About the main function

I love how simple Go’s entry point main function is. It is where your code will start when someone runs your program.

package main

func main() {
 // stuff
}

However, main is difficult to test, and it’s not clear how we access the environmental dependencies our program has, such as stdin, stdout, the command line args, the environment variables themselves, etc.

https://pace.dev/blog/2020/02/12/why-you-shouldnt-use-func-main-in-golang-by-mat-ryer.html

How to build a terminal dashboard in Golang in 300 lines of code using termui.

https://levelup.gitconnected.com/building-a-terminal-dashboard-in-golang-in-300-lines-of-code-3b9f83f363a8

Microservices

Hello, world!\n 😄
This week I came across my notes and bookmarks and made a list of resources where to start learning about microservices, and I’d like to share it here. Hope it’s gonna be useful.

📒Posts & Articles:
- 35 Microservices Interview Questions You Most Likely Can't Answer: https://dev.to/aershov24/35-microservices-interview-questions-you-most-likely-can-t-answer-2eoc
- Martin Fowler’s microservices, classic: https://martinfowler.com/articles/microservices.html
- Nice intro into Microservices topic from NGINX team: https://www.nginx.com/blog/introduction-to-microservices/

📚A book to read: “Building Microservices: Designing Fine-Grained Systems” - https://www.amazon.com/Building-Microservices-Designing-Fine-Grained-Systems-ebook/dp/B00T3N7XB4

🧑‍🏫Tutorials
🔴If you’d like to start from practice in a hard mode, feel free to go here:
- “Introduction to Microservices in Go” https://ewanvalentine.io/microservices-in-golang-part-0/ This is a big and somewhat complete series/tutorial of building a service from scratch in Go, including docker, CI configuration, deployment, Kubernetes and much more things.

🟢Easy-going practices are:
- An option with MySQL: “Build a REST API as a Go microservice together with MySQL” -https://dev.to/johanlejdung/a-mini-guide-build-a-rest-api-as-a-go-microservice-together-with-mysql-27m2
- MongoDB-based example: “Microservices: An Example With Docker, Go, and MongoDB” - https://dzone.com/articles/microservices-an-example-with-docker-go-and-mongod

Interesting reading about a tool that examines your Go code and recommends optimal struct field arrangements to help improve memory efficiency:

https://medium.com/orijtech-developers/efficient-struct-packing-guided-pass-for-go-92255872ec72

Making SQLite faster in Go 🚀

The most popular way of using sqlite in Go happens to also be the slowest when using it in a concurrent application like a web app. Roll your own connection pool to speed things up.

https://turriate.com/articles/making-sqlite-faster-in-go

Discovering and exploring

mmap

(memory-mapped files) using Go

mmap

is a system call for mapping files into memory which can provide a neat abstraction for working with both. Here’s how to use it in Go along with when you shouldn’t.

https://brunocalza.me/discovering-and-exploring-mmap-using-go/

Go 1.16 Release Candidate 1 is released!

Go 1.16, due to have its final release in February, is now taking its final form and is ready for your production testing, say the Go team.

>>>
It is cut from release-branch.go1.16 at the revision tagged go1.16rc1. Please try your production load tests and unit tests with the new version, your help testing these pre-release versions is invaluable.

Report any problems using the issue tracker: https://golang.org/issue/new

If you have Go installed already, the easiest way to try go1.16rc1 is by using the go command:

$ go get golang.org/dl/go1.16rc1
$ go1.16rc1 download

You can download binary and source distributions from the usual place: https://golang.org/dl/#go1.16rc1

To find out what has changed in Go 1.16, read the draft release notes: https://tip.golang.org/doc/go1.16

Source: https://groups.google.com/g/golang-announce/c/U_FUHY4wuSc/m/3_Vw3oqpAgAJ

Hello 👋 Recently I've stumbled upon the blog post about //go:embed directive usage: a new feature introduced in Go 1.16,

>> that allows you to include the contents of arbitrary files and directories in your Go application.

Looks quite interesting, have a look:
https://blog.carlmjohnson.net/post/2021/how-to-use-go-embed/

Generic programming proposal has got accepted ✅

https://github.com/golang/go/issues/43651

The Go Wiki includes a slice trick on filtering slices without allocating.

filtered := items[:0]
for _, x := range items {
if condition(x) {
filtered = append(filtered, x)
}
}

This post will attempt to explain how that works: https://abhinavg.net/posts/zero-alloc-slice-filter/

How to work with context.Context: an official blog post.

The documentation for context states:

“Contexts should not be stored inside a struct type, but instead passed to each function that needs it.”

This article expands on that advice with reasons and examples describing why it's important to pass Context rather than store it in another type.

https://blog.golang.org/context-and-structs

Introduction to generics from “Learn Go with tests”: A nice tutorial that takes a step approach to teach generics starting from duplicating code for types, then to interface{}, and finally to generics. And you can run it all in the go2go playground.

https://quii.gitbook.io/learn-go-with-tests/meta/intro-to-generics

A lot of projects use gRPC framework nowadays to build an efficient cross-service communication layer., and usually the calls between services are fast, frequent, and expected to have low latencies.

But what if we have a bit different problem to solve, e.g. handling long-lived streams?

In this article Omri Cohen walk us through an excellent tutorial about how to design gRPC long-lived streaming. Take a look: https://dev.bitolog.com/grpc-long-lived-streaming/

You may be wondering how to...
https://pmihaylov.com/vim-for-go-development/ 🙂

Between Go and Elixir

"Reason wanted me to make a choice, and I am so glad I didn’t. Because the more I kept delving into both Elixir and Go, the more I found out how complementary the two can be to one another."
https://preslav.me/2021/04/23/between-golang-and-elixir/

Top 5 Lessons I learned while working with Go for two years.

In the article, Sayed Alesawy is sharing some of the mistakes and the lessons they faced by doing GoLang development for 2 years:

“ I have been writing Go services for like two years now, both professionally and as personal projects. Using a certain language in numerous projects over an extended period of time allows you to make mistakes, fix them, realize it's still not the best way to do it, fix them again and generally get better the more you get to re-do stuff because each time you try to avoid a mistake you made the last time that caused you a headache throughout that project.”

TLDR;

1. Take the Go highway to Concurrency
2. If it can be singleton, then make it singleton, but do it right!
3. Beware of Blocking Code
4. Graceful Termination and Clean Up
5. Go Modules FTW.

Read more at:
https://sayedalesawy.hashnode.dev/top-5-lessons-i-learned-while-working-with-go-for-two-years

Updating the Go Memory Model

The final post in a three-part series that culminates with the outline of a proposal to change Go’s memory model.

Link: https://research.swtch.com/gomm

This post is very technical but the specific changes are clear and accessible. If this proposal is anything like Russ’s previous efforts, be prepared to see changes in Go before long :)

Previous parts of the Memory Models series:
Part 1: Hardware Memory Models;
Part 2: Programming Language Memory Models

Hello, everyone! Here's a great post about what functional options are in Go, and how we can use the options pattern to implement them.

Functional options take the form of extra arguments to a function, that extend or modify its behavior. Here’s an example which uses functional options to create a new House struct:

h := NewHouse(
WithConcrete(),
WithoutFireplace(),
)

Take a look at https://www.sohamkamani.com/golang/options-pattern/

Wondering how to make Ctrl+C safely stop the program in Go? Here’s a short blog post about syscalls handling and cancellation of context.Context:

https://medium.com/@matryer/make-ctrl-c-cancel-the-context-context-bd006a8ad6ff