Harden URL construction and add IPv6 support

Author: courageJ

kubelet-to-gcm/monitor/controller/client.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 	"strings"
@@ -81,7 +82,7 @@ type Client struct {
 // NewClient generates a client to hit the given controller.
 func NewClient(host string, port uint, client *http.Client) (*Client, error) {
 	// Parse our URL upfront, so we can fail fast.
-	urlStr := fmt.Sprintf("http://%s:%d/metrics", host, port)
+	urlStr := fmt.Sprintf("http://%s/metrics", net.JoinHostPort(host, fmt.Sprint(port)))
 	metricsURL, err := url.Parse(urlStr)
 	if err != nil {
 		return nil, err

kubelet-to-gcm/monitor/controller/client_test.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2017 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package controller
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestNewClient(t *testing.T) {
+	testCases := []struct {
+		name        string
+		host        string
+		port        uint
+		expectedURL string
+	}{
+		{
+			name:        "IPv4",
+			host:        "127.0.0.1",
+			port:        10250,
+			expectedURL: "http://127.0.0.1:10250/metrics",
+		},
+		{
+			name:        "IPv6",
+			host:        "2001:db8::1",
+			port:        10250,
+			expectedURL: "http://[2001:db8::1]:10250/metrics",
+		},
+		{
+			name:        "Hostname",
+			host:        "localhost",
+			port:        8080,
+			expectedURL: "http://localhost:8080/metrics",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			c, err := NewClient(tc.host, tc.port, http.DefaultClient)
+			if err != nil {
+				t.Fatalf("NewClient failed: %v", err)
+			}
+			if c.metricsURL.String() != tc.expectedURL {
+				t.Errorf("Expected URL %q, got %q", tc.expectedURL, c.metricsURL.String())
+			}
+		})
+	}
+}

kubelet-to-gcm/monitor/kubelet/client.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 
@@ -40,7 +41,7 @@ func NewClient(host string, port uint, client *http.Client, useAuthPort bool) (*
 	if useAuthPort {
 		protocol = "https"
 	}
-	urlStr := fmt.Sprintf("%s://%s:%d/stats/summary", protocol, host, port)
+	urlStr := fmt.Sprintf("%s://%s/stats/summary", protocol, net.JoinHostPort(host, fmt.Sprint(port)))
 	summaryURL, err := url.Parse(urlStr)
 	if err != nil {
 		return nil, err

kubelet-to-gcm/monitor/kubelet/client_test.go

@@ -0,0 +1,73 @@
+/*
+Copyright 2017 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubelet
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestNewClient(t *testing.T) {
+	testCases := []struct {
+		name        string
+		host        string
+		port        uint
+		useAuthPort bool
+		expectedURL string
+	}{
+		{
+			name:        "IPv4 HTTP",
+			host:        "127.0.0.1",
+			port:        10255,
+			useAuthPort: false,
+			expectedURL: "http://127.0.0.1:10255/stats/summary",
+		},
+		{
+			name:        "IPv4 HTTPS",
+			host:        "127.0.0.1",
+			port:        10250,
+			useAuthPort: true,
+			expectedURL: "https://127.0.0.1:10250/stats/summary",
+		},
+		{
+			name:        "IPv6 HTTP",
+			host:        "2001:db8::1",
+			port:        10255,
+			useAuthPort: false,
+			expectedURL: "http://[2001:db8::1]:10255/stats/summary",
+		},
+		{
+			name:        "IPv6 HTTPS",
+			host:        "2001:db8::1",
+			port:        10250,
+			useAuthPort: true,
+			expectedURL: "https://[2001:db8::1]:10250/stats/summary",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			c, err := NewClient(tc.host, tc.port, http.DefaultClient, tc.useAuthPort)
+			if err != nil {
+				t.Fatalf("NewClient failed: %v", err)
+			}
+			if c.summaryURL.String() != tc.expectedURL {
+				t.Errorf("Expected URL %q, got %q", tc.expectedURL, c.summaryURL.String())
+			}
+		})
+	}
+}