Ioannis Canellos iocanel

Prologue

These are just some personal notes, that I’ll surely forget unless I write them down.

The problem

As I am bloging for over a decade now and most of the time I am sharing code, I needed of a decent way to highlight my code and make it available to users. In the beginning I was using blogger but later on I migrated to wordpress.

So, I needed a syntax highlighting solution similar to what I was using for blogger.

This is not a blog post. This is my Emacs powered nutrition tracker!

No, I mean it!

It’s the one file that contains all the code, templates and data of my tracker, exported in html.

Keep reading, to see how you can harness the power of emacs and org mode to track your nutrition and even generate cool graphs like:

For quick demo you can check this short Youtube demo: Nutrition tracking using Emacs.

Overview

This is a small post that describes how I made authoring markdown, org-mode etc easier by using snippets that help me handle links like a pro.

Prologue

I am a heavy user of org-mode. I use it for taking notes, writing blogs, presentations and so on. As a software developer I often use markdown too. In both cases at some point I have to deal with links.

Embarrassingly enough, I used to rely on my browsers bookmarks to handle links, so my workflow looked a little like:

Prologue

Every now then I see on social media people sharing the same old story: “Using shell scripting to workaround the limitations of their DevOps tools”. I’ve done it, my colleagues are doing it and most likely you have done it yourself.

So it seems that shell scripting is used to do the dirty work, yet its often considered by many the last resort. If you search on the web about popular ‘DevOps’ tools and skills, you’ll probably find:

Prologue

Lately I keep hearing about “how much software development has changed over the last half of the decade”. This usually refers to the adoption of containers, cloud etc. I would like to focus on an other factor of the change and that is the plethora of development related systems and services.

So its typical for a team to have:

• version control
• code review systems
• code analysis systems
• project management
• issue trackers
• continuous integration
• chat / messaging

Add email to that and you realize that most of development related tasks now days take place in the browser. Unfortunately, browsers by nature are unaware of the content they serve, so its not trivial to automate your workflow in the browser. So, if the browser is not going to play the role of ‘Swiss army knife’ for development then what?

intro

openshift takes security seriously. Sometimes more seriously than I’d like (mostly cause I am lazy). One such example is the fact that containers run using arbitrary users. This is done as an extra measure to control damages, should a process somehow escapes its container boundaries.

But how does it affect users?

the problem

Users need to follow certain guidelines when creating container images.

don’t assume a user

you don’t have a known uid The uid of the user is not known in advnace. Also there is no way of controlling it.

Prologue

Yesterday I was having a talk with Adrian Cole and during our talk he had an unpleasant surprise. He found out that he forgot a node running on his Amazon EC2 for a couple of days and that it would cost him a several bucks.

This morning I was thinking about his problem and I was thinking of ways that would help you avoid situations like this.

My idea was to build a simple project that would notify you of your running nodes in the cloud via email at a given interval.

Prologue

This post intents to point out some pitfalls when using spring aop and reflection on the same objects. Moreover, it provides some examples of these pitfalls when combining ServiceMix & Camel with Spring JPA/Hibernate.

The two most common uses of aspect oriented programming with spring are:

• Security
• Transation Handling

I found myself having issues when applying those 2 on beans that are accessed using reflection (not in all cases) and below I am going to dig into those issues.

Prologue

This is the first from a series of posts that demonstrate how to extend ServiceMix management using Spring’s jmx and aop features. The version of SerivceMix that is going to be used will be 3.3.3-SNAPSHOT but I’ve been using this technique since 3.3 and it will probably can be applied to 4.x.

Problem

One of the most common problems I had with servicemix was that even the most simple changes in the configuration (e.g. changing the name of the destination in a jms endpoint) required editing the xbean.xml of the service unit and redeployment. Moreover this affected the rest of the service units contained in the service assemblies, which would be restarted too.

In the previous post Extend ServiceMix Management features using Spring – Part 1 I demonstrated a very simple technique that allows you to expose endpoint lifecycle operations via jmx. Now I am going to take it one step further and expose the endpoint configuration via jmx.

If you haven’t done already please catch up by reading Part 1.

Part II: Modifying the configuration of a live endpoint

I am going to use the wsdl-first servicemix sample as modified in the previous post and expose the property locationURI of the HttpEndpoint to jmx using Spring’s @ManagedAttribute annotation.

In the previous post Extend ServiceMix Management features using Spring – Part 2 I demonstrated how to use spring to gain control over endpoint lifecycle and configuration via jmx. You might wonder till now “what happens to those custom changes if I have to redeploy the assembly, restart servicemix or even worse restart the server?”. The short answer is that these changes are lost. The long answer is in this blog post, which explains how to persist those changes and how to make the endpoint reload them each time it starts.

Prologue
This is the first from a series of posts that demonstrate how to extend ServiceMix management using Spring’s jmx and aop features. The version of SerivceMix that is going to be used will be 3.3.3-SNAPSHOT but I’ve been using this technique since 3.3 and it will probably can be applied to 4.x.

Problem
One of the most common problems I had with servicemix was that even the most simple changes in the configuration _(e.g. changing the name of the destination in a jms endpoint)  _required editing the xbean.xml of the service unit and redeployment. Moreover this affected the rest of the service units contained in the service assemblies, which would be restarted too.