The Penguinlinux.com Blog

I have a virtual machine that we use for developers. Once the virtual machine boots up. Developers can then mount an SMB share using Windows or Mac. One user had a problem mounting his drive everytime
after entering his password the window will come back asking him for his password again.

Users on Lion didn’t have this issue only this user.

After some research I found the solution. At the login prompt

username: WORKGROUP\developer
password: %%PassWord%%% <— your password

That worked fine and solved our issues. We were able to mount the share.

Introduction

This guide is intended to provide you with simple instructions on how to install Nagios from source (code) on Fedora and have it monitoring your local machine inside of 20 minutes. No advanced installation options are discussed here - just the basics that will work for 95% of users who want to get started.

These instructions were written based on a standard Fedora Core 6 Linux distribution.

What You’ll End Up With

If you follow these instructions, here’s what you’ll end up with:

• Nagios and the plugins will be installed underneath /usr/local/nagios
• Nagios will be configured to monitor a few aspects of your local system (CPU load, disk usage, etc.)
• The Nagios web interface will be accessible at http://localhost/nagios/

Prerequisites

During portions of the installation you’ll need to have root access to your machine.

Make sure you’ve installed the following packages on your Fedora installation before continuing.

• Apache
• PHP
• GCC compiler
• GD development libraries

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As Nagios has a very simple plugin architecture, expanding the simple monitoring service from basic checks to full blown user tests is usually a case of increasing the capability of the plugins, or using new ones. Nagios Exchange has a large number of plugins that expand on the basics, providing more features.

check_http

The first on the list is the basic check_http plugin. This plugin comes bundled as part of the standard Nagios Plugins package, and is available as a package for most distributions, for example Debian has it named nagios-plugins-standard. If you’re using a package system, installing these plugins from this package will make your life easier as most of the command definitions will be handled for you. Lets throw some simple examples together:

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MongoDB includes basic authentication functionality. By default authentication is off. When off it is then required that one runs the database in a trusted (network restricted) environment.

Authentication is not available with sharding before v2.0. Older sharded environments must run with the database in a trusted environment.

Please also see the replica set authentication documentation.

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Most of this is distilled knowledge I gathered from the MongoDB documentation, credit for making such a good resource available for us to read goes to the Mongo team. I added some of my own conclusion where it made sense. They’re doing a great job documenting it, and I can highly recommend spending time to go through as much of it as possible to get a good overview of the whys and hows of MongoDB. Also, thanks to Mathias Stearn for hooking me up with some more details on future plans and inner workings in general. If you want to know more about its inner workings, there’s a webcast coming up where they’re gonna explain how it works.

Basics

Name stems from humongous, though (fun fact) mongo has some unfortunate meanings in other languages than English (German for example)
Written in C++.
Lots of language drivers available, pushed and backed by the MongoDB team. Good momentum here.
According to The Changelog Show ([1]) MongoDB was originally part of a cloud web development platform, and at some point was extracted from the rest, open sourced and turned into what it is today.
Collections

Data in MongoDB is stored in collections, which in turn is stored in databases. Collections are a way of storing related data (think relational tables, but sans the schema). Collections contain documents which have in turn keys, another name for attributes.
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MongoDB Administration

This is a write up of Mathias Stearn’s talk at the MongoUK conference, covering useful things for administrators to know when running MongoDB in production.

You can find Mathias on Twitter: @mathias_mongo.

Starting the server

Start the server like this:

$ mongod --dbpath /path/to/data

Stop it with Ctrl-C or with kill (but don’t use kill -9, which doesn’t give the server a chance to shut down cleanly and flush data to disk).

You can get one directory per database with the --directoryperdb option to mongod. This comes in handy if you want to put one database on a fast SSD filesystem, for example.

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Introduction

The openssl command-line binary that ships with the OpenSSL libraries can perform a wide range of cryptographic operations. It can come in handy in scripts or for accomplishing one-time command-line tasks.

Documentation for using the openssl application is somewhat scattered, however, so this article aims to provide some practical examples of its use. I assume that you’ve already got a functional OpenSSL installation and that the openssl binary is in your shell’s PATH.

Just to be clear, this article is strictly practical; it does not concern cryptographic theory and concepts. If you don’t know what an MD5 sum is, this article won’t enlighten you one bit—but if all you need to know is how to use openssl to generate a file sum, you’re in luck.

The nature of this article is that I’ll be adding new examples incrementally. Check back at a later date if I haven’t gotten to the information you need.

How do I find out what OpenSSL version I’m running?
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In situations where you have existing web sites on your server, you may find it useful to run Jenkins (or the servlet container that Jenkins runs in) behind Apache, so that you can bind Jenkins to the part of a bigger website that you may have. This document discusses some of the approaches for doing this.

Make sure that you change the Jenkins httpListenAddress from its default of 0.0.0.0 to 127.0.0.1 or any Apache-level restrictions can be easily bypassed by hitting the Jenkins port directly.

mod_proxy
mod_proxy works by making Apache perform “reverse proxy” — when a request arrives for certain URLs, Apache becomes a proxy and further forward that request to Jenkins, then it forwards the response back to the client.
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So at work the developers were having issues because when they hit control alt delete on their desktops sometimes if they were logged into vmware and using the vmware console the computer would reboot.

In the old Centos 5.7 you could disable control alt delete right on the /etc/inittab file but now with redhat 6 things have changed a little

cd into /etc/init
and edit the file control-alt-delete.conf

Change the current line to


exec /bin/echo "Control Alt Delete Has been Disabled"


That will take care of your problem.
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Ok so at work we have a guy who uses apache solar on a dev machine. He was having problems
doing Ajax Requests to Solr using JavaScript. The code he was writing should’ve been written using
JASONP but I don’t think he knew much JavaScript and wanted to just basically access solar directly
but the cross domain security restriction didn’t allow him to do that.

Here is more info in case you are curious. http://xplus3.net/2010/09/21/solr-and-jsonp/

http://jimbojw.com/wiki/index.php?title=Introduction_to_Cross-Domain_Ajax

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