Narada - framework for ease development/deploy/support for medium/big projects
This document describes Narada version 1.2.2
# Run narada-* commands. # In perl scripts either use Narada::* modules or manually # conform Narada interface. # In non-perl applications just conform Narada interface.
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).
Project doesn't required to use database, all configuration/logs/etc. are stored in files.
Changes in your local configuration won't be occasionally sent with next update to production server.
Narada provide helpers to update project environment (cron tasks, qmail handlers, mysql scheme) according to current project's configuration.
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.
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.).
This guarantee live project's consistency while backup, update or manual maintenance.
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).
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!
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
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:
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).
ChangeLog. Put your documentation here.
This directory should be used to setup project's services (daemons) and run them using service supervisor (runit, daemontools, etc.).
Put your tests here.
Files stored in this directory won't be included in backups and updates.
Variable files required for Narada and your project. Will be included in backup, but not in updates.
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
Name and version of installed addons.
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
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.
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.
Change logs of installed addons.
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.
You should put into these files custom sql/sh commands which should be included with next update.
doc/ChangeLog for convenience.
Shortcuts for convenience (to run
narada-* in project root without leaving
var/patch/ where you now reviewing current patch).
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!
Contains "addon" patches.
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
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
List of database tables (one per line) which records shouldn't be included in backup, only scheme.
List of database tables (one per line) which shouldn't be included in backup at all (even scheme).
Contains files with last database dump (usually made while last backup).
Contains helper files required for incremental backups and backups itself.
Define type of logging:
syslog (default if this file not exists) or
file. If set to
config/log/output should contain path to syslog's unix socket (like
narada-new initialize this file with
File name where project applications should write their logs: either unix socket (to syslog-compatible daemon) or usual file (or
narada-new initialize this file with
Current log level, should be one of these strings:
ERR WARN NOTICE INFO DEBUG DUMP
narada-new set it to
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
This directory contains project log files.
Services (daemons) of this project. Most projects have just one (
log) or two (
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.
Only qmail supported at this time.
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).
Internally used by
Only MySQL supported at this time.
Contains one line - name of MySQL database. If this file doesn't exists or empty - Narada won't use database.
Login/pass for database.
Host name of database server. if this file doesn't exists or empty unix socket will be used to connect to MySQL server.
TCP port of database server.
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.
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.
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
$NARADA_USER optionally can be set to user's email. If set, it will be used by
narada-new to initialize
narada-patch-send to avoid sending email to yourself; by
narada-release when adding header lines into
No bugs have been reported.
Please report any bugs or feature requests to
email@example.com, or through the web interface at http://rt.cpan.org.
Copyright (c) 2008-2013 Alex Efros
<powerman.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.
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