SparrowHub Plugins Request

A quick search at github on something like Perl/Bash scripts gives me a lot of results.

As developers we more think about modules and libraries when talk about software reuse. But in our day-to-day life scripts still take a vital part. Scripts like little, but useful commands to get our job done. This is why people from many programming languages/environments tend to create a places for such a tools called repositories, so other could easily find, install and run scripts or utilities. To list a few:

Well. A SparrowHub is a attempt to make a such effort in Perl communities to create a repository of useful automation scripts. Sparrow is Perl friendly in many ways:

  • it is written on Perl
  • it gets installed as CPAN module
  • it respects carton/cpanfile dependency management for your scripts
  • it supports Config::General format for script configuration ( among JSON, YAML and command line parameters )

Well let me now turn to the essential point of my post.

I know there are a plenty of cool software written by Perl community we know as CPAN, and many, many Perl modules get shipped with some useful scripts, even more some module's are only public interface - some command line scripts. So why not to upload such a script into a repository so other could use it? I know not all the cases are good fit, but let me outline some criteria if your script could be a good candidate to be uploaded as sparrow plugin:

  • you have some command line tools based on existed Perl/CPAN/Bash scripts and want to share it somehow with others or even keep it for yourself so to repeat script installation / execution process in the same way every time you setup a new server.

  • script takes a lot of input parameters or parameters with the structure is hard to be expressed in command line manner ( Hashes, Lists, Groups, so on ).

  • you need to add some middle-ware steps to your script logic , but don't want to add this into scripts source code.

  • you need to build a more complex tool based on your low level script/utility.

  • script possibly gets run often and / or on multiple servers.

  • script requires some extra checks so one could run it safely.

  • script is a generic tool acting differently depending on input parameters.

So if this sounds like about your scripts, you may start playing with SparrowHub. After all it's just distribution platform, having minimal impact at your script code:

  • You write/already have a script ( plus some dependencies software like CPAN module )
  • You upload script / or script based tool to SparrowHub as sparrow plugin
  • Others may find, install and run your script ( via SparrowHub ).

If this sounds interesting there are simple `how to contribute' steps:

  • Get registered at SparrowHub
  • Convert your script into sparrow plugin
  • Upload new sparrow plugin

In case you still have a questions or need help on converting your scripts into sparrow plugin, please:

  • Post an issue at sparrow/issues
  • Or ask your question at [SparrowHub Google Group](!forum/

Finally, if you feel like you have no time to dive into new things and study docs, but you are still interested in the subject, just let me know ( creating an issue at sparrow/github ) about script you wish add sparrowhub to and I will try to do it soon.


Alexey Melezhik

Monitoring minion workers/tasks using Sparrow

Hi! This is small post concerning sparrow plugin to monitor minion workers. I had some post on this recently, but now I have made some improvements at existed plugin, so I am writing a new one ...

On my production server I use Minion to send emails to my clients. For some reasons there are faults on executing minion tasks or even minion workers get stopped sometimes for reasons unknown. As sending emails is a vital part of the service registration system I need to know if everything goes bad with my email system. Here is minon-check sparrow plugin to risqué.

Install sparrow

$ cpanm Sparrow

Install sparrow plugin

$ sparrow index update # get latest plugins index from Sparrowhub
$ sparrow plg install minion-check # install plugin

Set plugin up

$ sparrow project create webapp # create a projects to hold web applications tasks
$ sparrow task add webapp minion-health minion-check # this is 
# minion health task which is "tied" to minion-check plugin

$ EDITOR=nano  sparrow task ini webapp minion-health # set task parameters. 
# on my server this will be:

# I use carton install, so:
command = cd /path/to/your/mojo/app && carton exec ./ minion

# sets worker footprint to lookup at processes list
worker_cmd = minion worker

A few comments on plugin setup here:

  • A command parameter define a system command to handle your minion jobs/tasks , An is Mojolicious application to run my web application, so I set my minion command as mojolicious command.

  • A worker_cmd parameter is just a string to look up inside a process list, to identify that minion worker is alive. A simple stings minion worker works for me.

Let's run a task and see the output:

$ sparrow task run webapp minion-health


/modules/check-worker/ started

look up {{{minion worker}}} at proccess list ...
web-app       2748  0.3  3.4 202704 35216 pts/0    S    23:17   0:00 perl ./ minion worker -m production -I 15 -j 2
ok      scenario succeeded
ok      output match 'done'

/modules/last-task/ started

ok      scenario succeeded
ok      output match /Q=(1|0)/

/ started

no failed tasks found
ok      0 failed jobs found

So what sparrow plugin minion-check does?

  • check if your minion worker(s) is running.

  • check if you have no tasks marked as FAILED for the given period of time. ( I do not set it up explicitly here, but for default it uses 10 minutes interval , for details follow minion-check documentation ).

Finally I setup cron job to run a sparrow plugin every 10 minutes:

$ sparrow task run webapp minion-health --cron

A --cron flag makes sparrow client silent unless any errors happen during execution.


Alexey Melezhik

Sparrowdo automation. Part 6. Sparrowdo modules - getting a bigger things using light primitives.

This is what have been seen before:

Well, while keep writing a sparrowdo tutorial the tool keep growing too. Let me introduce something new and excited about sparrowdo automation - how one can easily create a higher level entities using so called sparrowdo modules.

Sparrowdo modules ...

So far we have talked about some sparrowdo primitives. They are light, they are small and they relate to a small specific tasks, under the hood they are just sparrow plugins with parameters - sparrowdo tasks.

Well, here is the list to recall a few:

  • System packages - package-generic plugin
  • CPAN packages - cpan-package plugin
  • Users and groups - are user and group plugins
  • Linux Services are represented by service plugin
  • And more and more and more ...

And so on, you can see all of them here, on sparrowhub site - Most of sparrow plugins are just black boxes to solve a specific task. More or less plugins are just primitives.

Take a look at chef resources or ansible modules - they are probably of the same nature.

Now let's me introduce a sparrowdo module - a container for sparrow plugins.

Consider a quite common task. Installing Nginx web server. Having looked at sparrow toolkit we have all necessary bricks to "build" a running Nginx server:

  • Package-generic plugin to install nginx package
  • Service plugin to enable and run nginx service

Let's write code then:

use v6;

unit module Sparrowdo::Nginx;

use Sparrowdo;

our sub tasks (%args) {

  task_run  %(
    task => 'install nginx',
    plugin => 'package-generic',
    parameters => %( list => 'nginx' )

  task_run  %(
    task => 'enable nginx',
    plugin => 'service',
    parameters => %( service => 'nginx', action => 'enable' )

  task_run  %(
    task => 'start nginx',
    plugin => 'service',
    parameters => %( service => 'nginx', action => 'start' )


Ok. The code is quite simple, I just want to add some vital comments here.

  • Sparrowdo modules are plain Perl6 modules.

  • You need to load Sparrowdo module to export some sparrowdo API functions, like task_run or others.

  • You have to define at least a tasks(%args) function gets called when someone else use your modules, see how later

  • You optionally may handle some arguments get passed into your module, see tasks function signature.

  • And finally sparrowdo module is just a container for some sparrowdo tasks get called sequentially .

Ok. Now lets use our new sparrowdo module.

First step we need to ensure that module installed at the server where from we are going to run a sparrowdo tasks:

$ panda install Sparrowdo::Nginx

Ok when we are ready with module install we have two ways here.

  1. running module as is

  2. using module inside sparrowdo scenario.

Running module as is

This is the simplest way. This is very similar to running ansible modules:

sparrowdo --host= --module_run=Nginx

install nginx server

Running module via sparrowfile

Of course one can just use sparrowdo module using sparrowdo API

$ cat sparrowfile

run_module 'Nginx';

Sparrowdo uses a convention about modules names, it cut a Sparrowdo:: prefix from module name when run it via run_module function. So the rule is simple:

| Module Perl6 Name | Run_module $name parameter |
| Sparrow::Foo::Bar | 'Foo::Bar'                 |

A current version of Sparrowdo::Nginx ignore an arguments, one day it would be possible to call 'Nginx' module with parameters:

run_module 'Nginx', %( port => 81 );

Little helpers for developers life

Sparrowdo provides some essentials helpers to simplify some developers tasks.

Guessing a target OS

It's very usual when we need to know a target server OS name to make a right decision about server configuration. Let me show you. Recall Nginx module, for centos we need install a repository so nginx package is not here by default:

our sub tasks (%args) {

  if target_os() ~~ m/centos/ {

    task_run  %(
      task => 'install epel-release',
      plugin => 'package-generic',
      parameters => %( list => 'epel-release' )


Passing a sparrowdo command line parameters

Remember a post on installing CPAN packages on the servers with http proxy restrictions?

Consider this sparrwodo module to install CPAN modules:

use v6;

unit module Sparrowdo::CpanInstall;

use Sparrowdo;

our sub tasks (%args) {

  task_run  %(
    task => 'install cpan modules',
    plugin => 'cpan-package',
    parameters => %( 
      list => %args<list>,
      http_proxy => input_params('HttpProxy'), 
      https_proxy => input_params('HttpsProxy'), 


And sparrowfile:

module_run 'CpanInstall' %(
  list => 'DBI Moose Mojolicious'

And finally sparrowdo scenario run:

$ sparrwodo --host=<$some-host> --http_proxy=<$http_proxy>  --https_proxy=<$https_proxy>

An input_params($param_name) function will pass all the sparrowdo client parameters back to Sparrowdo::CpanInstall module.


Sparrowdo modules are high level members of sparrowdo echo system. What is good they are just Perl6 modules. Anybody who codes at Perl6 could easily start a new ones ( a basic knowledge of existed sparrow plugins is required though ).

Here is a short list of my ones:

Will be happy to see a new members of Sparrowdo::* family at Perl6 modules repository.

Regards and have a good weekend.

Alexey Melezhik

Outthentic does not rely on Test::More any more.

Finally I decided not to use Test::More and Perl Test-Harness in Outthentic anymore.

These are the great tools proven in many many testing projects. But Outthentic tends to be more general purpose framework to run ANY scripts, rather than being a test framework only. Some testing facilitates are still here, but they poorly use a Test::More/Test-Harness entities, so I decided to rewrite story runner to get an asserts execution results in free style - so no TAP indeed is required.

$ cat 

print "hello from perl";

$ cat story.check 
hello from perl

$ strun 

/ started

hello from perl
OK  scenario succeeded
OK  output match 'hello from perl'

Such a changes might result in potential breakage for some sparrow plugins but I will fix it soon.

-- Regards

Alexey Melezhik

Sparrowdo automation. Part 5. Managing services and processes.


This time I want to tell you how to manage services and processes using sparrowdo.

Before this post a following list of topics was written by me:

As services are highly coupled with processes we will investigate them in one post.

Let's have an nginx web server gets installed on your system:

$ cat sparrowfile

use v6;

use Sparrowdo;

task_run  %(
  task => 'install nginx server',
  plugin => 'package-generic',
  parameters => %( list => 'nginx' )

We talked about package-generic plugin at this post. We use this plugin to install system packages.

install nginx server

Ok. This is very logical now having installed an nginx to make it "bootable", so next reboot of our system will pickup an nginx and make it sure it runs too. Some people call this autoload:

$ cat sparrowfile

use v6;

use Sparrowdo;

task_run %(
  task => 'enable nginx service',
  plugin => 'service',
  parameters => %( action => 'enable', service => 'nginx' )

task_run %(
  task => 'start nginx service',
  plugin => 'service',
  parameters => %( action => 'start', service => 'nginx' )


A service plugin makes it possible to enable and disabling Linux services, as well as starting and stopping them. It's very simple yet useful plugin for those who want to automate Linux services on target hosts.

At example here we not only make it nginx autoloadable enabling it, but also make it sure it starts. So good so far.

Well time goes and we need to ensure that nginx server is running. There are more than one way to do this.

The simplest one is to look up in a processes tree a process related to nginx master. This is what I usually do first when troubleshoot nginx server issues.

$ cat sparrowfile

use v6;

use Sparrowdo;

task_run  %(
  task => 'check my nginx master process',
  plugin => 'proc-validate',
  parameters => %(
    pid_file => '/var/run/',
    footprint => 'nginx.*master'


A proc-validate plugin takes 2 parameters at input. The first one is the path to file where PID is written, and the second optional one - Perl regular expression to identify a process at process tree. Even providing only the first parameter is enough but I also set a footprint to make my example more explanatory.


We've learned how to manage Linux services with the help of sparrowdo. It's easy and it makes your routine tasks automated. And if you want to add some "audit" to your running services, which of course sounds reasonable for maintainers jobs the easiest way to start with is using simple proc-validate plugin.

See you soon at our next topic.

Have a fun in coding and automation.

-- Alexey Melezhik