https://github.com/chakradeb/env
A simple golang library to parse environment variables to struct
https://github.com/chakradeb/env
environment-variables golang parser
Last synced: 5 months ago
JSON representation
A simple golang library to parse environment variables to struct
- Host: GitHub
- URL: https://github.com/chakradeb/env
- Owner: chakradeb
- License: mit
- Created: 2020-08-17T21:00:11.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2020-08-19T07:54:43.000Z (almost 6 years ago)
- Last Synced: 2024-01-25T00:13:16.745Z (over 2 years ago)
- Topics: environment-variables, golang, parser
- Language: Go
- Homepage:
- Size: 10.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
Awesome Lists containing this project
README
# Env
[](https://codecov.io/gh/chakradeb/env)
This package helps you to parse environment variables using struct
```go
import "github.com/chakradeb/env"
```
## Examples
Lets start with declaring a couple of environment variables
```shell script
export PORT=5000
export HOST=localhost
export DEBUG=false
```
Now we will write a `struct` to consume these environment variables
```go
type Config struct {
Port int `env:"PORT"`
Host string `env:"HOST"`
Debug bool `env:"DEBUG"`
}
```
Here the tag `env` helps the parser to find the variables from environment variables.
Parser will search for the same name in environment variable as provided by `env` tag.
Now, The main function will look something like this
```go
func main() {
conf := &Config{}
errs := env.Parse(conf)
fmt.Println("Port: ", conf.Port)
fmt.Println("Host: ", conf.Host)
fmt.Println("Debug: ", conf.Debug)
}
```
Result:
```shell script
Port: 5000
Host: localhost
Debug: false
```
## Supported Struct Tags
For now `Env` supports only two kind of tags, `env` and `default`.
Tag `env` is mandatory to match with the environment variable.
Tag `default` is not mandatory but it is useful to set a default value to a struct field.
For example, consider these environment variables:
```shell script
export HOST=localhost
```
Now we will declare some default value to our struct field using the `default` tag
```go
type Config struct {
Port int `env:"PORT" default:"8000"`
Host string `env:"HOST" default:"github.chakradeb.com"`
Debug bool `env:"DEBUG" default:"true"`
}
```
Now we will see the output of our `main` function
```go
func main() {
conf := &Config{}
errs := env.Parse(conf)
fmt.Println("Port: ", conf.Port)
fmt.Println("Host: ", conf.Host)
fmt.Println("Debug: ", conf.Debug)
}
```
Result:
```shell script
Port: 8000
Host: localhost
Debug: true
```
As you can see `Port` and `Debug` has the default value what we've provided using the `default` tag.
But `Host` didn't get the default value provided in the `default` tag,
as it is declared in the environment variable already.
So `default` value will only be effective if there is no environment variable present with the name provided with the `env` tag
## Supported Struct Fields
For now `Env` supports only these struct field types:
- `string`
- `int`
- `int8`
- `int16`
- `int32`
- `int64`
- `float32`
- `float64`
- `bool`
More support will be added soon