From f93a10f9278583b5a3b895bb12b69b1803d8d6d9 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Mon, 16 Oct 2023 23:27:40 +0300
Subject: [PATCH] [knf/validators/network] Added 'HasIP' validator

---
 CHANGELOG.md                              |  1 +
 knf/validators/network/validators.go      | 39 +++++++++++++++++++++--
 knf/validators/network/validators_test.go | 22 +++++++++++++
 3 files changed, 59 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 59578fa7..8e8092e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ### 12.81.0
 
+* `[knf/validators/network]` Added `HasIP` validator
 * `[strutil]` Added method `ReplaceIgnoreCase`
 * `[uuid]` `GenUUID4` renamed to `UUID4`
 * `[uuid]` `GenUUID5` renamed to `UUID5`
diff --git a/knf/validators/network/validators.go b/knf/validators/network/validators.go
index 80713ba5..34c9522b 100644
--- a/knf/validators/network/validators.go
+++ b/knf/validators/network/validators.go
@@ -33,6 +33,9 @@ var (
 
 	// URL returns error if config property isn't a valid URL
 	URL = validateURL
+
+	// HasIP returns error if system doesn't have interface with IP from config property
+	HasIP = validateHasIP
 )
 
 // ////////////////////////////////////////////////////////////////////////////////// //
@@ -82,7 +85,7 @@ func validateMAC(config *knf.Config, prop string, value any) error {
 		return fmt.Errorf("%s is not a valid MAC address: %v", macStr, err)
 	}
 
-	return err
+	return nil
 }
 
 func validateCIDR(config *knf.Config, prop string, value any) error {
@@ -98,7 +101,7 @@ func validateCIDR(config *knf.Config, prop string, value any) error {
 		return fmt.Errorf("%s is not a valid CIDR address: %v", cidrStr, err)
 	}
 
-	return err
+	return nil
 }
 
 func validateURL(config *knf.Config, prop string, value any) error {
@@ -114,5 +117,35 @@ func validateURL(config *knf.Config, prop string, value any) error {
 		return fmt.Errorf("%s is not a valid URL address: %v", urlStr, err)
 	}
 
-	return err
+	return nil
+}
+
+func validateHasIP(config *knf.Config, prop string, value any) error {
+	ipStr := config.GetS(prop)
+
+	if ipStr == "" {
+		return nil
+	}
+
+	interfaces, err := net.Interfaces()
+
+	if err != nil {
+		return fmt.Errorf("Can't get interfaces info for check: %v", err)
+	}
+
+	for _, i := range interfaces {
+		addr, err := i.Addrs()
+
+		if err != nil {
+			continue
+		}
+
+		for _, a := range addr {
+			if ipStr == a.(*net.IPNet).IP.String() {
+				return nil
+			}
+		}
+	}
+
+	return fmt.Errorf("The system does not have an interface with the address %s", ipStr)
 }
diff --git a/knf/validators/network/validators_test.go b/knf/validators/network/validators_test.go
index 5729b20a..802c0926 100644
--- a/knf/validators/network/validators_test.go
+++ b/knf/validators/network/validators_test.go
@@ -23,6 +23,7 @@ const _CONFIG_DATA = `
 	test0:
 	test1: 127.0.0.1
 	test2: 300.0.400.5
+	test3: 192.168.1.254
 
 [port]
 	test0:
@@ -83,6 +84,27 @@ func (s *ValidatorSuite) TestIPValidator(c *C) {
 	c.Assert(errs[0].Error(), Equals, "300.0.400.5 is not a valid IP address")
 }
 
+func (s *ValidatorSuite) TestHasIPValidator(c *C) {
+	configFile := createConfig(c, _CONFIG_DATA)
+
+	err := knf.Global(configFile)
+	c.Assert(err, IsNil)
+
+	errs := knf.Validate([]*knf.Validator{
+		{"ip:test0", HasIP, nil},
+		{"ip:test1", HasIP, nil},
+	})
+
+	c.Assert(errs, HasLen, 0)
+
+	errs = knf.Validate([]*knf.Validator{
+		{"ip:test3", HasIP, nil},
+	})
+
+	c.Assert(errs, HasLen, 1)
+	c.Assert(errs[0].Error(), Equals, "The system does not have an interface with the address 192.168.1.254")
+}
+
 func (s *ValidatorSuite) TestPortValidator(c *C) {
 	configFile := createConfig(c, _CONFIG_DATA)