adding code

2016-07-01 09:35:21 -07:00
parent 9a214781b4
commit 73aec0c514
191 changed files with 45923 additions and 0 deletions
@@ -0,0 +1,19 @@
+Copyright (c) 2013 Kelsey Hightower
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
@@ -0,0 +1,2 @@
+Kelsey Hightower kelsey.hightower@gmail.com github.com/kelseyhightower
+Travis Parker    travis.parker@gmail.com    github.com/teepark
@@ -0,0 +1,161 @@
+# envconfig
+
+[![Build Status](https://travis-ci.org/kelseyhightower/envconfig.png)](https://travis-ci.org/kelseyhightower/envconfig)
+
+```Go
+import "github.com/kelseyhightower/envconfig"
+```
+
+## Documentation
+
+See [godoc](http://godoc.org/github.com/kelseyhightower/envconfig)
+
+## Usage
+
+Set some environment variables:
+
+```Bash
+export MYAPP_DEBUG=false
+export MYAPP_PORT=8080
+export MYAPP_USER=Kelsey
+export MYAPP_RATE="0.5"
+export MYAPP_TIMEOUT="3m"
+export MYAPP_USERS="rob,ken,robert"
+```
+
+Write some code:
+
+```Go
+package main
+
+import (
+    "fmt"
+    "log"
+    "time"
+
+    "github.com/kelseyhightower/envconfig"
+)
+
+type Specification struct {
+    Debug   bool
+    Port    int
+    User    string
+    Users   []string
+    Rate    float32
+    Timeout time.Duration
+}
+
+func main() {
+    var s Specification
+    err := envconfig.Process("myapp", &s)
+    if err != nil {
+        log.Fatal(err.Error())
+    }
+    format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nTimeout: %s\n"
+    _, err = fmt.Printf(format, s.Debug, s.Port, s.User, s.Rate)
+    if err != nil {
+        log.Fatal(err.Error())
+    }
+
+    fmt.Println("Users:")
+    for _, u := range s.Users {
+        fmt.Printf("  %s\n", u)
+    }
+}
+```
+
+Results:
+
+```Bash
+Debug: false
+Port: 8080
+User: Kelsey
+Rate: 0.500000
+Timeout: 3m0s
+Users:
+  rob
+  ken
+  robert
+```
+
+## Struct Tag Support
+
+Envconfig supports the use of struct tags to specify alternate, default, and required
+environment variables.
+
+For example, consider the following struct:
+
+```Go
+type Specification struct {
+    MultiWordVar string `envconfig:"multi_word_var"`
+    DefaultVar   string `default:"foobar"`
+    RequiredVar  string `required:"true"`
+    IgnoredVar   string `ignored:"true"`
+}
+```
+
+Envconfig will process value for `MultiWordVar` by populating it with the
+value for `MYAPP_MULTI_WORD_VAR`.
+
+```Bash
+export MYAPP_MULTI_WORD_VAR="this will be the value"
+
+# export MYAPP_MULTIWORDVAR="and this will not"
+```
+
+If envconfig can't find an environment variable value for `MYAPP_DEFAULTVAR`,
+it will populate it with "foobar" as a default value.
+
+If envconfig can't find an environment variable value for `MYAPP_REQUIREDVAR`,
+it will return an error when asked to process the struct.
+
+If envconfig can't find an environment variable in the form `PREFIX_MYVAR`, and there
+is a struct tag defined, it will try to populate your variable with an environment
+variable that directly matches the envconfig tag in your struct definition:
+
+```shell
+export SERVICE_HOST=127.0.0.1
+export MYAPP_DEBUG=true
+```
+```Go
+type Specification struct {
+    ServiceHost string `envconfig:"SERVICE_HOST"`
+    Debug       bool
+}
+```
+
+Envconfig won't process a field with the "ignored" tag set to "true", even if a corresponding
+environment variable is set.
+
+## Supported Struct Field Types
+
+envconfig supports supports these struct field types:
+
+  * string
+  * int8, int16, int32, int64
+  * bool
+  * float32, float64
+
+Embedded structs using these fields are also supported.
+
+## Custom Decoders
+
+Any field whose type (or pointer-to-type) implements `envconfig.Decoder` can
+control its own deserialization:
+
+```Bash
+export DNS_SERVER=8.8.8.8
+```
+
+```Go
+type IPDecoder net.IP
+
+func (ipd *IPDecoder) Decode(value string) error {
+    *ipd = IPDecoder(net.ParseIP(value))
+    return nil
+}
+
+type DNSConfig struct {
+    Address IPDecoder `envconfig:"DNS_SERVER"`
+}
+```
@@ -0,0 +1,8 @@
+// Copyright (c) 2013 Kelsey Hightower. All rights reserved.
+// Use of this source code is governed by the MIT License that can be found in
+// the LICENSE file.
+
+// Package envconfig implements decoding of environment variables based on a user
+// defined specification. A typical use is using environment variables for
+// configuration settings.
+package envconfig
@@ -0,0 +1,193 @@
+// Copyright (c) 2013 Kelsey Hightower. All rights reserved.
+// Use of this source code is governed by the MIT License that can be found in
+// the LICENSE file.
+
+package envconfig
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+)
+
+// ErrInvalidSpecification indicates that a specification is of the wrong type.
+var ErrInvalidSpecification = errors.New("specification must be a struct pointer")
+
+// A ParseError occurs when an environment variable cannot be converted to
+// the type required by a struct field during assignment.
+type ParseError struct {
+	KeyName   string
+	FieldName string
+	TypeName  string
+	Value     string
+}
+
+// A Decoder is a type that knows how to de-serialize environment variables
+// into itself.
+type Decoder interface {
+	Decode(value string) error
+}
+
+func (e *ParseError) Error() string {
+	return fmt.Sprintf("envconfig.Process: assigning %[1]s to %[2]s: converting '%[3]s' to type %[4]s", e.KeyName, e.FieldName, e.Value, e.TypeName)
+}
+
+// Process populates the specified struct based on environment variables
+func Process(prefix string, spec interface{}) error {
+	s := reflect.ValueOf(spec)
+
+	if s.Kind() != reflect.Ptr {
+		return ErrInvalidSpecification
+	}
+	s = s.Elem()
+	if s.Kind() != reflect.Struct {
+		return ErrInvalidSpecification
+	}
+	typeOfSpec := s.Type()
+	for i := 0; i < s.NumField(); i++ {
+		f := s.Field(i)
+		if !f.CanSet() || typeOfSpec.Field(i).Tag.Get("ignored") == "true" {
+			continue
+		}
+
+		if typeOfSpec.Field(i).Anonymous && f.Kind() == reflect.Struct {
+			embeddedPtr := f.Addr().Interface()
+			if err := Process(prefix, embeddedPtr); err != nil {
+				return err
+			}
+			f.Set(reflect.ValueOf(embeddedPtr).Elem())
+		}
+
+		alt := typeOfSpec.Field(i).Tag.Get("envconfig")
+		fieldName := typeOfSpec.Field(i).Name
+		if alt != "" {
+			fieldName = alt
+		}
+		key := strings.ToUpper(fmt.Sprintf("%s_%s", prefix, fieldName))
+		// `os.Getenv` cannot differentiate between an explicitly set empty value
+		// and an unset value. `os.LookupEnv` is preferred to `syscall.Getenv`,
+		// but it is only available in go1.5 or newer.
+		value, ok := syscall.Getenv(key)
+		if !ok && alt != "" {
+			key := strings.ToUpper(fieldName)
+			value, ok = syscall.Getenv(key)
+		}
+
+		def := typeOfSpec.Field(i).Tag.Get("default")
+		if def != "" && !ok {
+			value = def
+		}
+
+		req := typeOfSpec.Field(i).Tag.Get("required")
+		if !ok && def == "" {
+			if req == "true" {
+				return fmt.Errorf("required key %s missing value", key)
+			}
+			continue
+		}
+
+		err := processField(value, f)
+		if err != nil {
+			return &ParseError{
+				KeyName:   key,
+				FieldName: fieldName,
+				TypeName:  f.Type().String(),
+				Value:     value,
+			}
+		}
+	}
+	return nil
+}
+
+// MustProcess is the same as Process but panics if an error occurs
+func MustProcess(prefix string, spec interface{}) {
+	if err := Process(prefix, spec); err != nil {
+		panic(err)
+	}
+}
+
+func processField(value string, field reflect.Value) error {
+	typ := field.Type()
+
+	decoder := decoderFrom(field)
+	if decoder != nil {
+		return decoder.Decode(value)
+	}
+
+	switch typ.Kind() {
+	case reflect.String:
+		field.SetString(value)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		var (
+			val int64
+			err error
+		)
+		if field.Kind() == reflect.Int64 && typ.PkgPath() == "time" && typ.Name() == "Duration" {
+			var d time.Duration
+			d, err = time.ParseDuration(value)
+			val = int64(d)
+		} else {
+			val, err = strconv.ParseInt(value, 0, typ.Bits())
+		}
+		if err != nil {
+			return err
+		}
+
+		field.SetInt(val)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		val, err := strconv.ParseUint(value, 0, typ.Bits())
+		if err != nil {
+			return err
+		}
+		field.SetUint(val)
+	case reflect.Bool:
+		val, err := strconv.ParseBool(value)
+		if err != nil {
+			return err
+		}
+		field.SetBool(val)
+	case reflect.Float32, reflect.Float64:
+		val, err := strconv.ParseFloat(value, typ.Bits())
+		if err != nil {
+			return err
+		}
+		field.SetFloat(val)
+	case reflect.Slice:
+		vals := strings.Split(value, ",")
+		sl := reflect.MakeSlice(typ, len(vals), len(vals))
+		for i, val := range vals {
+			err := processField(val, sl.Index(i))
+			if err != nil {
+				return err
+			}
+		}
+		field.Set(sl)
+	}
+
+	return nil
+}
+
+func decoderFrom(field reflect.Value) Decoder {
+	if field.CanInterface() {
+		dec, ok := field.Interface().(Decoder)
+		if ok {
+			return dec
+		}
+	}
+
+	// also check if pointer-to-type implements Decoder,
+	// and we can get a pointer to our field
+	if field.CanAddr() {
+		field = field.Addr()
+		dec, ok := field.Interface().(Decoder)
+		if ok {
+			return dec
+		}
+	}
+
+	return nil
+}