Golang Concurrency Patterns

 Posted on 2017-10-28  |  5 minutes  |  934 words  |  inge4pres

In the early days of Go the language was often tailored towards “system programming” due to its C-stlye syntax and ability to write high-performance applications. Few time after, Go adoption was starting to gain traction for distributed systems development and projects like etcd, docker and kubernetes revealed the power of the networking capabilities offered by the internals in the language. Along the way a lot of libraries have been built around the powerful primitives offered by Go but in my opinion there is not enough use literature around the Communicating Sequential Processes implementation available through channels and goroutines, they are not even widely used in the standard library. [Read More]
golang  development 

Getting Started With Google Cloud Builder

 Posted on 2017-10-01  |  4 minutes  |  650 words  |  inge4pres

One of the advantages of containerized applications is the standardization, some would say “write it once, runs everywhere” but that’s another motto for another product. Anyway with a new packaging technology the same problems are faced: build reproducibility, or the necessity for people doing Ops to know they are going to deploy the same exact piece of code the Dev team used in their tests. So to address this issue the container image needs to be immutable: once it’s built, it’s not going to be changed, ever. [Read More]
gcp  cicd  development 

Automate TLS management on AWS with LetsEncrypt

 Posted on 2016-12-03  |  3 minutes  |  514 words  |  inge4pres

Letsencrypt is cool: automated, free TLS certificates for everybody! They are sponsored mainly by internet corps and they started a crowd-funding campaign to avoid the influence of this corps in the future of the project. I recently moved the blog to hugo on AWS and I’m now porting the TLS management scripts I wrote a while ago on AWS: this is a nice exercise to give a proper TLS automation valid for everyone on AWS. [Read More]
aws  tls  letsencrypt 

4pres goes #serverless

 Posted on 2016-11-17  |  4 minutes  |  713 words  |  inge4pres

Last month I felt I was a little late for the #serverless party going on all over the internet and I started taking a look at what the pros and cons would be to actually not manage any server myself. Shutting down my VPS hosting my apps I will lose my mail server, my MySQL instances and my Docker registry but: who cares? There are cloud services I can use with hundreds of times more availability and for a fraction of the cost. [Read More]

Moving the blog to hugo

 Posted on 2016-10-10  |  1 minutes  |  208 words  |  inge4pres

In times of experimenting, I am now having a lot of fun with docker, rkt, kubernetes and containers ecosystem in general. But one thing I never forget to play with is content editing and publishing! So here I am, trying to migrate all my blog and website to Hugo :) So instead of a bare VPS I am moving my blog to AWS S3 + Cloudfront CDN. This will be more scalable and far less expensive. [Read More]

A benchmark of AWS EFS

 Posted on 2016-09-18  |  4 minutes  |  671 words  |  inge4pres

Amazon Web Services Elastic File System has been to my knowledge the service to have the longest beta testing period: reason for this may be that not as many client as expected tested it and AWS received too few feedback on it or that there were issues not to release GA. I don’t want to speculate on which one is correct but now that it has been officially released I decided to give it a try and of course compare it to a self-managed solution on the same platform. [Read More]
aws  benchmark  cloud  EFS  filesystem 

AWS IAM policy to let users manage their own MFA

 Posted on 2016-04-06  |  2 minutes  |  273 words  |  inge4pres

If you’re an AWS administrator you know that managing web console security is pretty tough unless you know what you want and you know what you’re doing. So if what you want is let each AWS user manage their own MFA device configuration without you and force them to have MFA active to use the web console, here is your solution. TL;DR Create one or more groups with your web users Create a new policy using this JSON Attach the policy to the group(s) How does it work? [Read More]
aws  cloud  iam  mfa  policy 

Implement a generic data list structure

 Posted on 2016-01-24  |  2 minutes  |  332 words  |  inge4pres

As a coding challenge I was asked to provide a generic list implementation using a language of my choice and using only primitive types, avoiding the use of high level built-ins. I chose Go because I want to learn it and I know it can be useful to create an abstract, generic implementation. The challenge request to implement at least 4 methods on the generic type: Filter() – returns a subset of the List satisfying an operation Map() – returns the List objects’ map Reverse() – reverse the ordering of the List objects FoldLeft() – join the objects from left to right using a join character As a bonus question I was asked to code unit tests for the aforementioned methods and give an explanation on how the implementation guarantees concurrent access on resources. [Read More]
aws  challenge  coding  design  golang  software 

Virtualize an old Windows PC

 Posted on 2016-01-24  |  4 minutes  |  710 words  |  inge4pres

A friend asked me if I was able to get back working a Windows 98 PC he had in his house; I have never done it so I said “sure I can!” just to have the opportunity to learn something new, and of course do a friend a favour. My idea was to copy the whole PC and get it running on a virtual machine thus doing what I later discovered is called a “P2V” (Physical to Virtual); the result of which would have been a portable VM which I could then install in my friend laptop to have his old PC back. [Read More]
geek  guide  oldies  virtualization  windows 

Golang Message Queue: a simple TCP message bus

 Posted on 2015-08-02  |  2 minutes  |  387 words  |  inge4pres

[TL;DR] I wrote a Pub/Sub message queue in Go, branch “master” is stable but missing some interesting feature like distributed memory synchronization between nodes in a cluster and encryption. Code at https://github.com/inge4pres/gmq Being a cloud system engineer, my work is to design and implement distributed systems: one of the key principles in designing such architectures is decoupling, which means ensuring the many parts composing the system are able to share informations and complete a sequence of operations without being tied together. [Read More]
cloud  development  golang  software