Add a global fix for anything that involves GetHashPrefixAndSuffix

We tackled this previously with commit
6f78542637b80671cf3153dad8e15ce54dedbb39, but that fix did not
go far enough. Other modules invoke ./hummingbird, so their tests
need the same faking that makeReplicator() needs.

Note that we have 2 kinds of tests: the one that tests the
GetHashPrefixAndSuffix itself and the rest, which uses the
GetHashPrefixAndSuffix in the process of testing something else.
We create a test file for the former and fake everything without
any files for the latter.

Change-Id: Id87cfa6f5271111ae194316de170c6707ba6f23c

go/hummingbird/utils.go

@@ -489,7 +489,11 @@ var configLocations = []string{"/etc/hummingbird/hummingbird.conf", "/etc/swift/
 // GetHashPrefixAndSuffix retrieves the hash path prefix and suffix from
 // the correct configs based on the environments setup. The suffix cannot
 // be nil
-func GetHashPrefixAndSuffix() (prefix string, suffix string, err error) {
+type getHashPrefixAndSuffixFunc func() (pfx string, sfx string, err error)
+
+var GetHashPrefixAndSuffix getHashPrefixAndSuffixFunc = normalGetHashPrefixAndSuffix
+
+func normalGetHashPrefixAndSuffix() (prefix string, suffix string, err error) {
 	for _, loc := range configLocations {
 		if conf, e := LoadConfig(loc); e == nil {
 			var ok bool

go/hummingbird/utils_test.go

@@ -273,14 +273,24 @@ func TestReadDirNames(t *testing.T) {
 	assert.Equal(t, fileNames, []string{"X", "Y", "Z"})
 }
 
-func TestGetHashPrefixAndSuffix(t *testing.T) {
+func fakeHashPrefixAndSuffix() (filename string, err error) {
 	var config_source []byte = []byte(
 		"[swift-hash]\n" +
 			"swift_hash_path_suffix = 983abc1de3ff4258\n")
-	tempFile, _ := ioutil.TempFile("", "swift.conf-")
-	defer os.RemoveAll(tempFile.Name())
+	tempFile, err := ioutil.TempFile("", "swift.conf-")
+	if err != nil {
+		return "", err
+	}
 	ioutil.WriteFile(tempFile.Name(), config_source, 0600)
 	configLocations = []string{tempFile.Name()}
+	return tempFile.Name(), nil
+}
+
+func TestGetHashPrefixAndSuffix(t *testing.T) {
+	swift_conf_name, err := fakeHashPrefixAndSuffix()
+	assert.Nil(t, err)
+	defer os.Remove(swift_conf_name)
+
 	_, suffix, err := GetHashPrefixAndSuffix()
 	assert.Nil(t, err, "Error getting hash path prefix or suffix")
 

go/objectserver/_test.go

@@ -0,0 +1,18 @@
+//  Copyright (c) 2016 Red Hat, Inc.
+
+package objectserver
+
+import (
+	"os"
+
+	"github.com/openstack/swift/go/hummingbird"
+)
+
+func testGetHashPrefixAndSuffix() (pfx string, sfx string, err error) {
+	return "", "983abc1de3ff4258", nil
+}
+
+func TestMain(m *testing.M) {
+	hummingbird.GetHashPrefixAndSuffix = testGetHashPrefixAndSuffix
+	os.Exit(m.Run())
+}