sysadmin

Bookmarks for 18 apr 2014 through 30 apr 2014

These are my links for 18 apr 2014 through 30 apr 2014:

  • JoshData/mailinabox · GitHub – Mail-in-a-Box helps individuals take back control of their email by defining a one-click, easy-to-deploy SMTP+everything else server: a mail server in a box.
  • SSH Multi-hop Connections With Netcat Mode Proxy | Click & Find Answer ! – Since OpenSSH 5.4 there is a new feature called natcat mode, which allows you to bind STDIN and STDOUT of local SSH client to a TCP port accessible through the remote SSH server. This mode is enabled by simply calling ssh -W [HOST]:[PORT] Theoretically this should be ideal for use in the ProxyCommand setting in per-host SSH configurations, which was previously often used with the nc (netcat) command. ProxyCommand allows you to configure a machine as proxy between you local machine and the target SSH server, for example if the target SSH server is hidden behind a firewall. The problem now is, that instead of working, it throws a cryptic error message in my face: Bad packet length 1397966893.Disconnecting: Packet corrupt
  • Tyblog | SSH Kung Fu – OpenSSH is an incredible tool. Though primarily relied upon as a secure alternative to plaintext remote tools like telnet or rsh, OpenSSH (hereafter referred to as plain old ssh) has become a swiss army knife of functionality for far more than just remote logins. I rely on ssh every day for multiple purposes and feel the need to share the love for this excellent tool. What follows is a list for some of my use cases that leverage the power of ssh.
  • Baseimage-docker: A minimal Ubuntu base image modified for Docker-friendliness – YOUR DOCKER IMAGE MIGHT BE BROKEN without you knowing it Learn the right way to build your Dockerfile.
  • NetApp – Index – The following documentation is a guide on using and configuring the NetApp servers, there is also a commandline cheat sheet. I have tried to make this section as brief as possible but still cover a broad range of information regarding the NetApp product but I point you to the Official NetApp web site which contains all the documentation you will ever need.

Bookmarks for 10 apr 2014 through 15 apr 2014

These are my links for 10 apr 2014 through 15 apr 2014:

  • ditaa – ditaa is a small command-line utility written in Java, that can convert diagrams drawn using ascii art ('drawings' that contain characters that resemble lines like | / – ), into proper bitmap graphics. This is best illustrated by the following example — which also illustrates the benefits of using ditaa in comparison to other methods 🙂
  • RegExr: Learn, Build, & Test RegEx – RegExr is an online tool to learn, build, & test Regular Expressions (RegEx / RegExp). * Results update in real-time as you type. * Roll over a match or expression for details. * Save & share expressions with others. * Explore the Library for help & examples. * Undo & Redo with Cmd-Z / Y. * Search for & rate Community patterns.
  • BASH with Debugger and Improved Debug Support and Error Handling – The Bash Debugger Project is a source-code debugger for bash that follows the gdb command syntax. The version 4.0 series is a complete rewrite of the previous series along the lines of my other POSIX shell debuggers and other debuggers mentioned below.
  • Opencall – Open Source Call Tracking Software – Call tracking is a method of monitoring inbound phone calls. It allows you to record conversations, track key statistics such as caller id, call duration, call source and streamline your sales, customer service and marketing. Opencall is the world’s first (and only) open source call tracking software. The software is available under the GPL v3 license, is written in PHP and utilises MySQL as the database platform. The original Opencall source code was written and developed by CallTracking Hong Kong to service clients in Hong Kong and other Asian countries. After 8 months of internal development the founder of CallTracking, Scott Bowler, decided to release their proprietary code to the public and change his business model to servicing companies who would make use of the open source call tracking platform. The major driver behind this choice was to open up the product to a global user base and encourage more rapid development of the platform.

Bookmarks for 1 apr 2014 from 13:31 to 14:21

These are my links for 1 apr 2014 from 13:31 to 14:21:

Bookmarks for 28 mar 2014 through 29 mar 2014

These are my links for 28 mar 2014 through 29 mar 2014:

  • LDAP org chart | bitcube.co.uk – For centralised authentication and authorisation, LDAP is the de-facto standard. Whether in its pure form on Unix or in Active Directory guise on Windows, everyone uses it. What many people don't realise is that you can store all sorts of useful (and not so useful) information in LDAP. One field which can be useful is the "manager" attribute. One of our customers use that and so we've written a small script to graph it using the excellent Graphviz tool. It will probably need customising for specific cases, however we hope that people find it useful nonetheless. If you want to alter the output, do have a look at the record format documentation.
  • Puppet errors explained | bitcube.co.uk – Puppet is a wonderful system automation tool, however the learning curve can be a little steep. We've collected some of the errors messages and "strange" behaviour you may come across together with explanations to help overcome these hurdles and boost adoption of this fabulous tool. If you have any useful errors and explanations, please do send them in and we'll update this article.
  • SCAP: Guide To The Secure Configuration of Red Hat Enterprise Linux 5 – This guide has been created to assist IT professionals, in effectively securing systems with Red Hat Enterprise Linux 5.
  • DNS Load Balancing and Using Multiple Load Balancers in the Cloud – […] Load balancing in general is a complicated process, but there's some secret sauce in managing DNS along with multiple load balancers in the cloud. It requires that you draw from a few different sets of networking and “cloudy” concepts. In this second article in my best practices series (my first post covered how to use credentials within RightScale for storing sensitive or frequently used values), I'll explain how to set up load balancers to build a fault-tolerant, highly available web application in the cloud. Here's what you’ll need: Multiple A records for a host name in the DNS service of your choice Multiple load balancers to protect against failure […]
  • gdnsd – gdnsd is an Authoritative-only DNS server which does geographic (or other sorts of) balancing, redirection, weighting, and service-state-conscious failover at the DNS layer. gdnsd is written in C using libev and pthreads with a focus on high performance, low latency service. It does not offer any form of caching or recursive service, and notably does not support DNSSEC. There's a strong focus on making the code efficient, lean, and resilient. The code has a decent regression testsuite with full branch coverage on the core packet parsing and generation code, and some scripted QA tools for e.g. valgrind validation, clang-analyzer, etc. The geographically-aware features also support the emerging EDNS Client Subnet draft for receiving more-precise network location information from intermediate shared caches.

Bookmarks for 25 mar 2014 through 28 mar 2014

These are my links for 25 mar 2014 through 28 mar 2014:

  • blblack/gdnsd – gdnsd is an Authoritative-only DNS server. The initial g stands for Geographic, as gdnsd offers a plugin system for geographic (or other sorts of) balancing, redirection, and service-state-conscious failover. The plugin system can also do things like weighted address/cname records. If you don't care about these features you can ignore them :).
  • How to Create and Apply Patches in GIT using diff and apply Command – Creating a patch in GIT is a great way to share changes that you are not yet ready to push to a public branch of a project.
  • Your own Dynamic DNS in 3 steps | The Nexus – This is a "niche" post: it will really only appeal to you if you have access to your own — or a friend's — name servers and want to use your own domain to track your dynamic IP addresses, such as your home router's. You will still have to buy your own domain, cheap if you go to internet.bs or namecheap.com. I hear that the latter even provide their own dynamic DNS service although I cannot tell you anything about its quality/flexibility. So, why this post? It's for you, my friends, budding entrepreneurs who wish to bootstrap your business and know that every cent counts. Maybe you feel that you could host your product's web site on a home computer. Maybe you need more control over what happens on that server. Or maybe you want to be able to log on to your development machine from anywhere in the world. Whatever your reasons, you're still here. So let's get started.
  • Apache – Prefork or Worker | Code Bucket – Apache is the most common and famous webserver. Everyone knows about apache and most of us also have hands on experience with apache. But few of us know that apcahe2 comes with 2 multi processing modules(MPMs): 1. Prefork 2. Worker
  • Ottimizzazione di Apache, dall’analisi ai parametri – […] I recenti sviluppi nel campo della virtualizzazione hanno accelerato la moltiplicazione di ambienti virtuali vps a basso costo, molto convenienti ma a volte carenti dal punto di vista delle risorse di sistema. Molto spesso questi ambienti vengono utilizzati a scopo di testing o come ambienti di produzione all'interno dei quali viene implementato l'utilizzo di un web server. Apache, come ben sappiamo ,e uno dei web server piu diffusi e nella maggioranza dei casi rappresenta la scelta di default su un grandissimo numero di installazioni […]

Bookmarks for 24 mar 2014 from 13:13 to 18:33

These are my links for 24 mar 2014 from 13:13 to 18:33:

  • ZPanel | The free web hosting panel – ZPanel is an easy to use, enterprise class web hosting control panel with support for unlimited resellers. From the largest business to SOHO or development environments, ZPanel can support your needs.
  • Bucky — Performance Measurement of Your App’s Actual Users – Bucky is a client and server for sending performance data from the client into statsd+graphite, OpenTSDB, or any other stats aggregator of your choice. It can automatically measure how long your pages take to load, how long AJAX requests take and how long various functions take to run. Most importantly, it's taking the measurements on actual page loads, so the data has the potential to be much more valuable than in vitro measurements. If you already use statsd or OpenTSDB, you can get started in just a few minutes. If you're not collecting stats, you should start! What gets measured gets managed.
  • Linux on 4 KB sector disks: Practical advice – Advanced Format disks use 4,096-byte sectors rather than the more common 512-byte sectors. This change is masked by firmware that breaks the 4,096-byte physical sectors into 512-byte logical sectors for the benefit of the operating system, but the use of larger physical sectors has implications for disk layout and system performance. This article examines these implications, including benchmark tests illustrating the likely real-world effects on some common Linux file systems. As Advanced Format disks have become the norm, understanding how to cope with these disks is a vital skill for anyone who wants to avoid serious performance penalties associated with suboptimal configuration.
  • WPScan by the WPScan Team – WPScan is a black box WordPress vulnerability scanner.
  • SiteSucker for OS X – SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet. It does this by asynchronously copying the site's Web pages, images, backgrounds, movies, and other files to your local hard drive, duplicating the site's directory structure. Just enter a URL (Uniform Resource Locator), press return, and SiteSucker can download an entire Web site. [ via http://onethingwell.org/post/79174700058/sitesucker ]

Bookmarks for 3 mar 2014 through 4 mar 2014

These are my links for 3 mar 2014 through 4 mar 2014:

  • Centos yum 404 repository errors | Natural Order Development – […] Basically yum ran through every single mirror and got nothing but 404 errors. I thought something might have gotten broken with yum or maybe the entire Internet changed overnight to a new repository layout (not likely but it has happened before). Well a simple Google for yum 404 led to some message threads that basically said yum's caches were out of data […]
  • Avoiding reboot: Resetting USB on a Linux machine – Every now and then, some USB device misbehaves badly enough to knock out the entire interface, to the extent that the system doesn’t detect any new USB devices. Or work so well with the existing ones, for that matter. The solution for me until now was to reboot the computer. But hey, I don’t like rebooting Linux!
  • AfterLogic WebMail Lite — free ajax webmail – Fast and easy-to-use webmail front-end for your existing IMAP mail server, Plesk or cPanel

Bookmarks for 26 feb 2014 through 3 mar 2014

These are my links for 26 feb 2014 through 3 mar 2014:

  • Introducing Kite ! – Kite is a gmail clone you can install on a server of your own. It's pretty limited for the moment, but I hope to get something usable in the next few months.
  • Mailpile: Let’s take e-mail back! – Mailpile is email software (an app) that runs on your desktop or laptop computer. You interact with the program using your web browser. The goal of Mailpile is to allow people to send e-mail in a more secure and private manner than before.
  • xml2csv-conv – Command line XML to CSV converter – Google Project Hosting – xml2csv-conv is command line tool for converting data from XML schema to CSV. The tool has many command line options. The software is platform independent and was written in Java language.
  • Authenticating other services against AD – SambaWiki – Maybe you finished setting up your new/migrated samba4 domain and having now the job to hook up several other services to Active Directory or LDAP. Then you will find here a place for configuration examples. Please keep in mind, that some of the examples here may only work on specific plattforms and/or distributions and have to be adapted.
  • Eight Ways to Blacklist with Apache\’s mod_rewrite | Perishable Press – With the imminent release of the next series of (4G) blacklist articles here at Perishable Press, now is the perfect time to examine eight of the most commonly employed blacklisting methods achieved with Apache’s incredible rewrite module, mod_rewrite. In addition to facilitating site security, the techniques presented in this article will improve your understanding of the different rewrite methods available with mod_rewrite.

Bookmarks for 20 feb 2014 through 21 feb 2014

These are my links for 20 feb 2014 through 21 feb 2014:

  • Home · globocom/thumbor Wiki – Thumbor is a smart imaging service. It enables on-demand crop, resizing and flipping of images. It also features a VERY smart detection of important points in the image for better cropping and resizing, using state-of-the-art face and feature detection algorithms (more on that in Detection Algorithms). Using thumbor is very easy (after it is running).
  • np1/mps-youtube – Features: Search and play audio/video Create local playlists Download audio/video Works with Python 2.7 and 3.x Works with Windows, Linux and Mac OS X Requires mplayer This project is based on mps, which is a terminal based program to search, stream and download music. This implementation uses YouTube as a source of content and can play and download video as well as audio. The pafy library handles interfacing with YouTube.
  • Customizing and monitoring Linux system startup – Minimizing the amount of time required to boot a computer system is important regardless of whether you are turning on your home computer or restarting a server that provides services to thousands of users. This article discusses the various system startup and shutdown mechanisms that are used on different Linux® distributions. It explains how to integrate new services, customize existing startup configurations, and examine the behavior and performance of system startup configurations.
  • Cockpit Project – Cockpit is a server manager that makes it easy to administer your GNU/Linux servers via a web browser.

Bookmarks for 18 feb 2014 from 01:19 to 22:32

These are my links for 18 feb 2014 from 01:19 to 22:32:

  • SubGit :: Svn To Git Migration – What is SubGit SubGit is tool for a smooth, stress-free Svn to Git migration. Create writable Git mirror of a local or remote Subversion repository and use both Subversion and Git as long as you like. Version 2.0 of SubGit introduces support for a remote Subversion repositories, so that to build a Git mirror, no shell access to Subversion repository is required (see complete release notes for a new version). […] You may use SubGit for evaluation purposes without a registration as long as you like. During that evaluation period SubGit will remind you on a necessity of registration with the help of post commit and post receive messages.
  • Apache Tips & Tricks: Deny access to some folders – MDLog:/sysadmin – Applies: apache 1.3.x / apache 2.0.x Required apache module: mod_access Scope: global server configuration, virtual host, directory, .htaccess Type: security Description: How to deny access to certain folders and the files inside them. Useful: to deny access to certain folders containing private information (log files, source code, password files, etc.). The example shown here will address the question posted by Saul Howard on how to deny access to all the subversion directories (.svn).
  • Polipo — a caching web proxy – Wikipedia: Polipo is a lightweight forwarding and caching web proxy server. Polipo is HTTP 1.1-compliant, supports IPv4, IPv6, traffic filtering and privacy-enhancement. To minimize latency, Polipo both pipelines multiple resource requests and multiplexes multiple transactions onto the same TCP/IP connection.[1] Polipo is free software[2] released under the MIT License.[3] It runs on GNU/Linux, OpenWrt, Microsoft Windows, Mac OS X, and FreeBSD. Polipo can be configured to use on-disk cache and serve cached content when offline and perform various forms of content filtering[…] E può usare upstream proxy socks… per chi se ne intende 😉