcleaner zbc(backupsystem);
if(vm.count("dry-run"))
zbc.set_dry_run(true);
zbc.read_backups();
zbc.clean_backups();
return 0;
}