pkg/utils: use name+id for hash and extend tests

diff --git a/utils/utils.go b/utils/utils.go
index eaf48d0..a07ccfa 100644 (file)
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -5,16 +5,15 @@ import (
        "fmt"
 )
 
-// 29 - len('CNI') - 2*len('-')
-const maxNameLen = 16
+const MaxChainLength = 29 - len("CNI-")
 
 // Generates a chain name to be used with iptables.
 // Ensures that the generated name is less than
 // 29 chars in length
 func FormatChainName(name string, id string) string {
-       h := sha512.Sum512([]byte(id))
-       if len(name) > maxNameLen {
-               return fmt.Sprintf("CNI-%s-%x", name[:len(name)-maxNameLen], h[:8])
+       chain := fmt.Sprintf("%x", sha512.Sum512([]byte(name+id)))
+       if len(chain) > MaxChainLength {
+               chain = chain[:MaxChainLength]
        }
-       return fmt.Sprintf("CNI-%s-%x", name, h[:8])
+       return fmt.Sprintf("CNI-%s", chain)
 }

diff --git a/utils/utils_test.go b/utils/utils_test.go
index e9b9f9b..05fde8a 100644 (file)
--- a/utils/utils_test.go
+++ b/utils/utils_test.go
@@ -6,13 +6,34 @@ import (
 )
 
 var _ = Describe("Utils", func() {
-       It("should format a short name", func() {
+       It("must format a short name", func() {
                chain := FormatChainName("test", "1234")
-               Expect(chain).To(Equal("CNI-test-d404559f602eab6f"))
+               Expect(len(chain) == 29).To(Equal(true))
+               Expect(chain).To(Equal("CNI-2bbe0c48b91a7d1b8a6753a8b"))
        })
 
-       It("should truncate a long name", func() {
+       It("must truncate a long name", func() {
                chain := FormatChainName("testalongnamethatdoesnotmakesense", "1234")
-               Expect(chain).To(Equal("CNI-testalongnamethat-d404559f602eab6f"))
+               Expect(len(chain) == 29).To(Equal(true))
+               Expect(chain).To(Equal("CNI-374f33fe84ab0ed84dcdebe38"))
        })
+
+       It("must be predictable", func() {
+               chain1 := FormatChainName("testalongnamethatdoesnotmakesense", "1234")
+               chain2 := FormatChainName("testalongnamethatdoesnotmakesense", "1234")
+               Expect(len(chain1) == 29).To(Equal(true))
+               Expect(len(chain2) == 29).To(Equal(true))
+               Expect(chain1).To(Equal(chain2))
+       })
+
+       It("must change when a character changes", func() {
+               chain1 := FormatChainName("testalongnamethatdoesnotmakesense", "1234")
+               chain2 := FormatChainName("testalongnamethatdoesnotmakesense", "1235")
+               Expect(len(chain1) == 29).To(Equal(true))
+               Expect(len(chain2) == 29).To(Equal(true))
+               Expect(chain1).To(Equal("CNI-374f33fe84ab0ed84dcdebe38"))
+               Expect(chain2).NotTo(Equal("CNI-374f33fe84ab0ed84dcdebe38"))
+               Expect(chain1).NotTo(Equal(chain2))
+       })
+
 })