minio/pkg/env/env.go

101 lines
2.2 KiB
Go

/*
* MinIO Cloud Storage, (C) 2019-2020 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
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
}