test: Remove dependency on wget

This patch removes the dependency on wget for fetching content over
http, which was used in one of the tests to do some checking on debug
and metric pages, as well as loop detection.

Instead of wget, we now use a small built-in utility called fexp.

test/util/fexp.go

@@ -0,0 +1,195 @@
+// Fetch an URL, and check if the response matches what we expect.
+//
+// Useful for testing HTTP(s) servers.
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+var exitCode int
+
+func main() {
+	if len(os.Args) < 2 {
+		fatalf("Usage: fexp <URL> <options>\n")
+	}
+
+	// The first arg is the URL, and then we shift.
+	url := os.Args[1]
+	os.Args = append([]string{os.Args[0]}, os.Args[2:]...)
+
+	var (
+		body = flag.String("body", "",
+			"expect body with these exact contents")
+		bodyRE = flag.String("bodyre", "",
+			"expect body matching these contents (regexp match)")
+		bodyNotRE = flag.String("bodynotre", "",
+			"expect body NOT matching these contents (regexp match)")
+		redir = flag.String("redir", "",
+			"expect a redirect to this URL")
+		status = flag.Int("status", 200,
+			"expect this status code")
+		verbose = flag.Bool("v", false,
+			"enable verbose output")
+		save = flag.String("save", "",
+			"save body to this file")
+		method = flag.String("method", "GET",
+			"request method to use")
+		hdrRE = flag.String("hdrre", "",
+			"expect a header matching these contents (regexp match)")
+		caCert = flag.String("cacert", "",
+			"file to read CA cert from")
+	)
+	flag.Parse()
+
+	client := &http.Client{
+		CheckRedirect: noRedirect,
+		Transport:     mkTransport(*caCert),
+	}
+
+	req, err := http.NewRequest(*method, url, nil)
+	if err != nil {
+		fatalf("error building request: %q", err)
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		fatalf("error getting %q: %v\n", url, err)
+	}
+	defer resp.Body.Close()
+	rbody, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		errorf("error reading body: %v\n", err)
+	}
+
+	if *save != "" {
+		err = ioutil.WriteFile(*save, rbody, 0664)
+		if err != nil {
+			errorf("error writing body to file %q: %v\n", *save, err)
+		}
+	}
+
+	if *verbose {
+		fmt.Printf("Request: %s\n", url)
+		fmt.Printf("Response:\n")
+		fmt.Printf("  %v  %v\n", resp.Proto, resp.Status)
+		ks := []string{}
+		for k := range resp.Header {
+			ks = append(ks, k)
+		}
+		sort.Strings(ks)
+		for _, k := range ks {
+			fmt.Printf("  %v: %s\n", k,
+				strings.Join(resp.Header[k], ", "))
+		}
+		fmt.Printf("\n")
+	}
+
+	if resp.StatusCode != *status {
+		errorf("status is not %d: %q\n", *status, resp.Status)
+	}
+
+	if *body != "" {
+		// Unescape the body to allow control characters more easily.
+		*body, _ = strconv.Unquote("\"" + *body + "\"")
+		if string(rbody) != *body {
+			errorf("unexpected body: %q\n", rbody)
+		}
+	}
+
+	if *bodyRE != "" {
+		matched, err := regexp.Match(*bodyRE, rbody)
+		if err != nil {
+			errorf("regexp error: %q\n", err)
+		}
+		if !matched {
+			errorf("body did not match regexp: %q\n", rbody)
+		}
+	}
+
+	if *bodyNotRE != "" {
+		matched, err := regexp.Match(*bodyNotRE, rbody)
+		if err != nil {
+			errorf("regexp error: %q\n", err)
+		}
+		if matched {
+			errorf("body matched regexp: %q\n", rbody)
+		}
+	}
+
+	if *redir != "" {
+		if loc := resp.Header.Get("Location"); loc != *redir {
+			errorf("unexpected redir location: %q\n", loc)
+		}
+	}
+
+	if *hdrRE != "" {
+		match := false
+	outer:
+		for k, vs := range resp.Header {
+			for _, v := range vs {
+				hdr := fmt.Sprintf("%s: %s", k, v)
+				matched, err := regexp.MatchString(*hdrRE, hdr)
+				if err != nil {
+					errorf("regexp error: %q\n", err)
+				}
+				if matched {
+					match = true
+					break outer
+				}
+			}
+		}
+
+		if !match {
+			errorf("header did not match: %v\n", resp.Header)
+		}
+	}
+
+	os.Exit(exitCode)
+}
+
+func noRedirect(req *http.Request, via []*http.Request) error {
+	return http.ErrUseLastResponse
+}
+
+func mkTransport(caCert string) http.RoundTripper {
+	if caCert == "" {
+		return nil
+	}
+
+	certs, err := ioutil.ReadFile(caCert)
+	if err != nil {
+		fatalf("error reading CA file %q: %v\n", caCert, err)
+	}
+
+	rootCAs := x509.NewCertPool()
+	if ok := rootCAs.AppendCertsFromPEM(certs); !ok {
+		fatalf("error adding certs to root\n")
+	}
+
+	return &http.Transport{
+		TLSClientConfig: &tls.Config{
+			RootCAs: rootCAs,
+		},
+	}
+}
+
+func fatalf(s string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, s, a...)
+	os.Exit(1)
+}
+
+func errorf(s string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, s, a...)
+	exitCode = 1
+}

test/util/lib.sh

@@ -118,6 +118,11 @@ function minidns_bg() {
 	MINIDNS=$!
 }
 
+function fexp() {
+	( cd ${UTILDIR}; go build fexp.go )
+	${UTILDIR}/fexp "$@"
+}
+
 function success() {
 	echo success
 }