reslog - Reverse-resolve IP in Apache log files

Description

reslog reverse-resolves IP in the Apache log files. These log files can then be analyzed by another program, like Analog. You can think of it as a replacement of Apache HostNameLookups directive, in the sense that it batch resolves the client IP once a day.

Caution

• Resolving takes long time. This is mainly caused by the look up: Network packets may be filtered by firewalls; DNS servers may not be correctly configured; may not be up working; may sit in slow network sections; may be old slow machines; may have traffic jam… etc. All these problems are beyond our control.

• If it stops in the middle of its execution, as when the user hits a Ctrl-Break, it may leave a temporary working file. The next time it runs, it stops when it sees that temporary working file at the first sight. Please process that file first. You can resolve it again, just like an ordinary log file.

• reslog needs temporary working space. Disk space is cheaper and is more available than memory. However, this means that it needs free temporary disk space about 2 times of the size of the uncompressed source log file (10 times if using memory). Please make sure you have that much free space.

• reslog does not support IPv6 yet.

• I suggest that you install File::MMagic instead of counting on the file executable. The internal magic file of File::MMagic works better than the file executable. reslog treats everything not gzip nor bzip2 compressed as plain text. When a compressed log file is wrongly recognized as an image, reslog treats it as plain text, reads directly from it, and fails. This does not hurt the source log files, but is still annoying.

System Requirement

1. Perl, version 5.8.0 or above. reslog uses 3-argument open() to duplicate file handles, which is only supported since 5.8.0. I have not successfully port this onto earlier versions yet. Please tell me if you made it.

   You can run perl -v to check your current Perl version. If you do not have Perl, or if you have an older version of Perl, you can download and install/upgrade it from the Perl website. For MS-Windows, you can download and install Strawberry Perl or ActivePerl.

2. Required Perl modules: None.

3. Optional Perl modules:

   • File::MMagic

     This is used to check the file type. If this is not available, reslog tries the file executable instead. If that is not available, too, reslog judges the file type by its name suffix (extension). In that case reslog fails when reading from STDIN. You can download and install File::MMagic from the CPAN archive, or install it with the CPAN shell:

     cpan File::MMagic
     

     or with the CPANPLUS shell:

     cpanp i File::MMagic
     

     For Debian/Ubuntu:

     sudo apt install libfile-mmagic-perl
     

     For Red Hat/Fedora/CentOS:

     sudo yum install perl-File-MMagic
     

     For FreeBSD:

     ports install p5-File-MMagic
     

     The alternative file.exe for MS-Windows can be obtained from the GnuWin32 home page. Be sure to save it as file.exe somewhere in your PATH.

   • Compress::Zlib

     This is used to support reading/writing the gzip compressed files. It is only needed when gzip compressed files are encountered. If it is not available, arclog tries the gzip executable instead. If that is not available, too, arclog fails. Compress::Zlib comes with Perl since version 5.9.3. If not, you can download and install it from the CPAN archive, or install it with the CPAN shell:

     cpan Compress::Zlib
     

     or with the CPANPLUS shell:

     cpanp i Compress::Zlib
     

     For Debian/Ubuntu:

     sudo apt install libio-compress-perl
     

     For Red Hat/Fedora/CentOS:

     sudo yum install perl-IO-Compress
     

     For FreeBSD:

     ports install p5-IO-Compress
     

     For ActivePerl:

     ppm install IO-Compress
     

     The alternative gzip.exe for MS-Windows can be obtained from the gzip website. Be sure to save it as gzip.exe somewhere in your PATH.

   • Compress::Bzip2 version 2 or above.

     This is used to support reading/writing the bzip2 compressed files. It is only needed when bzip2 compressed files are encountered. If it is not available, reslog tries the bzip2 executable instead. If that is not available, too, reslog fails. Notice that older versions before 2 does not work, since the file I/O compression was not implemented yet. You can download and install Compress::Bzip2 from the CPAN archive, or install it with the CPAN shell:

     cpan Compress::Bzip2
     

     or with the CPANPLUS shell:

     cpanp i Compress::Bzip2
     

     For Debian/Ubuntu:

     sudo apt install libcompress-bzip2-perl
     

     For Red Hat/Fedora/CentOS:

     sudo yum install perl-Compress-Bzip2
     

     For FreeBSD:

     ports install p5-Compress-Bzip2
     

     The alternative bzip2.exe for MS-Windows can be obtained from the bzip2 website. Be sure to save it as bzip2.exe somewhere in your PATH.

   • Term::ReadKey

     This is used to display the progress bar. The progress bar is a good visual feedback of what reslog is currently doing, but reslog is safe without it. You can download and install Term::ReadKey from the CPAN archive, or install it with the CPAN shell:

     cpan Term::ReadKey
     

     or with the CPANPLUS shell:

     cpanp i Term::ReadKey
     

     For Debian/Ubuntu:

     sudo apt install libterm-readkey-perl
     

     For Red Hat/Fedora/CentOS:

     sudo yum install perl-TermReadKey
     

     For FreeBSD:

     ports install p5-Term-ReadKey
     

     For ActivePerl:

     ppm install TermReadKey
     

Download

reslog is hosted is on…

• reslog project on GitHub

• reslog project on SourceForge

You can always download the newest version of reslog from…

• reslog download on SourceForge

• Tavern IMACAT’s FTP directory

imacat’s PGP public key is at…

• imacat’s PGP key at Tavern IMACAT’s

Install

If you are upgrading from reslog 3.10 or earlier, or if you are upgrading from reslog.pl 3.02 or earlier, please read the upgrade instruction later in this document.

Install with ExtUtils::MakeMaker

% perl Makefile.PL
% make
% make test
% make install

When running make install, make sure you have the privilege to write to the installation locations. This usually requires the root privilege.

For MS-Windows, since make is not universally available, Module::Build is preferred to ExtUtils::MakeMaker. See the instructions below.

Install with Module::Build

% perl Build.PL
% ./Build
% ./Build test
% ./Build install

When running ./Build install, make sure you have the privilege to write to the installation locations. This usually requires the root privilege.

If you want to install into another location, you can set the --prefix. For example, to install into your home when you are not root:

% perl Build.PL --prefix=/home/jessica

Refer to the documentation of Module::Build for more installation options (by running perldoc Module::Build).

Upgrade Instruction

Here are a few hints for people upgrading from 3.10 or earlier:

The Default Installation Location Is at /usr/bin

Also, the man page is at /usr/share/man/man1/reslog.1. This is to follow Perl’s standard convention, and to avoid breaking ExtUtils::MakeMaker with future versions.

When you run perl Makefile.PL or perl Build.PL, it hints a list of existing old files to be removed. Please delete them manually.

If you saved them in other places, you have to delete them yourself.

Also, if you have any scripts or cron jobs that are running reslog, remember to modify your script for the new reslog location. Of course, you can copy reslog to the original location. It still works.

Here are a few hints for people upgrading from 3.02 or earlier:

The Script Name is Changed from reslog.pl to reslog

This is obvious. If you have any scripts or cron jobs that are running reslog, remember to modify your script for the new name. Of course, you can rename reslog to reslog.pl. It still works.

The reason I changed the script and project name is that: A dot . in the project name is not valid everywhere. At least SourceForge don’t accept it. Besides, reslog is enough for a script name under UNIX. The .pl file name suffix/extension may be convenient on MS-Windows, but MS-Windows users won’t run it with explorer file name association anyway, and there is a pl2bat to convert reslog to reslog.bat, which would make more sense. The only disadvantage is that I was using UltraEdit, which depends on the file name extension for the syntax highlighting rules. I can manually set it anyway. I’m using gedit on Linux now. This is not a problem anymore.

You Need Perl 5.8.0 or Above

reslog now has threading to speed up resolving, which requires Perl’s ithreads threading module support that’s only available since 5.8.0. You can still disable threading if it causes troubles to you, but the code itself need it. If you are using a Perl before 5.8.0, please upgrade it. You can run perl -v to see your current Perl version.

The Default Keep Mode is Now delete

The documentation said the default keep mode is delete, but reslog actually did a restart. :p This is fixed. If you are running with the default keep mode, remember to fix it.

The Argument of --keep and --override Options Are Required Now

Support for omitting the --keep or --override arguments are removed. This helps to avoid confusion for the log file name and the option arguments.

Specifying One STDIN No Longer Trigger Everything to STDOUT

When resolving multiple files, STDIN can output to STDOUT now, with other files output to where they should be. Specifying one STDIN no longer writes everything to STDOUT. If you want to write everything to STDOUT, be sure to add the --stdout option.

Options

./reslog [options] [logfile…]
./reslog [-h|-v]

• logfile

  The log file to be resolved. You can specify multiple log files. If not specified, it reads from STDIN and outputs to STDOUT. You can also specify - to read from STDIN. Result of STDIN goes to STDOUT. gzip or bzip2 compressed files are supported.

• -k, --keep mode

  What to keep in the source file. The following modes are supported:

  • a, all

    Keep the source file after records are archived.

  • r, restart

    Restart the source file after records are resolved.

  • d, delete

    Delete the source file after records are resolved. This is the default.

• -o, --override mode

  What to do with the existing resolved files. The following modes are supported:

  • o, overwrite

    Overwrite existing target files.

  • a, append

    Append the records to existing target files.

  • f, fail

    Stop processing whenever a target file exists, to prevent destroying existing files by accident. This is the default.

• -s, --suffix suf

  The suffix to be appended to the output file. If not specified, the default is .resolved.

• -t, --trim-suffix suf

  The suffix to be trimmed from the input file name before appending the above suffix. Default is none. If you are running several log file filters, this can help you trim the suffix of the previous one.

• -n, --num-threads num

  Number of threads to run simultaneously. The default is 10. Use 0 to disable threading. Your system must support threading itself. This option has no effect for systems that do not support threading.

• -c, --stdout

  Output the result to STDOUT.

• -d, --debug

  Show the detailed debugging messages. More -d to be more detailed.

• -q, --quiet

  Hush! Only yell on error.

• -h, --help

  Display the help message and exit.

• -v, --version

  Output version information and exit.

Documentation

Type perldoc reslog to read the reslog manual.

News, Changes and Updates

Refer to the Changes for changes, bug fixes, updates, new functions, etc.

Support

The reslog project is hosted on GitHub. Address your issues on the GitHub issue tracker https://github.com/imacat/reslog/issues.

Thanks

• Thanks to SourceForge for hosting the project.

License

Copyright (C) 2000-2021 imacat.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

imacat ^_*'
2007/12/4
imacat@mail.imacat.idv.tw
https://www.imacat.idv.tw