Tag: php

Linux (Ubuntu 16.04), PHP and MS SQL

In the many years I’ve been using the traditional LAMP stack, I’ve successfully managed to avoid having anything to do with MS SQL server. Until 2016. This year I’ve had to work quiet a bit with it – administration, backups and, now, scripted queries from Linux with PHP.

I suspect I’m (a) lucky I haven’t had to do this before now; and (b) that Azure seems to have pushed Microsoft into greater Linux based support for MS SQL. The evidence? This open source Mircosoft repository with a MS SQL PHP binary driver for Linux released just a few months ago.

NB: installing the Microsoft PHP driver is different to installing the Microsoft ODBC driver for SQL Server on Linux. These may even be incompatible.

For me, I just took a standard Ubuntu 16.04 install (64bit obviously) with PHP 7.0 and downloaded the latest MS PHP SQL extension (for me, at time of writing, this was 4.0.6. When you untar the Ubuntu16.tar file, copy the .so files to /usr/lib/php/20151012/ and then create a /etc/php/7.0/mods-available/msphpsql.ini file with contents:

extension=php_pdo_sqlsrv_7_nts.so
extension=php_sqlsrv_7_nts.so

Note that the tar also contains two ‘ts’ versions of these files. Trying to use those resulted in errors. Link this for Apache2 / CLI as required. E.g. for PHP CLI:

cd /etc/php/7.0/cli/conf.d/
ln -s ../../mods-available/msphpsql.ini 20-msphpsql.ini

You can confirm it’s working via:

$ php -i | grep sqlsrv
Registered PHP Streams => https, ftps, compress.zlib, php, file, glob, data, http, ftp, sqlsrv, phar
PDO drivers => sqlsrv
pdo_sqlsrv
pdo_sqlsrv support => enabled
pdo_sqlsrv.client_buffer_max_kb_size => 10240 => 10240
pdo_sqlsrv.log_severity => 0 => 0
sqlsrv
sqlsrv support => enabled
sqlsrv.ClientBufferMaxKBSize => 10240 => 10240
sqlsrv.LogSeverity => 0 => 0
sqlsrv.LogSubsystems => 0 => 0
sqlsrv.WarningsReturnAsErrors => On => On

And, finally, for using it, following the the sample scripts from the repository worked a charm.

PHP – Set Array Value from Closure Evaluation

There are times when you need to set a PHP array value from evaluated PHP code. Sometimes, you need to this using variables that won’t conflict with the current scope and with throwaway code that you won’t need again – so a closure is ideal.

Typically, you’ll need to assign the closure to a variable but this will negate the above requirement to not interfere with the current scope.

Here’s a way to do this:

return [
    'key1' => call_user_func( function() {
        $somevar = fn();
        // generate value
        return $calculated_value;
    }),
];

This has proved particularly used in Laravel configuration files.

Virtual Mail with Ubuntu, Postfix, Dovecot and ViMbAdmin

As part of pushing our new release of ViMbAdmin, I wrote up a mini how-to for setting up a virtual email system on Ubuntu where the components are:

  • Postfix as the SMTP engine;
  • Dovecot for IMAP. POP3, Sieve and LMTP;
  • ViMbAdmin as the domain / mailbox / alias management system via web interface.

It supports a number of features including mailbox archival and deletion, quota support and display of mailbox sizes (as well as per domain totals).

Find the how-to at:

Doctrine2 Provider for Laravel 4 Authentication

I’ve just added to the Doctrine2 service provider for Laravel by adding a UserProvider allowing Doctrine2Bridge to provide a driver for Laravel’s authentication system.

Simply put – this allows a Doctrine2 database table stroing users’ usernames and passwords to be used as the backend for Laravel 4 authentication.

Full documentation and examples can be found here. Available on Packagist and forkable on GitHub.

Doctrine2 Service Provider for Laravel 4

I’ve just released a Laravel 4 package which contains a service provider to the Doctine2 entity manager and the Doctrine2 cache. These are made available via facades named D2EM and D2Cache respectively.

Currently it uses the XML schema method for defining entities but this can easily be augmented with the other methods. Also, ArrayCache and MemcacheCache are fully supported caching interfaces. Any other cache that requires no configuration is also supported but some trivial coding will be required for caching backends required configuration.

Combining this with TwigBridge, we have an excellent framework with Laravel 4!

Nagios / Icinga Alerts via Pushover

I came across Pushover recently which makes it easy to send real-time notifications to your Android and iOS devices. And easy it is. It also allows you to set up applications with logos so that you can have multiple Nagios installations shunting alerts to you via Pushover with each one easily identifiable. After just a day playing with this, it’s much nicer than SMS’.

So, to set up Pushover with Nagios, first register for a free Pushover account. Then create a new application for your Nagios instance. I set the type to Script and also upload a logo. After this, you will be armed with two crucial pieces of information: your application API tokan/key ($APP_KEY) and your user key ($USER_KEY).

To get the notification script, clone this GitHub repository or just down this file – notify-by-pushover.php.

You can test this immediately with:

echo "Test message" | \
    ./notify-by-pushover.php HOST $APP_KEY $USER_KEY RECOVERY OK

The parameters are:

USAGE: notify-by-pushover.php  <$APP_KEY> \
    <$USER_KEY> <NOTIFICATIONTYPE>

Now, set up the new notifications in Nagios / Icinga:

# 'notify-by-pushover-service' command definition
define command{
    command_name notify-by-pushover-service
    command_line /usr/bin/printf "%b" "$NOTIFICATIONTYPE$: \
        $SERVICEDESC$@$HOSTNAME$: $SERVICESTATE$           \
        ($SERVICEOUTPUT$)" |                               \
      /usr/local/nagios-plugins/notify-by-pushover.php     \
        SERVICE $APP_KEY $CONTACTADDRESS1$                 \
        $NOTIFICATIONTYPE$ $SERVICESTATE$
}

# 'notify-by-pushover-host' command definition
define command{
  command_name notify-by-pushover-host
  command_line /usr/bin/printf "%b" "Host '$HOSTALIAS$'    \
        is $HOSTSTATE$: $HOSTOUTPUT$" |                    \
      /usr/local/nagios-plugins/notify-by-pushover.php     \
        HOST $APP_KEY $CONTACTADDRESS1$ $NOTIFICATIONTYPE$ \
        $HOSTSTATE$
}

Then, in your contact definition(s) add / update as follows:

define contact{
  contact_name ...
  ...
  service_notification_commands ...,notify-by-pushover-service
  host_notification_commands ...,notify-by-pushover-host
  address1 $USER_KEY
}

Make sure you break something to test that this works!

NOCtools and OSS_SNMP Get Support for Multiple Spanning Tree (MST) Protocol

NOCtools (a mixed bag collection of tools and utilities for NOC engineers) and OSS_SNMP (a PHP SNMP Library for People Who HATE SNMP, MIBs and OIDs) have just gotten support for Multiple Spanning Tree.

Specifically, OSS_SNMP has two new MIBS (Cisco’s original MST tree which has a lot of deprecated nodes – MIBS\Cisco\MST; and the newer IEEE tree – MIBS\Cisco\SMST). With these, we can, for example, get an array of [instanceID] => instanceName values from a switch by just coding:

$ciscosw = new \OSS_SNMP\SNMP( $ip, $community );
print_r( $ciscosw->useCisco_SMST()->instances() );

NOCtools has the more impressive use cases of these new features. Specifically (and just likes its RSTP/pvrspt functionality), it can:

  • Show MST port roles (root, designated, alternate, etc) for a given (or all) MST instance(s) – this is equivalent to the RSTP version;
  • From a given device, it can crawl all CDP neighbours and create a graph of all devices, their connecting ports and the MST roles of those ports. This is a really useful feature as it means you don’t need to log into multiple switches to get a handle on what links are blocking. See documentation and a sample diagram here.

Anonymous Objects in PHP

A little known but often useful feature of PHP’s object oriented functionality is anonymous objects which are generally used as value stores. Here’s an example:

$valueStore = (object) array(
    'name' => 'John Smith',
    'address' => array(
        '1 Some Street',
        'Some Town, Post Code',
        'Ireland'
    )
);

If you were to dump the resultant object, you’d get:

object(stdClass)#1 (2) {
    ["name"] => string(10) "John Smith"
    ["address"] => array(3) {
        [0] => string(13) "1 Some Street"
        [1] => string(20) "Some Town, Post Code"
        [2] => string(7) "Ireland"
    }
}

You can now add new items ($valueStore->item = 'qwerty'), check is items are set (isset()), remove items (unset()), and retrieve items ($valueStore->item).

But why? Well, a reason I use these anonymous objects for frequently is when I need to pass around a value store between different functions, objects, registries and so forth. With standard arrays, these are passed by value meaning you are making copies but also that changes on one won’t affect another.

If we use anonymous objects then these are passed by reference and no copies are created. We could use the reference operator I hear you scream. Yes, we could. But that is more prone to forgetful errors and is not as elegant as the above!

If you want to take it further, you can add functionality via anonymous functions and closures.

Centralised Logging

I’m currently looking at some centralised logging tools and the following stand out:

  • Octopussy – one I cam across a long time ago but looking at some of the others below it may be past its sell by date?
  • Graylog2 – GSOH (in dating parlance) – “Manage your logs in the dark and have lasers going and make it look like you’re from space.“
  • logstash – “a tool for managing events and logs. You can use it to collect logs, parse them, and store them for later use (like, for searching). Speaking of searching, logstash comes with a web interface for searching and drilling into all of your logs.“
  • Kibana - You have logs. Billions of lines of data. You shipped, dated it, parsed it and stored it. Now what do you do with it? Now you make sense of it… Kibana is an alternative browser based interface for Logstash… that allows you to efficiently search, graph, analyze and otherwise make sense of a mountain of logs.

Kibana has a Bootstrap UI and is written in PHP which immediately bumps it up my list 😉

Monitoring Asterisk via SNMP (with OSS_SNMP)

Over on the company blog, we just announced that we committed a complete Asterisk MIB implementation to OSS_SNMP in addition to a proof of concept Asterisk wallboard to NOCtools which includes active channels, uptime, version information and more.

Full details are on the company post but here’s a snippet of how easy it is to query Asterisk over SNMP:

 $host = new \OSS_SNMP\SNMP( $asteriskIP, $community );
 echo "Asterisk version: " . $host->useAsterisk()->version();
 echo "Active calls: " . $host->useAsterisk()->callsActive();
 echo "Calls processed: " . $host->useAsterisk()->callsProcessed();

And here’s a screenshot of the proof of concept Asterisk wallboard:

[NOCtools Asterisk Wallboard]
NOCtools – Asterisk Wallboard