powerman · powerman · Dec 16, 2020 · Dec 16, 2020
diff --git a/gen.values_impl.go b/gen.values_impl.go
@@ -434,3 +434,36 @@ func (v *ListenPort) Get() interface{} {
 func (v *ListenPort) Type() string {
 	return "ListenPort"
 }
+
+
+var _ Value = &IPNet{}
+
+// String implements flag.Value interface.
+func (v *IPNet) String() string {
+	if v == nil || v.value == nil {
+		return ""
+	}
+	return fmt.Sprint(*v.value)
+}
+
+// Set implements flag.Value interface.
+func (v *IPNet) Set(s string) error {
+	err := v.set(s)
+	if err != nil {
+		v.value = nil
+	}
+	return err
+}
+
+// Get implements flag.Getter interface.
+func (v *IPNet) Get() interface{} {
+	if v.value == nil {
+		return nil
+	}
+	return *v.value
+}
+
+// Type implements pflag.Value interface.
+func (v *IPNet) Type() string {
+	return "IPNet"
+}
diff --git a/gen.values_must.go b/gen.values_must.go
@@ -124,3 +124,14 @@ func MustListenPort(s string) ListenPort {
 	}
 	return v
 }
+
+
+// MustIPNet returns IPNet initialized with given value or panics.
+func MustIPNet(s string) IPNet {
+	var v IPNet
+	err := v.Set(s)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
diff --git a/values.go b/values.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"net"
 	"net/url"
 	"strconv"
 	"strings"
@@ -212,3 +213,15 @@ func (v *ListenPort) set(s string) error {
 	v.value = &i
 	return nil
 }
+
+// IPNet can be set to CIDR address.
+type IPNet struct{ value **net.IPNet }
+
+func (v *IPNet) set(s string) error {
+	_, ipNet, err := net.ParseCIDR(s)
+	if err != nil {
+		return err
+	}
+	v.value = &ipNet
+	return nil
+}
diff --git a/values_custom.go b/values_custom.go
@@ -1,6 +1,9 @@
 package appcfg
 
-import "time"
+import (
+	"net"
+	"time"
+)
 
 // Value is like Get except it returns zero value and set *err to
 // RequiredError if unset.
@@ -91,3 +94,13 @@ func MustIntBetween(s string, min, max int) IntBetween {
 	}
 	return v
 }
+
+// Value is like Get except it returns zero value and set *err to
+// RequiredError if unset.
+func (v *IPNet) Value(err *error) (val *net.IPNet) { //nolint:gocritic // ptrToRefParam.
+	if v.value == nil {
+		*err = &RequiredError{v}
+		return val
+	}
+	return *v.value
+}
diff --git a/values_impl.go b/values_impl.go
@@ -1,4 +1,4 @@
-//go:generate gobin -m -run github.com/cheekybits/genny -in=$GOFILE -out=gen.$GOFILE gen "Duration=Bool,String,NotEmptyString,OneOfString,Endpoint,Int,Int64,Uint,Uint64,Float64,IntBetween,Port,ListenPort"
+//go:generate gobin -m -run github.com/cheekybits/genny -in=$GOFILE -out=gen.$GOFILE gen "Duration=Bool,String,NotEmptyString,OneOfString,Endpoint,Int,Int64,Uint,Uint64,Float64,IntBetween,Port,ListenPort,IPNet"
 //go:generate sed -i -e "\\,^//go:generate,d" gen.$GOFILE
 
 package appcfg

diff --git a/values_must.go b/values_must.go
@@ -1,4 +1,4 @@
-//go:generate gobin -m -run github.com/cheekybits/genny -in=$GOFILE -out=gen.$GOFILE gen "Duration=Bool,String,NotEmptyString,Endpoint,Int,Int64,Uint,Uint64,Float64,Port,ListenPort"
+//go:generate gobin -m -run github.com/cheekybits/genny -in=$GOFILE -out=gen.$GOFILE gen "Duration=Bool,String,NotEmptyString,Endpoint,Int,Int64,Uint,Uint64,Float64,Port,ListenPort,IPNet"
 //go:generate sed -i -e "\\,^//go:generate,d" gen.$GOFILE
 
 package appcfg

diff --git a/values_test.go b/values_test.go
@@ -104,3 +104,35 @@ func TestUint(tt *testing.T) {
 	t.PanicMatch(func() { v = appcfg.MustUint("") }, "invalid")
 	t.PanicMatch(func() { v = appcfg.MustUint("-1") }, "invalid")
 }
+
+func TestIPNet(tt *testing.T) {
+	t := check.T(tt)
+	t.Parallel()
+
+	var v appcfg.IPNet
+	t.Equal(v.Type(), "IPNet")
+
+	t.Equal(v.String(), "")
+	t.Nil(v.Get())
+	var err error
+	t.Zero(v.Value(&err))
+	t.Match(err, "required")
+
+	t.Nil(v.Set("0.0.0.0/0"))
+
+	t.Equal(v.String(), "0.0.0.0/0")
+	t.NotNil(v.Get())
+	err = nil
+	t.NotZero(v.Value(&err))
+	t.Nil(err)
+
+	v = appcfg.MustIPNet("192.168.2.1/24")
+
+	t.Equal(v.String(), "192.168.2.0/24")
+	t.NotNil(v.Get())
+	err = nil
+	t.Equal(v.Value(&err).String(), "192.168.2.0/24")
+	t.Nil(err)
+
+	t.PanicMatch(func() { v = appcfg.MustIPNet("") }, "invalid")
+}