package opts // import "github.com/docker/docker/opts" import ( "fmt" "net" ) // IPOpt holds an IP. It is used to store values from CLI flags. type IPOpt struct { *net.IP } // NewIPOpt creates a new IPOpt from a reference net.IP and a // string representation of an IP. If the string is not a valid // IP it will fallback to the specified reference. func NewIPOpt(ref *net.IP, defaultVal string) *IPOpt { o := &IPOpt{ IP: ref, } o.Set(defaultVal) return o } // Set sets an IPv4 or IPv6 address from a given string. If the given // string is not parsable as an IP address it returns an error. func (o *IPOpt) Set(val string) error { ip := net.ParseIP(val) if ip == nil { return fmt.Errorf("%s is not an ip address", val) } *o.IP = ip return nil } // String returns the IP address stored in the IPOpt. If stored IP is a // nil pointer, it returns an empty string. func (o *IPOpt) String() string { if *o.IP == nil { return "" } return o.IP.String() } // Type returns the type of the option func (o *IPOpt) Type() string { return "ip" }