Author Archives: Timothy Creswick

Manually debugging the SugarCRM REST API with cURL

The SugarCRM REST API is particularly difficult to debug; it’s full of bugs and inconsistencies in behaviour, and in general a malformed request simply returns an HTTP 200 code with the data string “null”. Nothing useful is posted in the application log. To that end, I have found it essential to have cURL at my [...]
Posted in APIs, Linux, PHP, SugarCRM | Leave a comment

Quickly see how many of your users are on Gravatar

A couple of the companies that I work with have wanted to evaluate the business case for integrating with Gravatar. In order to do this, we wanted to know how many of our users had Gravatar profiles, so I built this very simple PHP script which reads an input file containing email addresses (one per [...]
Posted in APIs, General, Linux, PHP | 2 Comments

Email files directly from the Linux console

It’s not a great habit to get into, but sometimes it can be very quick and convenient to email a file to yourself directly from a bash SSH console. Note: Because this uses email, this method isn’t secure. Think carefully about the contents of what you’re sending before you email files directly from your system. [...]
Posted in Debian, General, Linux, Systems Administration | Leave a comment

Debian APT repos not found? Switch to the archive!

If you’re running an older release of Debian and you’re seeing messages like this when you try and apt-get installs, then it’s probably because your release has been taken off the main mirrors and can no longer be updated that way. W: Failed to fetch 404 Not Found [IP: 80] W: Failed to [...]
Posted in Debian, Linux, Systems Administration | 4 Comments

Tuning JVM Memory Settings

Update: Andrew Wang’s blog post ( is a pretty nice quick guide, well worth reading in conjunction with this page. Sorting out sensible JVM memory settings in a production environment can be a tricky business. There are some great articles, blogs and lengthy white-papers out there explaining the details of how the JVM manages memory, [...]
Posted in Java, Systems Administration | Tagged , , , | Leave a comment

Twitter …finally

So I’ve finally got my act together and opened a twitter account. For anyone interested, I’m (@TimCreswick)
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Yubikey Glassfish Java Authentication Realm

Container-managed authentication is very useful in Java web applications; it saves writing a lot of back-end authentication and authorisation code into our applications, makes SSO (single sign-on) trivial between J2EE apps and also allows developers to hook into existing enterprise authorisation frameworks with relative ease. With our recent development work with the Yubikey, a one-time [...]
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Yubikey Authentication with Outlook Web Access

I’ve recently been evaulating Two-factor Authentication (2F) implementations for one of our clients, including the excellent Yuibikey product from Yubico. The initial requirement for our client project is 2F protection of all remote-access to their systems, which presently only amounts to VPN connections and webmail access via Outlook Web Access (OWA) provided by Exchange 2007. [...]
Posted in Security | Tagged , , , | 5 Comments

The business case for NFS backing stores with VMware ESXi

I mentioned in this post (relating to my Solaris ZFS / iSCSI management script) to the storage-discuss OpenSolaris mailing list that we were mostly using NFS as opposed to iSCSI for our ESXi backing stores, and was asked by Christoph Jahn to provide some background on this. Here’s my response as posted to the list: [...]
Posted in Virtualisation | Tagged , , , , | Leave a comment

Normal PDF viewing with Sony Reader PRS-505

My primary reason for buying an eBook Reader was for the large number of technical PDFs, white papers and carefully formatted user guides that I read for work. I found it very hard to find how well these pre-formatted PDFs would display on the device, with a lot of people saying that they were barely [...]
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