kelseyhightower/envconfig VS koanf

To configure the app I'd take a look at https://github.com/kelseyhightower/envconfig

envconfig

- Having one way of configuring the app is excellent. You can either prefer environment variables, a file, or flags. You can do what Viper does by reading the file and unmarshalling it. The built-in flag package is enough for your flag-based config needs. If you want to prefer environment variables, I prefer https://github.com/kelseyhightower/envconfig

To extract values from the system environment, I utilize envconfig, a Go package. Envconfig facilitates mapping system environment variables to a Go struct. These Go structs are exposed through a config package, enabling other parts of the application to access them.

You could prefix your env vars and use this package. https://github.com/kelseyhightower/envconfig

kelseyhightower/envconfig

Pretty much all of our services and pkgs use https://github.com/kelseyhightower/envconfig. It’s dead simple, gets out of your way, and is battle tested

https://github.com/kelseyhightower/envconfig (read config from environment variables, more succinct than viper)

LINK: https://github.com/knadh/koanf

For configuration, I like Koanf.

Of course. You should always use a good config package. caarlos0/env is okay but https://github.com/knadh/koanf is a better all around solution imo.

You can also use Viper with urfave/cli, or you can replace Viper with knadh/koanf, which I personally prefer.

Use viper with care. It has some dangerous fundamental flaws [1]. We got bitten hard, submitted a PR [2] and followed up for a year and a half to no avail, before I went ahead and reinvented the wheel and wrote koanf (plug), specifically to avoid viper's flaws.

Most importantly:

- Breaks JSON, YAML, TOML etc. language specs by forcibly lowercasing all keys internally. Dangerous because it can silently merge differently cased config keys into lowercase.

- Hard codes big unnecessary dependencies into the core, significantly bloating build sizes. No separation or abstraction.

[1] https://github.com/spf13/viper/pull/635

[2] https://github.com/knadh/koanf#alternative-to-viper

It's not hard to a) look for a key in an environment variable b) accept a key as a parameter c) load a key from a file d) all of the above with something like koanf

Came across this the other day https://github.com/knadh/koanf as an alternative to Viper.

https://github.com/knadh/koanf for config management. Readme contains why it's a good alternative to viper.