lang: funcs: Add cidr_to_ip function

lang/funcs/core/net/cidr_to_ip_func.go

@@ -0,0 +1,45 @@
+// Mgmt
+// Copyright (C) 2013-2020+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package corenet
+
+import (
+	"net"
+	"strings"
+
+	"github.com/purpleidea/mgmt/lang/funcs/simple"
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+func init() {
+	simple.ModuleRegister(ModuleName, "cidr_to_ip", &types.FuncValue{
+		T: types.NewType("func(a str) str"),
+		V: CidrToIP,
+	})
+}
+
+// CidrToIP returns the IP from a CIDR address
+func CidrToIP(input []types.Value) (types.Value, error) {
+	cidr := input[0].Str()
+	ip, _, err := net.ParseCIDR(strings.TrimSpace(cidr))
+	if err != nil {
+		return &types.StrValue{}, err
+	}
+	return &types.StrValue{
+		V: ip.String(),
+	}, nil
+}

lang/funcs/core/net/cidr_to_ip_func_test.go

@@ -0,0 +1,71 @@
+// Mgmt
+// Copyright (C) 2013-2020+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package corenet
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+func TestCidrToIP(t *testing.T) {
+	cidrtests := []struct {
+		name     string
+		input    string
+		expected string
+		err      error
+	}{
+		// IPv4 success.
+		{"IPv4 cidr", "192.0.2.12/24", "192.0.2.12", nil},
+		{"spaced IPv4 cidr ", "  192.168.42.13/24  ", "192.168.42.13", nil},
+
+		//IPv4 failure - tests error.
+		{"invalid IPv4 cidr", "192.168.42.13/33", "", fmt.Errorf("invalid CIDR address: 192.168.42.13/33")},
+
+		// IPV6 success.
+		{"IPv6 cidr", "2001:db8::/32", "2001:db8::", nil},
+		{"spaced IPv6 cidr ", "   2001:db8::/32   ", "2001:db8::", nil},
+
+		// IPv6 failure - tests error.
+		{"invalid IPv6 cidr", "2001:db8::/333", "", fmt.Errorf("invalid CIDR address: 2001:db8::/333")},
+	}
+
+	for _, ts := range cidrtests {
+		test := ts
+		t.Run(test.name, func(t *testing.T) {
+			output, err := CidrToIP([]types.Value{&types.StrValue{V: test.input}})
+			expectedStr := &types.StrValue{V: test.expected}
+
+			if test.err != nil && err.Error() != test.err.Error() {
+				t.Errorf("input: %s, expected error: %q, got: %q", test.input, test.err, err)
+				return
+			} else if test.err != nil && err == nil {
+				t.Errorf("input: %s, expected error: %v, but got nil", test.input, test.err)
+				return
+			} else if test.err == nil && err != nil {
+				t.Errorf("input: %s, did not expect error but got: %#v", test.input, err)
+				return
+			}
+			if err1 := output.Cmp(expectedStr); err1 != nil {
+				t.Errorf("input: %s, expected: %s, got: %s", test.input, expectedStr, output)
+				return
+			}
+		})
+	}
+}