Address PR comments

proxy/common_test.go

@@ -4,6 +4,8 @@ import (
 	"reflect"
 	"regexp"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestFindStringNamedSubmatch(t *testing.T) {
@@ -13,7 +15,5 @@ func TestFindStringNamedSubmatch(t *testing.T) {
 		"barGroup": "bar",
 	}
 	namedSubmatches := findStringNamedSubmatch(re, "prefix foobar suffix")
-	if !reflect.DeepEqual(namedSubmatches, expectedResult) {
-		t.Error("Unexpected result", namedSubmatches)
-	}
+	require.True(t, reflect.DeepEqual(namedSubmatches, expectedResult), "Unexpected namedSubmatches: %s", namedSubmatches)
 }

proxy/proxy.go

@@ -2,7 +2,6 @@ package proxy
 
 import (
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"net"
 	"net/http"
@@ -139,8 +138,8 @@ func unescapeBackSlashes(src string) string {
 func parseHostname(hostname string) (*regexp.Regexp, string, error) {
 	namedSubmatches := findStringNamedSubmatch(substitutionRegexp, hostname)
 	if len(namedSubmatches) < 1 {
-		errStr := fmt.Sprintf("Incorrect hostname expression: %s", hostname)
-		return nil, "", errors.New(errStr)
+		err := fmt.Errorf("Incorrect hostname expression: %s", hostname)
+		return nil, "", err
 	}
 
 	escapedPattern := namedSubmatches[substitutionPatternName]
@@ -150,8 +149,8 @@ func parseHostname(hostname string) (*regexp.Regexp, string, error) {
 
 	patternRegexp, err := regexp.Compile(unescapedPattern)
 	if err != nil {
-		errStr := fmt.Sprintf("Incorrect hostname pattern '%s': %s", escapedPattern, err.Error())
-		return nil, "", errors.New(errStr)
+		err := fmt.Errorf("Incorrect hostname pattern '%s': %s", escapedPattern, err.Error())
+		return nil, "", err
 	}
 
 	return patternRegexp, unescapedReplacement, nil

proxy/proxy_test.go

@@ -2,23 +2,19 @@ package proxy
 
 import (
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestParseHostname(t *testing.T) {
 	hostnameExpr := `/aws-[0-9]+-(.*)/my-app-$1/`
 
 	patternRegexp, replacementStr, err := parseHostname(hostnameExpr)
-	if err != nil {
-		t.Error("Unexpected error", err)
-	}
-	if replacementStr != "my-app-$1" {
-		t.Error("Unexpected replacement string", replacementStr)
-	}
+	require.Nil(t, err, "Unexpected error")
+	require.Equal(t, "my-app-$1", replacementStr, "Unexpected replacement string")
 
 	hostname := patternRegexp.ReplaceAllString("aws-17651276812-name", replacementStr)
-	if hostname != "my-app-name" {
-		t.Error("Unexpected replacement hostname", hostname)
-	}
+	require.Equal(t, "my-app-name", hostname, "Unexpected replacement hostname")
 }
 
 func TestParseWrongHostname(t *testing.T) {
@@ -34,26 +30,17 @@ func TestParseWrongHostname(t *testing.T) {
 
 	for _, hostnameExpr := range wrongHostnameExprs {
 		_, _, err := parseHostname(hostnameExpr)
-		if err == nil {
-			t.Error("Should not succesully parse wrong hostname expression", hostnameExpr)
-		}
+		require.Error(t, err, "Should not parse wrong hostname expression %s", hostnameExpr)
 	}
 }
 
 func TestEscapedHostname(t *testing.T) {
 	hostnameExpr := `/aws\/[0-9]+\/(.*)/my\/app\/$1/`
 
 	patternRegexp, replacementStr, err := parseHostname(hostnameExpr)
-	if err != nil {
-		t.Error("Unexpected error", err)
-	}
-	if replacementStr != "my/app/$1" {
-		t.Error("Unexpected replacement string", replacementStr)
-	}
+	require.Nil(t, err, "Unexpected error", err)
+	require.Equal(t, "my/app/$1", replacementStr, "Unexpected replacement string")
 
 	hostname := patternRegexp.ReplaceAllString("aws/17651276812/name", replacementStr)
-	if hostname != "my/app/name" {
-		t.Error("Unexpected replacement hostname", hostname)
-	}
-
+	require.Equal(t, "my/app/name", hostname, "Unexpected replacement hostname", hostname)
 }

site/proxy.md

@@ -135,10 +135,9 @@ for registration. However, there are situations in which the final container
 name is out of the user's control (e.g. when using Docker orchestrators which
 append control/namespacing identifiers to the original container names).
 
-For those situations, the proxy provides a
-`--hostname=/containerNamePattern/hostnameReplacement/` flag, where
-`/containerNamePattern/hostnameReplacement/` is a regular expression
-substitution command.
+For those situations, the proxy provides a `--hostname=/regexp/replacement/`
+flag, where `/regexp/replacement/` is a regular expression substitution command
+which will be applied to the container name before passing it over to weaveDNS.
 
 For instance, if we launch the proxy using `--hostname='/^aws-[0-9]+-(.*)$/my-app-$1/'`
 

weave

@@ -36,7 +36,8 @@ weave launch-router [--password <password>] [--nickname <nickname>]
                       [--no-discovery] [--init-peer-count <count>] <peer> ...
 weave launch-dns    [<addr>]
 weave launch-proxy  [-H <endpoint>] [--with-dns | --without-dns]
-                      [--no-default-ipalloc] [--no-rewrite-hosts] [--hostname]
+                      [--no-default-ipalloc] [--no-rewrite-hosts]
+                      [--hostname </regexp/replacement/>]
 weave connect       [--replace] [<peer> ...]
 weave forget        <peer> ...
 weave run           [--with-dns | --without-dns] [<addr> ...]