minio/pkg/env/env.go

101 lines
2.4 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package env
import (
"strconv"
"strings"
"sync"
)
var (
privateMutex sync.RWMutex
lockEnvMutex sync.Mutex
envOff bool
)
// LockSetEnv locks modifications to environment.
// Call returned function to unlock.
func LockSetEnv() func() {
lockEnvMutex.Lock()
return lockEnvMutex.Unlock
}
// SetEnvOff - turns off env lookup
// A global lock above this MUST ensure that
func SetEnvOff() {
privateMutex.Lock()
defer privateMutex.Unlock()
envOff = true
}
// SetEnvOn - turns on env lookup
func SetEnvOn() {
privateMutex.Lock()
defer privateMutex.Unlock()
envOff = false
}
// IsSet returns if the given env key is set.
func IsSet(key string) bool {
_, _, _, ok := LookupEnv(key)
return ok
}
// Get retrieves the value of the environment variable named
// by the key. If the variable is present in the environment the
// value (which may be empty) is returned. Otherwise it returns
// the specified default value.
func Get(key, defaultValue string) string {
privateMutex.RLock()
ok := envOff
privateMutex.RUnlock()
if ok {
return defaultValue
}
if v, _, _, ok := LookupEnv(key); ok {
return v
}
return defaultValue
}
// GetInt returns an integer if found in the environment
// and returns the default value otherwise.
func GetInt(key string, defaultValue int) (int, error) {
v := Get(key, "")
if v == "" {
return defaultValue, nil
}
return strconv.Atoi(v)
}
// List all envs with a given prefix.
func List(prefix string) (envs []string) {
for _, env := range Environ() {
if strings.HasPrefix(env, prefix) {
values := strings.SplitN(env, "=", 2)
if len(values) == 2 {
envs = append(envs, values[0])
}
}
}
return envs
}