traefik/vendor/github.com/docker/cli/opts/env.go
2018-01-22 12:16:03 +01:00

46 lines
1.1 KiB
Go

package opts
import (
"fmt"
"os"
"runtime"
"strings"
)
// ValidateEnv validates an environment variable and returns it.
// If no value is specified, it returns the current value using os.Getenv.
//
// As on ParseEnvFile and related to #16585, environment variable names
// are not validate what so ever, it's up to application inside docker
// to validate them or not.
//
// The only validation here is to check if name is empty, per #25099
func ValidateEnv(val string) (string, error) {
arr := strings.Split(val, "=")
if arr[0] == "" {
return "", fmt.Errorf("invalid environment variable: %s", val)
}
if len(arr) > 1 {
return val, nil
}
if !doesEnvExist(val) {
return val, nil
}
return fmt.Sprintf("%s=%s", val, os.Getenv(val)), nil
}
func doesEnvExist(name string) bool {
for _, entry := range os.Environ() {
parts := strings.SplitN(entry, "=", 2)
if runtime.GOOS == "windows" {
// Environment variable are case-insensitive on Windows. PaTh, path and PATH are equivalent.
if strings.EqualFold(parts[0], name) {
return true
}
}
if parts[0] == name {
return true
}
}
return false
}