mhmxs tech.log

Nowadays everything is Cloud Native; everybody talks about CN tools, frameworks, solutions, and so on. On the other hand, those tools totally changed the way we design, develop, test and release modern applications. I think the number of issues that we solved with the new concepts is equal to the number of new challenges, so in short,     we simply shoveled problems from one hole to the other. Many new tools appeared on the market to make developers' life easier by integrating software with the underlying infrastructure watching file changes and building containers automatically generating resource descriptors on the fly allowing debugging in a running container etc. Next to the new tools, new programming languages such as Metaparticle , Pulumi or Ballerina have been born. The last one had my attention because others are extensions on top of some existing languages, while Ballerina is a brand new programming language, des...

Golang has a nice built-in framework for testing production code and you can find many articles on how to use it. In this blog post, I don't want to talk too much about the basics , table-driven testing ,  how to generate code coverage  or detect race conditions . I would like to share my personal experiences with a real-world scenario. Go is a relatively young and modern programming language on one side, and it is an old fashion procedural language on the other. You have to keep in mind that fact when you are writing production code from the beginning, otherwise, your program should become an untestable mess so easily. In a procedural way, your program is executed line by line and functions call other functions without any control of the dependencies. Hard to unit test, because you are testing underlying functions too, which are side effects from the perspective of testing.  It looks like everything is static if you are coming from object-oriented world. There are...

In my company, we use Java and Go as our development platforms and of course, sometimes those projects have to communicate with each other. In the current blog post, I would like to introduce our solution to sign messages on the Java side and verify them in a Go service. First, let's talk a bit about architecture. Our Java application spins up new virtual machines in the cloud, and the base image of the instance contains a small Go service. That service is the main entry point of our configuration management system, and we don't want to allow any operation from untrusted clients to modify nodes. Two-way SSL with a signature in the request sounded fair enough to trust in clients. Both components are open source, we don't have any "secret" in the binaries, so we elected RSA asymmetric key pairs to generate and verify signatures. Java has the private key and Go has the public one. Time to go deeper. Java is an old platform (personally I have many years of experi...