Add a test around failure case.

MalloZup · May 29, 2018 · 098075a · 098075a
1 parent 7f60d19
commit 098075a
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Showing 2 changed files with 39 additions and 2 deletions.
diff --git a/network/network.go b/network/network.go
@@ -608,6 +608,9 @@ func SubnetInAnyRange(cidrs []*net.IPNet, subnet *net.IPNet) bool {
 	return false
 }
 
+// Export for testing
+var ResolverFunc = net.ResolveIPAddr
+
 // FormatAsCIDR converts the specified IP addresses to
 // a slice of CIDRs.
 func FormatAsCIDR(addresses []string) ([]string, error) {
@@ -616,7 +619,7 @@ func FormatAsCIDR(addresses []string) ([]string, error) {
 		cidr := a
 		// If address is not already a cidr, add a /32 (ipv4) or /128 (ipv6).
 		if _, _, err := net.ParseCIDR(a); err != nil {
-			address, err := net.ResolveIPAddr("ip", a)
+			address, err := ResolverFunc("ip", a)
 			if err != nil {
 				return nil, errors.Trace(err)
 			}

diff --git a/network/network_test.go b/network/network_test.go
@@ -296,7 +296,9 @@ func (s *NetworkSuite) TestQuoteSpaceSet(c *gc.C) {
 	checkQuoteSpaceSet(c, `"", "b"`, "b", "")
 }
 
-type CIDRSuite struct{}
+type CIDRSuite struct {
+	testing.BaseSuite
+}
 
 var _ = gc.Suite(&CIDRSuite{})
 
@@ -381,3 +383,35 @@ func (s *CIDRSuite) TestSubnetInAnyRange(c *gc.C) {
 		c.Assert(result, gc.Equals, t.included)
 	}
 }
+
+// This test shows that FormatAsCIDR will resolve a resolvable hostname to an IP
+// address before formatting as a CIDR.
+func (s *CIDRSuite) TestParseCIDR(c *gc.C) {
+	exampleAddress := "10.10.10.10"
+	exampleHostname := "Hostname"
+	expectedCIDR := "10.10.10.10/32"
+	testAddresses := []struct {
+		address string
+		cidr    string
+	}{{
+		address: exampleAddress,
+		cidr:    expectedCIDR,
+	}, {
+		address: exampleHostname,
+		cidr:    expectedCIDR,
+	}}
+
+	s.PatchValue(&network.ResolverFunc, func(string, hostname string) (*net.IPAddr, error) {
+		return &net.IPAddr{IP: net.ParseIP(exampleAddress)}, nil
+	})
+
+	for _, testAddress := range testAddresses {
+		actualCIDRs, err := network.FormatAsCIDR([]string{testAddress.address})
+		c.Assert(err, jc.ErrorIsNil)
+		if len(actualCIDRs) <= 0 {
+			c.Fail()
+		}
+		actualCIDR := actualCIDRs[0]
+		c.Assert(actualCIDR, gc.Equals, expectedCIDR)
+	}
+}