mergerfs/src/mergerfs_collect_info.cpp

/*
  ISC License

  Copyright (c) 2026, Antonio SJ Musumeci <trapexit@spawn.link>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "mergerfs_collect_info.hpp"

#include "mergerfs_api.hpp"
#include "fs_mounts.hpp"
#include "fs_unlink.hpp"

#include "CLI11/CLI11.hpp"
#include "fmt/core.h"
#include "fmt/ranges.h"
#include "scope_guard.hpp"
#include "subprocess/subprocess.hpp"

#include <stdio.h>


static
void
_write_str(const std::string &output_,
           const std::string &str_)
{
  FILE *f;

  f = ::fopen(output_.c_str(),"a");
  if(f == NULL)
    return;
  DEFER{ ::fclose(f); };

  ::fwrite(str_.c_str(),1,str_.size(),f);
}

static
void
_run(const std::initializer_list<const char*> &args_,
     const std::string                        &output_)
{
  std::string hdr;

  hdr = fmt::format("=== {}\n",fmt::join(args_," "));
  try
    {
      _write_str(output_,hdr);
      subprocess::call(args_,
                       subprocess::output{output_.c_str()});
    }
  catch(...)
    {
      ::_write_str(output_,"error: command failed to run\n");
    }

  _write_str(output_,"\n\n");
}

static
void
_lsblk(const std::string &output_)
{
  auto args =
    {
      "lsblk",
      "--json",
      "-o","NAME,FSTYPE,FSSIZE,SIZE,MOUNTPOINTS,RM,RO,ROTA"
    };

  ::_run(args,output_);
}

static
void
_mounts(const std::string &output_)
{
  ::_run({"cat","/proc/mounts"},output_);
}

static
void
_mount_point_stats(const std::string &output_)
{
  fs::MountVec mounts;

  fs::mounts(mounts);

  for(const auto &mount : mounts)
    {
      std::vector<std::string> allpaths;

      mergerfs::api::allpaths(mount.dir.string(),allpaths);
      for(const auto &path : allpaths)
        {
          ::_run({"stat",path.c_str()},output_);
        }
    }
}

static
void
_mergerfs_version(const std::string &output_)
{
  ::_run({"mergerfs","--version"},output_);
}

static
void
_mergerfs_settings(const std::string &output_)
{
  fs::MountVec mounts;

  fs::mounts(mounts);

  for(const auto &mount : mounts)
    {
      int rv;
      std::map<std::string,std::string> kvs;

      rv = mergerfs::api::get_kvs(mount.dir.string(),&kvs);
      if(rv < 0)
        continue;

      std::string output_str;

      output_str = fmt::format("=== {}/.mergerfs\n",mount.dir.string());
      for(const auto &[k,v] : kvs)
        output_str += fmt::format("{}={}\n",k,v);
      output_str += "\n\n";

      _write_str(output_,output_str);
    }
}

static
void
_uname(const std::string &output_)
{
  ::_run({"uname","-a"},output_);
}

static
void
_lsb_release(const std::string &output_)
{
  ::_run({"lsb_release","-a"},output_);
}

static
void
_df(const std::string &output_)
{
  ::_run({"df","-h"},output_);
}

static
void
_fstab(const std::string &output_)
{
  ::_run({"cat","/etc/fstab"},output_);
}

static
void
_software_versions(const std::string &output_)
{
  ::_run({"docker","--version"},output_);
  ::_run({"docker","compose","--version"},output_);
  ::_run({"podman","--version"},output_);
  ::_run({"podman","compose","--version"},output_);
  ::_run({"smbd","--version"},output_);
}

static
void
_lshw(const std::string &output_)
{
  ::_run({"lshw"},output_);
}

static
void
_journalctl(const std::string &output_)
{
  ::_run({"journalctl","-t","mergerfs","--since","60 minutes ago"},output_);
}

int
mergerfs::collect_info::main(int    argc_,
                             char **argv_)
{
  CLI::App app;
  const char *output_filepath = "/tmp/mergerfs.info.txt";

  app.description("mergerfs.collect-info:"
                  " Collect info for support requests");
  app.name("USAGE: mergerfs.collect-info");

  try
    {
      app.parse(argc_,argv_);
    }
  catch(const CLI::ParseError &e)
    {
      return app.exit(e);
    }

  fmt::print("* Please have mergerfs mounted before running this tool.\n");

  fs::unlink(output_filepath);

  ::_mergerfs_version(output_filepath);
  ::_uname(output_filepath);
  ::_lsb_release(output_filepath);
  ::_df(output_filepath);
  ::_lsblk(output_filepath);
  ::_mounts(output_filepath);
  ::_mount_point_stats(output_filepath);
  ::_mergerfs_settings(output_filepath);
  ::_fstab(output_filepath);
  ::_software_versions(output_filepath);
  ::_lshw(output_filepath);
  ::_journalctl(output_filepath);

  fmt::print("* Upload the following file to your"
             " GitHub ticket or put on https://pastebin.com"
             " when requesting support.\n* {}\n",
             output_filepath);

  return 0;
}