env.go

// Copyright 2014 Docker authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the DOCKER-LICENSE file.

package docker

import (
	"encoding/json"
	"fmt"
	"io"
	"strconv"
	"strings"
)

type Env []string

func (env *Env) Get(key string) (value string) {
	return env.Map()[key]
}

func (env *Env) Exists(key string) bool {
	_, exists := env.Map()[key]
	return exists
}

func (env *Env) GetBool(key string) (value bool) {
	s := strings.ToLower(strings.Trim(env.Get(key), " \t"))
	if s == "" || s == "0" || s == "no" || s == "false" || s == "none" {
		return false
	}
	return true
}

func (env *Env) SetBool(key string, value bool) {
	if value {
		env.Set(key, "1")
	} else {
		env.Set(key, "0")
	}
}

func (env *Env) GetInt(key string) int {
	return int(env.GetInt64(key))
}

func (env *Env) GetInt64(key string) int64 {
	s := strings.Trim(env.Get(key), " \t")
	val, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		return -1
	}
	return val
}

func (env *Env) SetInt(key string, value int) {
	env.Set(key, fmt.Sprintf("%d", value))
}

func (env *Env) SetInt64(key string, value int64) {
	env.Set(key, fmt.Sprintf("%d", value))
}

func (env *Env) GetList(key string) []string {
	sval := env.Get(key)
	if sval == "" {
		return nil
	}
	l := make([]string, 0, 1)
	if err := json.Unmarshal([]byte(sval), &l); err != nil {
		l = append(l, sval)
	}
	return l
}

func (env *Env) GetJson(key string, iface interface{}) error {
	sval := env.Get(key)
	if sval == "" {
		return nil
	}
	return json.Unmarshal([]byte(sval), iface)
}

func (env *Env) SetJson(key string, value interface{}) error {
	sval, err := json.Marshal(value)
	if err != nil {
		return err
	}
	env.Set(key, string(sval))
	return nil
}

func (env *Env) SetList(key string, value []string) error {
	return env.SetJson(key, value)
}

func (env *Env) Set(key, value string) {
	*env = append(*env, key+"="+value)
}

// Decode decodes `src` as a json dictionary, and adds each decoded key-value
// pair to the environment.
//
// If `src` cannot be decoded as a json dictionary, an error is returned.
func (env *Env) Decode(src io.Reader) error {
	m := make(map[string]interface{})
	if err := json.NewDecoder(src).Decode(&m); err != nil {
		return err
	}
	for k, v := range m {
		env.SetAuto(k, v)
	}
	return nil
}

func (env *Env) SetAuto(k string, v interface{}) {
	if fval, ok := v.(float64); ok {
		env.SetInt64(k, int64(fval))
	} else if sval, ok := v.(string); ok {
		env.Set(k, sval)
	} else if val, err := json.Marshal(v); err == nil {
		env.Set(k, string(val))
	} else {
		env.Set(k, fmt.Sprintf("%v", v))
	}
}

func (env *Env) Map() map[string]string {
	m := make(map[string]string)
	for _, kv := range *env {
		parts := strings.SplitN(kv, "=", 2)
		m[parts[0]] = parts[1]
	}
	return m
}