Smaller Docker images with multi-staging
 docker  devops
From my experience, there are two main use cases for Docker: creating an output container with the applications that can be deployed somewhere, and creating a container with development dependencies (eg. language, database versions) that allow you to build/compile it without having everything installed on your machine. You can do both at the same time, but it used to result in huge images that go to production. Thankfully, there is a better way now - multi-stage builds.
Testing Go with custom check functions
 golang  testing
Some time ago I ran into an example source code of the standard library with some interesting approach to writing unit tests. At first, it felt strange, but I decided to apply it to my everyday routine and realized how awesome it is. I always put readability of my source code as a top priority, that's why I adopted custom check functions in my tests.
Reading password input in Go
 golang  security
Recently I've been working with an internal Go tool that uses environment variables for accessing user credentials that are being used to authenticate. While I find that very handy, I was wondering how difficult would it be to add the functionality of providing the password manually, but in a safe (non-displaying) way. As it turned out, it cannot be any easier!
Accept Interfaces Return Struct in Go
One of the first things I've learned when starting working with Go was that it has so-called _proverbs_. They are a list of rules, which sound like some smart quotes, which should guide you during your journey. For a long time, I didn't quite understand why I should _accept interfaces but return structs_. I wanted to return interfaces as well since this would define what my return type does, not what it is exactly. It struck me almost a one full year or working with Go exclusively, how wrong I was. This post explains my line of thought, I hope it might save some of you sometime before you have your _Aha!_ moment.
Restricting access to Vault
 vault  tools
We've already seen the basics of Vault and wrote some code to access it in the last posts, this time we'll focus on two aspects that allow us to have more control over who can do what with our vault. Let's dive into it.
Accessing Vault with Go
 vault  tools
I the previous post we talked about the basics of Vault, its architectural concepts, nomenclature and basic operations that can be performed. Now it's time to turn that theory into practice and write some code in Go that will allow us to access our secrets.
Introduction to Vault
 vault  tools
We all have something to hide, I think everyone has to admit that. Being a developer you need to store lots of passwords, tokens, addresses and other pieces of information that you should not reveal to anyone. You could keep them all in a text file, but a part of you knows that you really should not. What are the alternatives? Let's look at one of them, Vault, which is an awesome project by Hashicorp.
Hosting static website on Github
 webdev  github
Building web applications take much time, but what if you want to create a small website, like a business card? If you are fine with a simple, static content and you are a developer, there is just a perfect place to have it set up in seconds. This post describes how you can create your own site using Github.
Go struct tags with mappy
One of the things developers like about Go is that it has strong typing, which means that the compiler takes care of making sure that if you expect a string or a number, you will get one. Unfortunately, this approach has limitations, for example, it would be difficult to parse JSON structures since they come from the "outside world". This blog post shows how you can use one specific package from the standard library so that you can handle situations like those.
HTTPS in no time with Caddy
 security  webdev
I've never been any kind of expert on software security, but I've always known that HTTPS beats HTTP at all times. I know that the communication in the latter is not encrypted and your data can be stolen. I always thought that it takes a great deal of effort to secure the connection, but lately, I discovered how little you actually need, thanks to Let's Encrypt and Caddy.