Merge pull request #112414 from pacoxu/kubelet-multi-options

kubelet: append options to pod if there are multi options in /etc/resolv.conf

pkg/kubelet/network/dns/dns.go

@@ -272,7 +272,7 @@ func parseResolvConf(reader io.Reader) (nameservers []string, searches []string,
 			}
 		}
 		if fields[0] == "options" {
-			options = fields[1:]
+			options = appendOptions(options, fields[1:]...)
 		}
 	}
 
@@ -352,6 +352,26 @@ func mergeDNSOptions(existingDNSConfigOptions []string, dnsConfigOptions []v1.Po
 	return options
 }
 
+// appendOptions appends options to the given list, but does not add duplicates.
+// append option will overwrite the previous one either in new line or in the same line.
+func appendOptions(options []string, newOption ...string) []string {
+	var optionMap = make(map[string]string)
+	for _, option := range options {
+		optName := strings.Split(option, ":")[0]
+		optionMap[optName] = option
+	}
+	for _, option := range newOption {
+		optName := strings.Split(option, ":")[0]
+		optionMap[optName] = option
+	}
+
+	options = []string{}
+	for _, v := range optionMap {
+		options = append(options, v)
+	}
+	return options
+}
+
 // appendDNSConfig appends DNS servers, search paths and options given by
 // PodDNSConfig to the existing DNS config. Duplicated entries will be merged.
 // This assumes existingDNSConfig and dnsConfig are not nil.

pkg/kubelet/network/dns/dns_test.go

@@ -91,7 +91,11 @@ func TestParseResolvConf(t *testing.T) {
 		{"#comment\nnameserver 1.2.3.4\n#comment\nsearch foo\ncomment", []string{"1.2.3.4"}, []string{"foo"}, []string{}, false},
 		{"options ", []string{}, []string{}, []string{}, false},
 		{"options ndots:5 attempts:2", []string{}, []string{}, []string{"ndots:5", "attempts:2"}, false},
+		{"options ndots:1 ndots:5 attempts:2", []string{}, []string{}, []string{"ndots:5", "attempts:2"}, false},
+		{"options ndots:1 edns0 attempts:2 single-request-reopen", []string{}, []string{}, []string{"edns0", "attempts:2", "single-request-reopen", "ndots:1"}, false},
 		{"options ndots:1\noptions ndots:5 attempts:3", []string{}, []string{}, []string{"ndots:5", "attempts:3"}, false},
+		{"options ndots:1 timeout:3 timeout:1 attempts:3\noptions ndots:5", []string{}, []string{}, []string{"ndots:5", "timeout:1", "attempts:3"}, false},
+		{"options ndots:1 attempts:3\noptions ndots:1 attempts:3 ndots:5", []string{}, []string{}, []string{"ndots:5", "attempts:3"}, false},
 		{"nameserver 1.2.3.4\nsearch foo\nnameserver 5.6.7.8\nsearch bar\noptions ndots:5 attempts:4", []string{"1.2.3.4", "5.6.7.8"}, []string{"bar"}, []string{"ndots:5", "attempts:4"}, false},
 	}
 	for i, tc := range testCases {
@@ -100,7 +104,7 @@ func TestParseResolvConf(t *testing.T) {
 			require.NoError(t, err)
 			assert.EqualValues(t, tc.nameservers, ns, "test case [%d]: name servers", i)
 			assert.EqualValues(t, tc.searches, srch, "test case [%d] searches", i)
-			assert.EqualValues(t, tc.options, opts, "test case [%d] options", i)
+			assert.EqualValues(t, sets.NewString(tc.options...), sets.NewString(opts...), "test case [%d] options", i)
 		} else {
 			require.Error(t, err, "tc.searches %v", tc.searches)
 		}