moby/opts/env.go
Brian Goff ebcb7d6b40 Remove string checking in API error handling
Use strongly typed errors to set HTTP status codes.
Error interfaces are defined in the api/errors package and errors
returned from controllers are checked against these interfaces.

Errors can be wraeped in a pkg/errors.Causer, as long as somewhere in the
line of causes one of the interfaces is implemented. The special error
interfaces take precedence over Causer, meaning if both Causer and one
of the new error interfaces are implemented, the Causer is not
traversed.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2017-08-15 16:01:11 -04:00

48 lines
1.1 KiB
Go

package opts
import (
"fmt"
"os"
"runtime"
"strings"
"github.com/pkg/errors"
)
// 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 "", errors.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
}