https://github.com/powerman/narada

Framework for ease deploy and support microservice projects
https://github.com/powerman/narada

backup configuration cron deploy deployment framework lock logging microservices migration mysql narada perl perl-module project-templates qmail runit

Last synced: 9 days ago
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Framework for ease deploy and support microservice projects

• Host: GitHub
• URL: https://github.com/powerman/narada
• Owner: powerman
• License: other
• Created: 2015-02-05T13:05:24.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2018-04-04T12:14:12.000Z (over 6 years ago)
• Last Synced: 2024-06-19T04:24:59.256Z (5 months ago)
• Topics: backup, configuration, cron, deploy, deployment, framework, lock, logging, microservices, migration, mysql, narada, perl, perl-module, project-templates, qmail, runit
• Language: Perl
• Homepage: https://metacpan.org/pod/Narada
• Size: 639 KB
• Stars: 7
• Watchers: 4
• Forks: 3
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • Changelog: Changes
  • License: LICENSE

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# NAME

Narada - framework for ease deploy and support microservice projects

# VERSION

This document describes Narada version v2.3.8

# SYNOPSIS

    #--- Create new project

    ~ $ narada-new my_proj

    ... New project will be created using template (from git repo).

    #--- Develop project as usually, until it's ready to run

    ~ $ cd my_proj

    ~/my_proj $

    ... Now you in project's source dir with git repo.

    ... You can develop this project in any way and language.

    #--- Make release and deploy it to check how it works

    ... NOTE: This operation is usually automated by script(s) provided

    ... by "project template" used while creating new project.

    ... Create file 0.1.0.migrate with instructions how to migrate between

    ... empty directory and version 0.1.0 of your project plus any related

    ... 0.1.0.{patch,tgz,etc.} files if you need them.

    ... Copy these files into .release/ subdirectory of directory where

    ... you want to deploy this version of project, for ex. in _live/.

    ~/my_proj $ cp 0.1.0.* _live/.release/

    ~/my_proj $ cd _live

    ~/my_proj/_live $ narada-install 0.1.0

    ... Now you in project's deploy directory, with config files, logs,

    ... running services, data files, etc. and you can check how it works.

    #--- Upgrade or downgrade project

    ... Repeat same steps to prepare 0.2.0.migrate and save into .release/.

    ~/my_proj/_live $ narada-install 0.2.0

    ... You can downgrade if something goes wrong.

    ~/my_proj/_live $ narada-install 0.1.0

    #--- You may need to update project's external configuration/data

    ~/my_proj/_live $ narada-setup-cron

    ~/my_proj/_live $ narada-setup-mysql

    ~/my_proj/_live $ narada-setup-qmail

    ~/my_proj/_live $ narada-start-services

    #--- You may need to backup this version and restore another one

    ~/my_proj/_live $ narada-backup

    ~/my_proj/_live $ cp .backup/full.tar .backup/full-0.2.0.tar

    ~/my_proj/_live $ narada-restore .backup/full-0.1.0.tar

    #--- You may need to lock project while manual maintenance

    ~/my_proj/_live $ narada-lock-exclusive

    [LOCKED] ~/my_proj/_live $

    ... Now all project applications will be blocked on next attempt

    ... to read/write any file or database, so you can safely change

    ... project files or databases, etc.

    [LOCKED] ~/my_proj/_live $ exit

    ~/my_proj/_live $

    ... Now project applications will be unblocked and continue to work.

    #--- Manage project

    ... View/monitor project's log.

    ~/my_proj/_live $ narada-viewlog

    ... Get console access to project's database.

    ~/my_proj/_live $ narada-mysql

    #--- Stop and uninstall this project.

    ... Cleanup related external configurations.

    ~/my_proj/_live $ narada-setup-cron --clean

    ~/my_proj/_live $ narada-setup-mysql --clean

    ~/my_proj/_live $ narada-setup-qmail --clean

    ... Kill all related background processes.

    ~/my_proj/_live $ narada-shutdown-services

    ~/my_proj/_live $ narada-bg-killall

    ... Then just remove it.

    ~/my_proj/_live $ cd ..

    ~/my_proj $ rm -rf _live/

# DESCRIPTION

Narada was designed for ease development, deploy and support for medium/big

server-side project or large amount of small projects (used in microservice

architecture). It's a framework which define **the 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 as long as your

project conform to Narada interface and work in \*NIX.

Typical example of project which wins a lot when managed by Narada is web

site backend or network service, which consists of several applications

(even written in different programming languages) with different entry

points (HTTP, RPC, cron, email), which all should have common runtime

environment, logs, etc.

In short, Narada dictates where your project should keep and how it should

work with: config files, logs, locks, temporary and persistent data files,

required external configuration for cron, qmail, databases. All of this is

called "Narada interface", and if your project conform to it then you can

also use a lot of handy command-line tools provided by Narada to deploy,

backup and manage your project.

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 (it

was designed that way to make it ease to conform to Narada interface even

in shell scripts).

To use Narada you'll also need to learn format of `.migrate` files used

to describe project's upgrade/downgrade operations (see

["SYNTAX" in App::migrate](https://metacpan.org/pod/App::migrate#SYNTAX)) and choose which "project template" to use for

your new project (for ex. see default template

[narada-base](https://github.com/powerman/narada-base); you can modify it

with plugins or develop your own template from scratch).

## Main features

- Templates and plugins for project source.

    You can choose one of existing templates when starting new project, and

    even modify some of them using plugins - or made your own templates or

    plugins if you often develop similar projects. Both templates and plugins

    are implemented by merging remote repositories, so if they will change

    after you've started your project you can easily update it by fetching and

    merging them again.

- You can continue using your favorite workflow.

    While [narada-new](https://metacpan.org/pod/narada-new) tool and existing project templates/plugins use Git,

    you may opt out and don't use them. This is only Narada tool which do

    something with your **project's source directory** (all other tools work

    only with **project's deploy directory**) and it's completely optional. You

    can create new project using Mercurial or even without using any VCS, and

    use any workflow you like. All you need is produce `.migrate` and related

    files as result of releasing every version of your project, including

    ephemeral development versions which you may release many times per day.

- Provide file/directory structure for deployed project.

    Some choices are already made for you: where and how to store project

    configuration, temporary and persistent data files, logs, locks, backups,

    current version number. This file/directory structure was designed to make

    it ease to use from any programming language (including shell scripts) and

    provide several valuable features like reliable upgrades and backups.

- Reliable project upgrade and downgrade.

    Narada use `.migrate` files to describe operations needed to upgrade and

    (required!) downgrade project. While usual development process you'll run

    these operations each time you wanna check how your changes work, i.e.

    this will happens dozens (if not hundreds) of times while you're

    developing next version, so both upgrade and downgrade operations are

    usually guaranteed to be well-tested before releasing each next version.

- Different project installations have different configurations.

    Changes in your local configuration won't be occasionally sent with next

    update to production server. And you won't have any issues because of

    config files added into your repo with project sources because in Narada

    projects config files exists only in **project's deploy directory**.

- Ease project setup after installation/update.

    Narada provide tools to update project's external setup (cron tasks, qmail

    handlers for incoming emails, MySQL scheme) according to current project's

    configuration.

- Reliable services.

    Run your FastCGI or RPC daemons with guaranteed restart after crash.

    Narada project may have own services, always running in background.

    By default we use [runit](http://smarden.org/runit/) for supervising

    project's services, but other similar supervisors like daemontools or s6

    also can be used.

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

    When your project consists of many applications/scripts or run many

    processes of same application it's important to have single common log for

    all of them. To implement this each Narada project usually run own log

    service. By default we use [socklog](http://smarden.org/socklog/)

    (syslog-compatible daemon) to receive logs from all project's applications

    and `svlogd` tool from [runit](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. NOTE: While Narada provide and use this lock file in it's own

    tools **it's your responsibility to always get shared lock on that lock

    file before doing read/write of any project's files or databases** - if you

    won't do this you'll break mentioned above consistency guarantee.

- Consistent and fast project backup.

    Narada interface include shared/exclusive project locking, which let us

    guarantee backup consistency between project files and databases.

    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/hourly backup!

- Backward compatibility.

    Whenever possible, projects created using previous Narada versions will be

    supported by latest Narada (but newly added tools may not work with such

    an old projects).

## Important changes since previous versions

### Narada 1.x

Narada 1 was created when Git and Mercurial wasn't exists yet, so it

doesn't use repository for project sources. Also it doesn't separate

project's source vs deploy directories and run project's applications in

directory with it sources - this was perfectly fine for projects developed

in script languages like Perl without using VCS. The `narada-new` tool

used to create Narada 1 projects is still available but it was renamed to

[narada-new-1](https://metacpan.org/pod/narada-new-1).

Also Narada 1 provide several tools used to generate, email/upload and

apply patches for project's directory - this was the way to both deploy

new version to server and distribute changes to other developers in team.

These tools has no use in current Narada, but they still exists for

compatibility with Narada 1 projects: [narada-diff](https://metacpan.org/pod/narada-diff), [narada-release](https://metacpan.org/pod/narada-release),

[narada-patch-remote](https://metacpan.org/pod/narada-patch-remote), [narada-patch-send](https://metacpan.org/pod/narada-patch-send), [narada-patch-pull](https://metacpan.org/pod/narada-patch-pull),

[narada-patch](https://metacpan.org/pod/narada-patch).

Files&directories structure also was changed since Narada 1.x, see

[Changes](https://metacpan.org/changes/distribution/Narada) in version

2.0.0 for more details.

This documentation describe current Narada, check documentation for

[latest Narada 1](https://metacpan.org/pod/release/POWERMAN/Narada-v1.4.5/lib/Narada.pm)

if you're still using Narada 1 projects.

# EXAMPLE

Create new project:

    ~ $ narada-new hello_world

    ... a lot of Git output skipped

    ~ $ cd hello_world/

    ~/hello_world $ ls -AF

    build*  deploy*  doc/  .git/  .gitignore  migrate  release*  t/

This is **project's source directory** initialized using default template.

It provide basic `migrate` files with all commands needed to create all

files/directories needed by every deployed Narada project plus few

scripts: `./release` for releasing new versions (both development

ephemeral versions and tagged final versions) and `./deploy` for

installing them into `_live/` subdirectory.

Cool, we already can release something!

    ~/hello_world $ ./release

    t/build/migrate.t .. 1/1 # Checking migrate

    t/build/migrate.t .. ok

    All tests successful.

    Files=1, Tests=1,  0 wallclock secs ( ... )

    Result: PASS

    ~/hello_world $ ls -AF

    build*  deploy*  doc/  .git/  .gitignore  migrate  release*  .release/

    t/  VERSION

    ~/hello_world $ ls -AF .release/

    0.0.0+b4ff31c.migrate  0.0.0+b4ff31c.patch

    ~/hello_world $ cat VERSION

    0.0.0+b4ff31c

As you see, your project get unique ephemeral version number in file

`VERSION` and this version was released as two files in `.release/`.

Now, let's deploy it!

    ~/hello_world $ ./deploy

    Loading .release/0.0.0+b4ff31c.migrate

    ... a lot of executed commands output skipped

    Migration to 0.0.0+b4ff31c completed

    ~/hello_world $ ls -AF

    build*  deploy*  doc/  .git/  .gitignore  _live/  migrate  release*

    .release/  t/  VERSION

    ~/hello_world $ ls -AF _live/

    .backup/  config/  doc/  .lock  .release/  t/  tmp/  var/  VERSION

The `_live/` is **project's deploy directory**. There are may be many of

them, even on same development machine in case you develop in several

branches and wanna have each branch deployed to separate directory, or

just wanna install simultaneously old and new versions of project and

compare how they work.

Okay, we get Narada files&directories structure in `_live/`, but it

doesn't have much use for now. Let's add something to our project.

    ~/hello_world $ cat >hello < #!/usr/bin/perl

    > print "Hello, World!\n";

    > EOF

    ~/hello_world $ chmod +x hello

    ~/hello_world $ git add hello

    ~/hello_world $ ./release && ./deploy

    t/build/migrate.t .. 1/1 # Checking migrate

    t/build/migrate.t .. ok

    All tests successful.

    Files=1, Tests=1,  0 wallclock secs ( ... )

    Result: PASS

    Loading .release/0.0.0+b4ff31c.dirty-1428492362.migrate

    Loading .release/0.0.0+b4ff31c.migrate

    Backuping to .backup/full-0.0.0+b4ff31c.tar

    ...

    Migration to 0.0.0 completed

    ...

    Migration to 0.0.0+b4ff31c.dirty-1428492362 completed

What just happens? New ephemeral version "0.0.0+b4ff31c.dirty-1428492362"

was released (it have such a name because we didn't committed our changes

to the repo yet); then previous version "0.0.0+b4ff31c" installed in

`_live/` was saved in the backup and downgraded to version "0.0.0" (which

is initial version meaning "empty directory"); then that empty directory

was upgraded to current version "0.0.0+b4ff31c.dirty-1428492362". Look:

    ~/hello_world $ cat VERSION

    0.0.0+b4ff31c.dirty-1428492362

    ~/hello_world $ ls -AF .release/

    0.0.0+b4ff31c.dirty-1428492362.migrate  0.0.0+b4ff31c.migrate

    0.0.0+b4ff31c.dirty-1428492362.patch    0.0.0+b4ff31c.patch

    ~/hello_world $ ls -AF _live/

    .backup/  config/  doc/  hello*  .lock  .release/  t/  tmp/  var/

    VERSION

    ~/hello_world $ cd _live/

    ~/hello_world/_live $ ./hello

    Hello, World!

    ~/hello_world/_live $ cd -

    ~/hello_world $

Next, let's start using some Narada features, like config files.

We'll also add migration operation to `migrate` file to create new config

file on upgrading to this version and remove it on downgrading from this

version.

    ~/hello_world $ echo 'add_config my_name Powerman' >> migrate

    ~/hello_world $ cat >hello < #!/usr/bin/perl

    > use Narada::Config qw( get_config_line );

    > printf "Hello, %s!\n", get_config_line('my_name');

    > EOF

    ~/hello_world $ ./release && ./deploy

    ...

    Loading .release/0.0.0+b4ff31c.dirty-1428493197.migrate

    Loading .release/0.0.0+b4ff31c.dirty-1428492362.migrate

    Backuping to .backup/full-0.0.0+b4ff31c.dirty-1428492362.tar

    ...

    Migration to 0.0.0 completed

    ...

    Migration to 0.0.0+b4ff31c.dirty-1428493197 completed

    ~/hello_world $ cd _live/

    ~/hello_world/_live $ ./hello

    Hello, Powerman!

In deploy directory we can safely modify config or data files - these

changes will affect only project deployed in this directory.

    ~/hello_world/_live $ ls -AF config/

    backup/  crontab/  log/  my_name  mysql/  qmail/

    ~/hello_world/_live $ echo Anonymous > config/my_name

    ~/hello_world/_live $ ./hello

    Hello, Anonymous!

    ~/hello_world/_live $ cd -

    ~/hello_world $

Now, let's release current version tagged with own version number.

    ~/hello_world $ git add migrate

    ~/hello_world $ git commit -m 'add hello'

    ~/hello_world $ ./release --minor

    t/build/migrate.t .. 1/1 # Checking migrate

    t/build/migrate.t .. ok

    All tests successful.

    Files=1, Tests=1,  0 wallclock secs ( ... )

    Result: PASS

    [master 8338faa] Release 0.1.0

     1 file changed, 4 insertions(+)

    ~/hello_world $ cat VERSION

    0.1.0

    ~/hello_world $ ls -AF .release/

    0.0.0+b4ff31c.dirty-1428492362.migrate  0.0.0+b4ff31c.migrate

    0.0.0+b4ff31c.dirty-1428492362.patch    0.0.0+b4ff31c.patch

    0.0.0+b4ff31c.dirty-1428493197.migrate  0.1.0.migrate

    0.0.0+b4ff31c.dirty-1428493197.patch    0.1.0.patch

    ~/hello_world $

And deploy it on server:

    ~/hello_world $ ssh localhost 'mkdir -p hello_project/.release'

    ~/hello_world $ scp .release/0.1.0.* localhost:hello_project/.release/

    0.1.0.migrate        100% 7105     6.9KB/s   6.9KB/s   00:00

    0.1.0.patch          100% 5223     5.1KB/s   6.9KB/s   00:00

    ~/hello_world $ ssh localhost

    ~ $ cd hello_project/

    ~/hello_project $ ls -AF

    .release/

    ~/hello_project $ ls -AF .release/

    0.1.0.migrate  0.1.0.patch

    ~/hello_project $ narada-install 0.1.0

    Loading .release/0.1.0.migrate

    ...

    Migration to 0.1.0 completed

    ~/hello_project $ ls -AF

    .backup/  config/  doc/  hello*  .lock  .release/  t/  tmp/  var/

    VERSION

    ~/hello_project $ ./hello

    Hello, Powerman!

    ~/hello_project $

Finally, let's cleanup and uninstall all projects.

Template used to create this project include some basic cron configuration

to make daily project backups. And these settings was already added to

your user's crontab while installing the project. So, before removing

project directories we should remove this cron setup.

    ~/hello_project $ narada-setup-cron --clean

    ~/hello_project $ cd ..

    ~ $ rm -rf hello_project/

    ~ $ exit

    ~/hello_world $ cd _live/

    ~/hello_world/_live $ narada-setup-cron --clean

    ~/hello_world/_live $ cd ../..

    ~ $ rm -rf hello_world/

# INTERFACE

The "Narada interface" is described here files&directories structure for

**project's deploy directory** and some conventions about how they should

be used. Your project must conform to this interface.

> For example, let's review part of Narada interface related to

> ["Consistent and fast project backup."](#consistent-and-fast-project-backup) feature.

>

> "Consistent" require using shared/exclusive file locking on file

> `.lock`. All Narada does is create that file while installing new

> project and acquire exclusive lock on it while executing [narada-backup](https://metacpan.org/pod/narada-backup).

> But to really have consistent backups **you** must acquire shared lock on

> that file when accessing any project files or database in any of your

> applications! In Perl scripts you can use helper module [Narada::Lock](https://metacpan.org/pod/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 MySQL 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 to `config/mysql/dump/incremental`.

>

> All of this will let [narada-backup](https://metacpan.org/pod/narada-backup) to hold exclusive lock (and thus

> freeze your project while backup) shortest possible time, complete safe

> part of backup task after releasing the lock, and use incremental backups

> to save both time and disk space.

## Directory types

There are two types of "root" directories in your project:

**source directory** and **deploy directory**.

The **project's source directory** isn't part of Narada interface.

Only tool which work with it is [narada-new](https://metacpan.org/pod/narada-new) (which helps you to create

new project), but you're not required to use it, and even if you use it no

Narada tools will touch your **project's source directory** after it will

be created.

The **project's deploy directory** is the one where all files&directories

defined by Narada interface should exists. Also **it's the directory where

you should run all Narada tools and your project's applications** - this is

required to allow them to find all Narada files&directories using paths 

relative to current directory.

It's ok to have many source directories (as repo clones for your team) and

to have many deploy directories (as different installations on same or

different computers) - for ex. it may be very useful to deploy different

versions from different Git branches to different deploy directories on

same development machine.

## Overview of deploy directory structure

Project templates often include typical directories like `doc/` or `t/`

but they isn't part of Narada interface and thus you're free to rename or

remove them if you like.

- `.release/`

    Contain `.migrate` and related files used to upgrade and downgrade

    project while migrating to another version.

- `.backup/`

    Contain project backups. You can create and manage them yourself, but they

    also will be automatically created before migrating to another version and

    may be automatically used when only way to downgrade project is restore

    previous version from backup. In general it's safe to remove backups when

    you like, but absence of some backups may make it impossible to downgrade

    to some previous version.

- `VERSION`

    Contain current project version. Required for upgrade and downgrade, and

    will be automatically updated after migration or restoring from backup.

    May be useful for your applications (read-only).

- `.lock*`

    Several lock files used mostly internally by Narada tools, except for

    the `.lock` file which should be shared-locked by all your applications

    while they read or write any project's files or databases.

- `config/`

    Project's configuration (both defined by Narada interface and custom

    settings of your project). May differ in different project's deploy

    directories. While it's possible to modify configuration in all deploy

    directories while project migration, usually most of config files modified

    either manually or by your applications in one deploy directory.

- `service/`

    Used to setup project's services (daemons) and run them using service

    supervisor (runit, daemontools, etc.). Most projects usually have just one

    (log) or a couple (log and fastcgi/http/rpc) services.

- `tmp/`

    Used for temporary data files. Contents of this directory won't be

    included in backups.

- `var/`

    Used for persistent data files.

## Deploy

In ["EXAMPLE"](#example) above you've seen scripts `./release`, `./deploy`, files

`migrate` and `VERSION`, directories `.release/` and `_live/` while

working with Narada, but all of them was in **project's source directory**

and isn't part of Narada interface! All of them was provided by used

project template, and different templates may implement these tasks in

different ways - read documentation for chosen project template. Also

you're free to modify these paths and scripts in any way - template

provide only starting point, but it's your project's sources and you have

freedom to do anything you like.

What is actually part of Narada interface is result of running these

`./release && ./deploy` scripts: file `.release/.migrate`

and optional related files (usually named `.release/.patch`

or `.release/.tgz`) in **project's deploy directory**.

No matter how you develop, build, compile, release and copy/upload new

version to deploy directory, the final result should be such file/files.

- `.release/.migrate`

    These files must contain upgrade and downgrade operations between version

    previous to `` and ``, but usually they also

    contain operations for all previous versions up to initial version "0.0.0"

    (meaning "empty directory").

    It's recommended to use [semantic versions](http://semver.org/), but

    except for predefined initial version "0.0.0" you're free to use for your

    project any version numbering scheme you like.

    Files&directories structure conforming to Narada interface must be created

    using upgrade operations in this file when describing upgrade from version

    "0.0.0".

    Narada uses [App::migrate](https://metacpan.org/pod/App::migrate) to implement project migrations, format of

    `.migrate` files is documented in ["SYNTAX" in App::migrate](https://metacpan.org/pod/App::migrate#SYNTAX).

    >     **When you need to convert some data in files or database when installing

    >     new version you should use** `.migrate` **file to run scripts which will

    >     do this.**

    >

    >     You should not try to do these data migrations automatically on first time

    >     new version of your project's application starts - both because this will

    >     make impossible to downgrade quickly and without losing data (if you'll

    >     provide script which does backward data conversion, of course) and you'll

    >     have to restore from backup instead, and because project migration may

    >     include many upgrades at once and your application as it was at one of

    >     intermediate versions wasn't get a chance to run at all.

## 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:

        ./.backup/*         to avoid recursively including old backups in new

        ./.lock*            to avoid unlocking while restoring from backup

        ./tmp/*             to conform to Narada interface and not include

                            temporary files in backups

- `config/mysql/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 `.backup/` or `var/mysql/`).

- `config/mysql/dump/empty`

    List of database tables (one per line) which records shouldn't be included in

    backup, only scheme.

- `config/mysql/dump/ignore`

    List of database tables (one per line) which shouldn't be included in

    backup at all (even scheme).

- `var/mysql/`

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

- `var/use/`

    Keeps current used/unused state recorded by last run of `narada-setup-*`

    and `narada-*-services` tools. It will be used by [narada-restore](https://metacpan.org/pod/narada-restore) to

    setup project after full restore.

- `.backup/full.tar`

- `.backup/incr.tar`

    Latest full and incremental backups. To force full backup next time just

    remove `.backup/full.tar`. See [narada-backup](https://metacpan.org/pod/narada-backup) for more details.

## 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`).

    It's recommended to use `syslog` type and run syslog-compatible log

    service for each project, because it's very hard to correctly implement

    concurrent writes to common log file.

    If set to `file` then each application in your project must open this

    file in append-only mode, avoid writing single log record using more than

    one write syscall (may happens because of buffered I/O), don't use NFS for

    `var/log/`… and you anyway may have some issues. One possible issue is

    performance: if you'll conform to Narada interface and acquire shared lock

    on `.lock` before writing each one line to log this may result in

    noticeable slowdown. Another possible issue happens if you avoid locking

    because of performance issue, but without locks it may be impossible to

    ensure log consistency in backups or reliably implement log rotation.

- `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`).

- `config/log/level`

    Current log level, should be one of these strings:

        ERR WARN NOTICE INFO DEBUG DUMP

- `var/log/`

    This directory contains project log files.

## 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/deploy/dir || exit;

    `narada-setup-cron` update system's cron using settings from these files.

## 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's deploy directory** instead of user's home directory

    (qmail's default behaviour).

- `var/qmail/*`

    Internally used by `narada-setup-qmail`.

## Database

Only MySQL supported at this time.

- `config/mysql/db`

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

    empty - Narada won't use database.

- `config/mysql/login`

- `config/mysql/pass`

    Login/pass for database.

- `config/mysql/host`

    Host name of database server. if this file doesn't exists or empty then

    usual UNIX socket will be used to connect to MySQL server.

- `config/mysql/port`

    TCP port of database server.

## Locking

- `.lock`

    This file should be shared-locked using flock(2) or [Narada::Lock](https://metacpan.org/pod/Narada::Lock) or

    [narada-lock](https://metacpan.org/pod/narada-lock) before accessing any project's files or database by usual

    applications, and exclusive-locked while project's backup, update or

    manual maintenance.

- `.lock.new`

    This file will be created before trying to acquire exclusive lock on

    `.lock`. All applications wanted to acquire shared lock on `.lock` must

    check before that is `.lock.new` exists and if yes then delay/avoid

    locking `.lock`. This is needed to guarantee exclusive lock will be

    acquired as soon as possible.

    After exclusive lock will be acquired and critical operations requiring it

    will be completed - `.lock.new` will be removed.

    If server will be rebooted while waiting for exclusive lock or in the

    middle of critical operations requiring it then file `.lock.new`

    won't be removed and project applications won't continue to work after

    server reboot until this file will be removed manually or another

    operation requiring exclusive lock will be started and successfully

    finished.

- `.lock.bg`

    Each project's background process (running as service, or started by cron,

    qmail, etc.) should acquire shared lock on this file. This can be easily

    done using [narada-bg](https://metacpan.org/pod/narada-bg) tool. This will make possible to reliably detect

    and kill all project's background processes while upgrade or downgrade

    using [narada-bg-killall](https://metacpan.org/pod/narada-bg-killall) tool.

## Services

There are several ways to start project's services: manually by running

[narada-start-services](https://metacpan.org/pod/narada-start-services) - this way they wasn't start automatically after

server reboot, try to start them every 1 minute from cron if they wasn't

running yet (usually using `config/crontab/service` but this file isn't

part of Narada interface) - this way it may took about 1 minute before

project services will be started after deploy or server reboot, run them

as one of system-wide service based on similar (runit/daemontools/s6/etc.)

supervisor - fastest and most reliable way but require root permissions to

add new system-wide service.

- `config/service/type`

    Type of used service supervisor. For now only supported type is `runit`.

- `.lock.service`

    This lock file is used by [narada-start-services](https://metacpan.org/pod/narada-start-services) to check is services

    already running.

# TOOLS

All tools (except [narada-new](https://metacpan.org/pod/narada-new)) must be executed in

**project's deploy directory**. Read man pages of these tools for details.

## Create new project

- [narada-new](https://metacpan.org/pod/narada-new)

## Deploy & uninstall

- [narada-install](https://metacpan.org/pod/narada-install)

- [narada-setup-cron](https://metacpan.org/pod/narada-setup-cron)

- [narada-setup-mysql](https://metacpan.org/pod/narada-setup-mysql)

- [narada-setup-qmail](https://metacpan.org/pod/narada-setup-qmail)

- [narada-shutdown-services](https://metacpan.org/pod/narada-shutdown-services)

- [narada-start-services](https://metacpan.org/pod/narada-start-services)

## Backup & restore

- [narada-backup](https://metacpan.org/pod/narada-backup)

- [narada-mysqldump](https://metacpan.org/pod/narada-mysqldump)

- [narada-restore](https://metacpan.org/pod/narada-restore)

## Background processes

- [narada-bg](https://metacpan.org/pod/narada-bg)

- [narada-bg-killall](https://metacpan.org/pod/narada-bg-killall)

- [narada-lock](https://metacpan.org/pod/narada-lock)

- [narada-lock-exclusive](https://metacpan.org/pod/narada-lock-exclusive)

## Misc tools

- [narada-viewlog](https://metacpan.org/pod/narada-viewlog)

- [narada-mysql](https://metacpan.org/pod/narada-mysql)

- [narada-emu](https://metacpan.org/pod/narada-emu)

## SSH tools

These tools make it easier to copy files between local and remote

project's deploy directories. If you're doing things in right way - you

won't need these tools.

- [narada-remote](https://metacpan.org/pod/narada-remote)

- [narada-upload](https://metacpan.org/pod/narada-upload)

- [narada-download](https://metacpan.org/pod/narada-download)

## Perl modules

- [Narada::Config](https://metacpan.org/pod/Narada::Config)

- [Narada::Lock](https://metacpan.org/pod/Narada::Lock)

- [Narada::Log](https://metacpan.org/pod/Narada::Log)

# SUPPORT

## Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker

at [https://github.com/powerman/Narada/issues](https://github.com/powerman/Narada/issues).

You will be notified automatically of any progress on your issue.

## Source Code

This is open source software. The code repository is available for

public review and contribution under the terms of the license.

Feel free to fork the repository and submit pull requests.

[https://github.com/powerman/Narada](https://github.com/powerman/Narada)

    git clone https://github.com/powerman/Narada.git

## Resources

- MetaCPAN Search

    [https://metacpan.org/search?q=Narada](https://metacpan.org/search?q=Narada)

- CPAN Ratings

    [http://cpanratings.perl.org/dist/Narada](http://cpanratings.perl.org/dist/Narada)

- AnnoCPAN: Annotated CPAN documentation

    [http://annocpan.org/dist/Narada](http://annocpan.org/dist/Narada)

- CPAN Testers Matrix

    [http://matrix.cpantesters.org/?dist=Narada](http://matrix.cpantesters.org/?dist=Narada)

- CPANTS: A CPAN Testing Service (Kwalitee)

    [http://cpants.cpanauthors.org/dist/Narada](http://cpants.cpanauthors.org/dist/Narada)

# AUTHOR

Alex Efros 

# CONTRIBUTORS

Nikita Savin 

Nick Levchenko 

# COPYRIGHT AND LICENSE

This software is Copyright (c) 2008- by Alex Efros .

This is free software, licensed under:

    The MIT (X11) License