[pull] master from Netflix:master

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: Go
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: 1.22
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Test
+      run: go test -v ./...

README.md

@@ -1,7 +1,7 @@
 # go-env
 
-[![Build Status](https://travis-ci.org/Netflix/go-env.svg?branch=master)](https://travis-ci.org/Netflix/go-env)
-[![GoDoc](https://godoc.org/github.com/Netflix/go-env?status.svg)](https://godoc.org/github.com/Netflix/go-env)
+![Build Status](https://github.com/Netflix/go-env/actions/workflows/build.yml/badge.svg)
+[![Go Reference](https://pkg.go.dev/badge/github.com/Netflix/go-env.svg)](https://pkg.go.dev/github.com/Netflix/go-env)
 [![NetflixOSS Lifecycle](https://img.shields.io/osslifecycle/Netflix/go-expect.svg)]()
 
 
@@ -14,8 +14,9 @@ package main
 
 import (
 	"log"
+	"time"
 
-	env "github.com/Netflix/go-env"
+	"github.com/Netflix/go-env"
 )
 
 type Environment struct {
@@ -32,6 +33,11 @@ type Environment struct {
 	}
 
 	Extras env.EnvSet
+
+	Duration      time.Duration `env:"TYPE_DURATION"`
+	DefaultValue  string        `env:"MISSING_VAR,default=default_value"`
+	RequiredValue string        `env:"IM_REQUIRED,required=true"`
+	ArrayValue    []string      `env:"ARRAY_VALUE,default=value1|value2|value3"`
 }
 
 func main() {
@@ -45,7 +51,7 @@ func main() {
 
 	// ...
 
-	es, err = env.Marshal(environment)
+	es, err = env.Marshal(&environment)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -59,11 +65,79 @@ func main() {
 	es.Apply(cs)
 
 	environment = Environment{}
-	err = env.Unmarshal(es, &environment)
-	if err != nil {
+	if err = env.Unmarshal(es, &environment); err != nil {
 		log.Fatal(err)
 	}
 
 	environment.Extras = es
 }
 ```
+
+This will initially throw an error if `IM_REQUIRED` is not set in the environment as part of the env struct validation.
+
+This error can be resolved by setting the `IM_REQUIRED` environment variable manually in the environment or by setting it in the 
+code prior to calling `UnmarshalFromEnviron` with:
+```go
+os.Setenv("IM_REQUIRED", "some_value")
+```
+
+## Custom Marshaler/Unmarshaler
+
+There is limited support for dictating how a field should be marshaled or unmarshaled. The following example
+shows how you could marshal/unmarshal from JSON
+
+```go
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+
+	"github.com/Netflix/go-env"
+)
+
+type SomeData struct {
+    SomeField int `json:"someField"`
+}
+
+func (s *SomeData) UnmarshalEnvironmentValue(data string) error {
+    var tmp SomeData
+	if  err := json.Unmarshal([]byte(data), &tmp); err != nil {
+		return err
+	}
+	*s = tmp 
+	return nil
+}
+
+func (s SomeData) MarshalEnvironmentValue() (string, error) {
+	bytes, err := json.Marshal(s)
+	if err != nil {
+		return "", err
+	}
+	return string(bytes), nil
+}
+
+type Config struct {
+    SomeData *SomeData `env:"SOME_DATA"`
+}
+
+func main() {
+	var cfg Config
+	if _, err := env.UnmarshalFromEnviron(&cfg); err != nil {
+		log.Fatal(err)
+	}
+
+    if cfg.SomeData != nil && cfg.SomeData.SomeField == 42 {
+        fmt.Println("Got 42!")
+    } else {
+        fmt.Printf("Got nil or some other value: %v\n", cfg.SomeData)
+    }
+
+    es, err := env.Marshal(&cfg)
+	if err != nil {
+		log.Fatal(err)
+	}
+    fmt.Printf("Got the following: %+v\n", es)
+}
+```