github.com/demonoid81/moby@v0.0.0-20200517203328-62dd8e17c460/opts/ip.go (about) 1 package opts // import "github.com/demonoid81/moby/opts" 2 3 import ( 4 "fmt" 5 "net" 6 ) 7 8 // IPOpt holds an IP. It is used to store values from CLI flags. 9 type IPOpt struct { 10 *net.IP 11 } 12 13 // NewIPOpt creates a new IPOpt from a reference net.IP and a 14 // string representation of an IP. If the string is not a valid 15 // IP it will fallback to the specified reference. 16 func NewIPOpt(ref *net.IP, defaultVal string) *IPOpt { 17 o := &IPOpt{ 18 IP: ref, 19 } 20 o.Set(defaultVal) 21 return o 22 } 23 24 // Set sets an IPv4 or IPv6 address from a given string. If the given 25 // string is not parsable as an IP address it returns an error. 26 func (o *IPOpt) Set(val string) error { 27 ip := net.ParseIP(val) 28 if ip == nil { 29 return fmt.Errorf("%s is not an ip address", val) 30 } 31 *o.IP = ip 32 return nil 33 } 34 35 // String returns the IP address stored in the IPOpt. If stored IP is a 36 // nil pointer, it returns an empty string. 37 func (o *IPOpt) String() string { 38 if *o.IP == nil { 39 return "" 40 } 41 return o.IP.String() 42 } 43 44 // Type returns the type of the option 45 func (o *IPOpt) Type() string { 46 return "ip" 47 }