cleanenv alternatives and similar packages
Based on the "Configuration" category.
Alternatively, view cleanenv alternatives based on common mentions on social networks and blogs.
-
kelseyhightower/envconfig
Golang library for managing configuration data from environment variables -
env
A simple and zero-dependencies library to parse environment variables into structs. -
koanf
Simple, lightweight, extensible, configuration management library for Go. Support for JSON, TOML, YAML, env, command line, file, S3 etc. Alternative to viper. -
konfig
Composable, observable and performant config handling for Go for the distributed processing era -
confita
Load configuration in cascade from multiple backends into a struct -
gookit/config
📝 Go configuration manage(load,get,set,export). support JSON, YAML, TOML, Properties, INI, HCL, ENV and Flags. Multi file load, data override merge, parse ENV var. Go应用配置加载管理,支持多种格式,多文件加载,远程文件加载,支持数据合并,解析环境变量名 -
GoLobby/Config
A lightweight yet powerful configuration manager for the Go programming language -
config
JSON or YAML configuration wrapper with convenient access methods. -
gcfg
read INI-style configuration files into Go structs; supports user-defined types and subsections -
envconfig
Small library to read your configuration from environment variables -
joshbetz/config
🛠 A configuration library for Go that parses environment variables, JSON files, and reloads automatically on SIGHUP. -
goConfig
goconfig uses a struct as input and populates the fields of this struct with parameters from command line, environment variables and configuration file. -
configuro
An opinionated configuration loading framework for Containerized and Cloud-Native applications. -
configuration
Library for setting values to structs' fields from env, flags, files or default tag -
configure
Configure is a Go package that gives you easy configuration of your project through redundancy -
hocon
go implementation of lightbend's HOCON configuration library https://github.com/lightbend/config -
uConfig
Lightweight, zero-dependency, and extendable configuration management library for Go -
go-up
go-up! A simple configuration library with recursive placeholders resolution and no magic. -
go-ssm-config
Go utility for loading configuration parameters from AWS SSM (Parameter Store) -
CONFLATE
Library providing routines to merge and validate JSON, YAML and/or TOML files -
Genv
Genv is a library for Go (golang) that makes it easy to read and use environment variables in your projects. It also allows environment variables to be loaded from the .env file. -
subVars
Substitute environment variables from command line for template driven configuration files. -
swap
Instantiate/configure structs recursively, based on build environment. (YAML, TOML, JSON and env).
Static code analysis for 29 languages.
Do you think we are missing an alternative of cleanenv or a related project?
Popular Comparisons
README
[Clean Env](logo.svg)
Clean Env
Minimalistic configuration reader
Overview
This is a simple configuration reading tool. It just does the following:
- reads and parses configuration structure from the file
- reads and overwrites configuration structure from environment variables
- writes a detailed variable list to help output
Content
- Installation
- Usage
- Model Format
- Supported types
- Custom Functions
- Supported File Formats
- Integration
- Examples
- Contribution
- Thanks
Installation
To install the package run
go get -u github.com/ilyakaznacheev/cleanenv
Usage
The package is oriented to be simple in use and explicitness.
The main idea is to use a structured configuration variable instead of any sort of dynamic set of configuration fields like some libraries does, to avoid unnecessary type conversions and move the configuration through the program as a simple structure, not as an object with complex behavior.
There are just several actions you can do with this tool and probably only things you want to do with your config if your application is not too complicated.
- read configuration file
- read environment variables
- read some environment variables again
Read Configuration
You can read a configuration file and environment variables in a single function call.
import "github.com/ilyakaznacheev/cleanenv"
type ConfigDatabase struct {
Port string `yaml:"port" env:"PORT" env-default:"5432"`
Host string `yaml:"host" env:"HOST" env-default:"localhost"`
Name string `yaml:"name" env:"NAME" env-default:"postgres"`
User string `yaml:"user" env:"USER" env-default:"user"`
Password string `yaml:"password" env:"PASSWORD"`
}
var cfg ConfigDatabase
err := cleanenv.ReadConfig("config.yml", &cfg)
if err != nil {
...
}
This will do the following:
- parse configuration file according to YAML format (
yaml
tag in this case); - reads environment variables and overwrites values from the file with the values which was found in the environment (
env
tag); - if no value was found on the first two steps, the field will be filled with the default value (
env-default
tag) if it is set.
Read Environment Variables Only
Sometimes you don't want to use configuration files at all, or you may want to use .env
file format instead. Thus, you can limit yourself with only reading environment variables:
import "github.com/ilyakaznacheev/cleanenv"
type ConfigDatabase struct {
Port string `env:"PORT" env-default:"5432"`
Host string `env:"HOST" env-default:"localhost"`
Name string `env:"NAME" env-default:"postgres"`
User string `env:"USER" env-default:"user"`
Password string `env:"PASSWORD"`
}
var cfg ConfigDatabase
err := cleanenv.ReadEnv(&cfg)
if err != nil {
...
}
Update Environment Variables
Some environment variables may change during the application run. To get the new values you need to mark these variables as updatable with the tag env-upd
and then run the update function:
import "github.com/ilyakaznacheev/cleanenv"
type ConfigRemote struct {
Port string `env:"PORT" env-upd`
Host string `env:"HOST" env-upd`
UserName string `env:"USERNAME"`
}
var cfg ConfigRemote
cleanenv.ReadEnv(&cfg)
// ... some actions in-between
err := cleanenv.UpdateEnv(&cfg)
if err != nil {
...
}
Here remote host and port may change in a distributed system architecture. Fields cfg.Port
and cfg.Host
can be updated in the runtime from corresponding environment variables. You can update them before the remote service call. Field cfg.UserName
will not be changed after the initial read, though.
Description
You can get descriptions of all environment variables to use them in the help documentation.
import "github.com/ilyakaznacheev/cleanenv"
type ConfigServer struct {
Port string `env:"PORT" env-description:"server port"`
Host string `env:"HOST" env-description:"server host"`
}
var cfg ConfigRemote
help, err := cleanenv.GetDescription(&cfg, nil)
if err != nil {
...
}
You will get the following:
Environment variables:
PORT server port
HOST server host
Model Format
Library uses tags to configure the model of configuration structure. There are the following tags:
env="<name>"
- environment variable name (e.g.env="PORT"
);env-upd
- flag to mark a field as updatable. RunUpdateEnv(&cfg)
to refresh updatable variables from environment;env-required
- flag to mark a field as required. If set will return an error during environment parsing when the flagged as required field is empty (default Go value). Tagenv-default
is ignored in this case;env-default="<value>"
- default value. If the field wasn't filled from the environment variable default value will be used instead;env-separator="<value>"
- custom list and map separator. If not set, the default separator,
will be used;env-description="<value>"
- environment variable description;env-layout="<value>"
- parsing layout (for types liketime.Time
);env-prefix="<value>"
- prefix for all fields of nested structure (only for nested structures);
Supported types
There are following supported types:
int
(any kind);float
(any kind);string
;boolean
;- slices (of any other supported type);
- maps (of any other supported type);
time.Duration
;time.Time
(layout by default is RFC3339, may be overridden byenv-layout
);*time.Location
(time zone parsing depends on running machine)- any type implementing
cleanenv.Setter
interface.
Custom Functions
To enhance package abilities you can use some custom functions.
Custom Value Setter
To make custom type allows to set the value from the environment variable, you need to implement the Setter
interface on the field level:
type MyField string
func (f *MyField) SetValue(s string) error {
if s == "" {
return fmt.Errorf("field value can't be empty")
}
*f = MyField("my field is: "+ s)
return nil
}
type Config struct {
Field MyField `env="MY_VALUE"`
}
SetValue
method should implement conversion logic from string to custom type.
Custom Value Update
You may need to execute some custom field update logic, e.g. for remote config load.
Thus, you need to implement the Updater
interface on the structure level:
type Config struct {
Field string
}
func (c *Config) Update() error {
newField, err := SomeCustomUpdate()
f.Field = newField
return err
}
Supported File Formats
There are several most popular config file formats supported:
- YAML (
.yaml
,.yml
) - JSON (
.json
) - TOML (
.toml
) - EDN (
.edn
) - ENV (
.env
)
Note:
- while using
.env
file the library will set corresponding data to process environment variables. It will override existing variables with the same keys in the process environment.
Integration
The package can be used with many other solutions. To make it more useful, we made some helpers.
Flag
You can use the cleanenv help together with Golang flag
package.
// create some config structure
var cfg config
// create flag set using `flag` package
fset := flag.NewFlagSet("Example", flag.ContinueOnError)
// get config usage with wrapped flag usage
fset.Usage = cleanenv.FUsage(fset.Output(), &cfg, nil, fset.Usage)
fset.Parse(os.Args[1:])
Examples
type Config struct {
Port string `yaml:"port" env:"PORT" env-default:"8080"`
Host string `yaml:"host" env:"HOST" env-default:"localhost"`
}
var cfg Config
err := ReadConfig("config.yml", &cfg)
if err != nil {
...
}
This code will try to read and parse the configuration file config.yml
as the structure is described in the Config
structure. Then it will overwrite fields from available environment variables (PORT
, HOST
).
For more details check the example directory.
Version Support Policy
We support the last 7 versions of Golang. E.g. if the current version is 1.19, we test compatibility with all versions from 1.19 to 1.13.
If you use an older version of Golang in your project, please use an older library version.
Contribution
The tool is open-sourced under the [MIT](LICENSE) license.
If you will find some error, want to add something or ask a question - feel free to create an issue and/or make a pull request.
Any contribution is welcome.
Thanks
Big thanks to a project kelseyhightower/envconfig for inspiration.
The logo was made by alexchoffy.
Blog Posts
*Note that all licence references and agreements mentioned in the cleanenv README section above
are relevant to that project's source code only.