Alex Efros > Narada-1.3.6 > Narada

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Module Version: v1.3.6   Source   Latest Release: Narada-1.3.10

NAME ^

Narada - framework for ease development/deploy/support for medium/big projects

VERSION ^

This document describes Narada version 1.3.6

SYNOPSIS ^

    # Run narada-* commands.
    # In perl scripts either use Narada::* modules or manually
    # conform Narada interface.
    # In non-perl applications just conform Narada interface.

DESCRIPTION ^

Narada designed for ease development, deploy and support for medium and big projects. It's main goal is to restrict you with one way to manage your project (which doesn't really depend on your project's nature), and doesn't restrict your project's implementation in any way. With Narada you can create any projects using any programming languages - while your projects conform Narada interface (and developed in *NIX - Windows not supported).

There are few helper Narada::* modules for perl which helps you to conform Narada interface in your perl modules/scripts; for other languages you may want to create similar helpers, but this isn't required - Narada interface is simple and can be easily conformed without using special helpers.

Typical example of project which wins a lot when managed by Narada is web or network service, which consists of several scripts (which all should have common runtime environment, logs, etc.) with different entry points (cgi, rpc, cron, email).

Main Features

Create files and directory structure for new project.

Project doesn't required to use database, all configuration/logs/etc. are stored in files.

Different project installations have different configuration.

Changes in your local configuration won't be occasionally sent with next update to production server.

Ease project setup after installation/update.

Narada provide helpers to update project environment (cron tasks, qmail handlers, mysql scheme) according to current project's configuration.

Reliable services.

Run your FastCGI or RPC daemons with guaranteed restart after crash. By default we use tools from http://smarden.org/runit/ for supervising project's services, but other similar supervisors like daemontools also can be used.

All project's applications have common log(s).

By default we use http://smarden.org/socklog2/ (syslog-compatible daemon) to receive logs from project's applications and svlogd tool from http://smarden.org/runit/ to manage logs (rotate, filter, group records in separate files, etc.).

All project's applications have common lock.

This guarantee live project's consistency while backup, update or manual maintenance.

Basic support for team development and versioning project.

Narada make it easier to release and deploy updates on server. Team members may merge these updates with their working copy of project. Each update consists of several .patch, .sh, .sql and .tgz files, and can be easily reviewed/corrected before releasing.

This feature doesn't meant as replacement for VCS - you can use or don't use any VCS with Narada: VCS is versioning your files, while Narada is versioning your project. But in simple cases (small team, everyone works on mostly isolated tasks) this feature can replace needs in VCS (even then some team members still may use VCS locally, for example to use branches).

Consistent and fast project backup.

Narada interface include shared/exclusive project locking, which let us guarantee backup consistency between project files and database.

Narada backup tool support incremental backups both for files and database, which makes it possible to backup most projects in few seconds - your website visitors won't even notice your daily backup!

INTERFACE ^

Narada, as a framework, provide you with some interface (mostly it's just conventions about some files and directories), and you MUST conform to that interface of things will break.

For example, let's review interfaces related to "Consistent and fast project backup" feature.

"Consistent" require using shared/exclusive file locking on file var/.lock. All Narada does is create that file when generate new project and acquire exclusive lock on it while executing narada-backup. But to really have consistent backups you must acquire shared lock on that file while modifying any project files or database in any of your scripts! In perl scripts you can use helper module Narada::Lock, and it's not a big deal to manually use flock(2) in any other language. If you fail to do this, you backups won't be guaranteed to be consistent anymore!

"Fast" consists of two parts: files and database. To backup project files fast you should keep large junk files according to Narada's interface - in directories listed in config/backup/exclude, for ex. in tmp/. To backup database fast you should try hard to store large amount of data in append-only tables with auto_increment primary key, and add names of these tables in config/db/dump/incremental.

New project created in separate directory using narada-new. This directory become "project root" directory (also called "project dir"). All project applications and narada-* commands must be executed in this directory (so they will be able to find all project files/dirs using relative path).

These directories will be created in project root:

config/

Project's configuration (both predefined by Narada and custom settings related to your project). May differ between different installations of this project (by default project updates include only new and deleted settings, but not changed settings).

doc/

Contain ChangeLog. Put your documentation here.

service/

This directory should be used to setup project's services (daemons) and run them using service supervisor (runit, daemontools, etc.).

t/

Put your tests here.

tmp/

Files stored in this directory won't be included in backups and updates.

var/

Variable files required for Narada and your project. Will be included in backup, but not in updates.

Team development and versioning project

config/version

Project name and version in flexible format: one string, which must contain at least one digit, and doesn't contain whitespace or /). Example: "App-0.1.000" (without quotes).

narada-new will create this file with content "PROJECTNAME-0.0.000" where PROJECTNAME is name of project root directory.

Last number in this string will be automatically incremented by narada-release unless this file was manually modified since previous narada-release run.

config/version.*

Name and version of installed addons.

config/patch/send/*

Each file contain one line with email of team member, who wanna receive emails with project updates. Used by narada-patch-send. File names are not important, but usually they match team member's $USER.

If $NARADA_USER is set, then narada-new will put it value into config/patch/send/$USER.

config/patch/exclude

PCRE regex (one per line) for files/dirs which shouldn't be included in project update. config/ directory handled in special way and shouldn't be listed in this file.

doc/ChangeLog

Project's change log, in standard format. narada-release will ask you to enter changes using $EDITOR and then automatically insert/update line with date/version.

doc/ChangeLog.*

Change logs of installed addons.

var/patch/

Contains all project updates (patches). narada-diff will create new update candidate in this directory for manual review; narada-release will turn candidate into released update; narada-patch will apply updates found this this directory to project; etc.

var/patch/PENDING.*

You should put into these files custom sql/sh commands which should be included with next update.

var/patch/ChangeLog

Symlink to doc/ChangeLog for convenience.

var/patch/.mc.menu

Shortcuts for convenience (to run narada-* in project root without leaving var/patch/ where you now reviewing current patch).

var/patch/.prev/

Contains "master" copy of current project's version (VCS keeps it in .git or .hg), for internal use by narada-diff. Should never be modified manually!

var/patch/*/

Contains "addon" patches.

Backup

config/backup/exclude

Shell patterns (one per line) for files/dirs which shouldn't be included in backup. Must contain at least these lines:

    ./var/.lock.new     to avoid project in locked state after restore
                        from backup
    ./var/backup/*      to avoid recursively including old backups in new
    ./var/patch/.prev/* harmless, but it always can be restored by
                        applying all released updates on empty project
config/db/dump/incremental

List of database tables (one per line) which can be dumped incrementally (according to their auto_increment primary key field). narada-backup will dump only new records in these tables (dumps for older records will be available in existing files in var/backup/ or var/sql/).

config/db/dump/empty

List of database tables (one per line) which records shouldn't be included in backup, only scheme.

config/db/dump/ignore

List of database tables (one per line) which shouldn't be included in backup at all (even scheme).

var/sql/

Contains files with last database dump (usually made while last backup).

var/backup/

Contains helper files required for incremental backups and backups itself.

Logging

config/log/type

Define type of logging: syslog (default if this file not exists) or file. If set to syslog then config/log/output should contain path to syslog's unix socket (like var/log.sock or /dev/log). narada-new initialize this file with syslog value.

config/log/output

File name where project applications should write their logs: either unix socket (to syslog-compatible daemon) or usual file (or /dev/stdout). narada-new initialize this file with var/log.sock value.

config/log/level

Current log level, should be one of these strings:

    ERR WARN NOTICE INFO DEBUG DUMP

narada-new set it to DEBUG.

service/log/

Syslog-compatible service listening to var/log.sock and saving logs into var/log/. Can be switched off only if you doesn't write logs to var/log.sock.

var/log/

This directory contains project log files.

Services

service/*/

Services (daemons) of this project. Most projects have just one (log) or two (log and fastcgi) services.

Cron Tasks

config/crontab

Settings for project's cron tasks, in crontab format.

When these settings will be installed to system's cron, each command will be automatically prefixed by:

    cd /path/to/project/root || exit;

narada-new create it with single task - run service supervisor and thus start all project services in service/*/. This way project services will be restarted even after OS reboot.

narada-setup-cron update system's cron using settings from this file.

Processing Incoming Emails

Only qmail supported at this time.

config/qmail/*

Files with qmail configuration (in .qmail format). Commands listed in these files (lines beginning with |) will be executed in project root directory, instead of user's home directory (qmail's default behavour).

var/qmail/*

Internally used by narada-setup-qmail.

Database

Only MySQL supported at this time.

config/db/db

Contains one line - name of MySQL database. If this file doesn't exists or empty - Narada won't use database.

config/db/login
config/db/pass

Login/pass for database.

config/db/host

Host name of database server. if this file doesn't exists or empty unix socket will be used to connect to MySQL server.

config/db/port

TCP port of database server.

Locking

var/.lock

This file should be shared-locked using flock(2) or Narada::Lock or narada-lock before modifying any project's files or database by usual applications, and exclusive-locked while project's backup, update or manual maintenance.

var/.lock.new

This file created before trying to exclusive-lock var/.lock. All applications wanted to shared-lock var/.lock should first check is var/.lock.new exists and if yes then delay/avoid locking var/.lock. After exclusive lock will be acquired var/.lock.new will be removed. This is needed to guarantee exclusive lock will be acquired as soon as possible.

If server will be rebooted while waiting for exclusive lock then file var/.lock.new won't be removed and project applications won't continue working after booting server until this file will be removed manually.

Tools ^

All tools (except narada-new) must be executed in project root. Read man pages of these tools for details.

    narada-new
    narada-setup-cron
    narada-setup-mysql
    narada-setup-qmail
    narada-shutdown-services

    narada-backup
    narada-mysqldump

    narada-diff
    narada-release
    narada-patch-remote
    narada-patch-send
    narada-patch-pull
    narada-patch

    narada-remote
    narada-upload
    narada-download

    narada-viewlog
    narada-mysql
    narada-emu

    narada-lock
    narada-lock-exclusive

CONFIGURATION AND ENVIRONMENT ^

$NARADA_USER optionally can be set to user's email. If set, it will be used by narada-new to initialize config/patch/send/$USER; by narada-patch-send to avoid sending email to yourself; by narada-release when adding header lines into doc/ChangeLog.

DEPENDENCIES ^

None.

INCOMPATIBILITIES ^

None reported.

BUGS AND LIMITATIONS ^

No bugs have been reported.

Please report any bugs or feature requests to bug-narada@rt.cpan.org, or through the web interface at http://rt.cpan.org.

AUTHOR ^

Alex Efros <powerman@cpan.org>

CONTRIBUTORS ^

Nick Levchenko <project129@yandex.ru>

LICENSE AND COPYRIGHT ^

Copyright (c) 2008-2013 Alex Efros <powerman@cpan.org>. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

DISCLAIMER OF WARRANTY ^

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

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