An unambiguous best practice for systems is to codify your infrastructure in a repeatable text format, rather than clicks in a UI. The common name for this is Infrastructure as Code. By far, the two most popular ways to do this, especially in AWS, are Terraform and CloudFormation. I used…

Table driven tests are a popular model for testing in Go and a clear improvement to traditional testing of one function per case. However, there’s an alternative style that can often be clearer than table driven tests that relies on function closures. I’ll reference the example code on Dave Cheney’s…

Histograms are an important part of metrics and monitoring. Unfortunately, it is computationally expensive to accurately calculate a histogram or quantile value. A workaround is to use an approximation and a great one to use is t-digest. Unfortunately again, there’s no such thing as an accurate approximation. …

Misused abstraction causes a vulnerability in the go-redis client — A recent vulnerability in the go-redis library allowed correctly configured clients to return the results of other redis commands in the event of redis failures. While all code is subject to bugs, this one could have been prevented if proper care was taken when creating and using interfaces. Bug behavior Most clients…

Protecting against memory leaks — Problem You have a constructor function that creates an object with a background goroutine. You want the object to garbage collect itself even if people don’t explicitly close it. This isn’t possible since since the background goroutine is always running and pointing to your created object. Solution Wrap the returned object and…

Problem You’ve written an object or class. It’s somewhat complex and you want to iterate ways to better abstract your code but are unsure how to start. There exists documentation about what good abstraction looks like, but no concrete iterative steps. Being deep inside your own code can make you blind…

Problem Example I commonly see bugs appending to slices in Go in a way that is not thread safe. A simple example is the unit tests below. This test has two goroutines append to the same slice. If you run this test with the -race flag, it works just fine. Now…

I had an integration test that was very complex (most are, sadly) and took too long to start. I was able to diagnose why using new features of Go’s 1.10 trace tool. This post describes my workflow and what led me there. The example code I’m using for this post…

A short checklist of what I wish for in a good Go library, in no particular order. This is a companion to the effective go list, Go code review comments list, and Go proverbs list. In general, when given two reasonable ways to do something, defer to the option that…