package opts import ( "os" "strings" "github.com/pkg/errors" ) // ValidateEnv validates an environment variable and returns it. // If no value is specified, it obtains its value from the current environment // // As on ParseEnvFile and related to #16585, environment variable names // are not validated, and it's up to the application inside the container // to validate them or not. // // The only validation here is to check if name is empty, per #25099 func ValidateEnv(val string) (string, error) { k, _, hasValue := strings.Cut(val, "=") if k == "" { return "", errors.New("invalid environment variable: " + val) } if hasValue { // val contains a "=" (but value may be an empty string) return val, nil } if envVal, ok := os.LookupEnv(k); ok { return k + "=" + envVal, nil } return val, nil }