From ca91b5eddd7c00c76b3f9cff425ec4e15c8718f7 Mon Sep 17 00:00:00 2001 From: Mike Bland Date: Sat, 9 May 2015 19:31:38 -0400 Subject: [PATCH] Reload authenticated-emails-file upon update This change extracts the UserMap class from NewValidator() so that its LoadAuthenticatedEmailsFile() method can be called concurrently. This method is called by a goroutine containing a fsnotify.Watcher watching the authenticated emails file. Watching isn't forever aborted when the authenticated emails file disappears. The goroutine will call os.Stat() up to twenty times a second if the file is persistently missing, but that's the pathological case, not the common one. The common case is that some editors (including Vim) will perform a rename-and-replace when updating a file, triggering fsnotify.Rename events, and the file will temporarily disappear. This watcher goroutine handles that case. Also, on some platforms (notably Arch Linux), a remove will be preceded by a fsnotify.Chmod, causing a race between the upcoming fsnotify.Remove and the call to UserMap.LoadAuthenticatedEmailsFile(). Hence, we treat fsnotify.Chmod the same as fsnotify.Remove and fsnotify.Rename. There's no significant penalty to re-adding a file to the watcher. Also contains the following small changes from the summary of commits below: - Minor optimization of email domain search - Fixed api_test.go on Windows - Add deferred File.Close() calls where needed - Log error and return if emails file doesn't parse These are the original commits from #89 squashed into this one: 0c6f2b6 Refactor validator_test to prepare for more tests e0c792b Add more test cases to validator_test a9a9d93 Minor optimization of email domain search b763ea5 Extract LoadAuthenticatedEmailsFile() 8cdaf7f Introduce synchronized UserMap type 1b84eef Add UserMap methods, locking af15dcf Reload authenticated-emails-file upon update 6d95548 Make UserMap operations lock-free Per: - http://stackoverflow.com/questions/21447463/is-assigning-a-pointer-atomic-in-golang - https://groups.google.com/forum/#!msg/golang-nuts/ueSvaEKgyLY/ZW_74IC4PekJ 75755d5 Fix tests on Windows d0eab2e Ignore email file watcher Chmod events 0b9798b Fix watcher on Ubuntu 12.04 3a8251a WaitForReplacement() to retry emails file watch a57fd29 Add deferred File.Close() calls where needed Because correctness: Don't leak file handles anywhere, and prepare for future panics and early returns. 52ed3fd Log error and return if emails file doesn't parse 40100d4 Add gopkg.in/fsnotify.v1 dependency to Godeps file 17dfbbc Avoid a race when Remove is preceded by Chmod --- Godeps | 1 + api/api_test.go | 4 +- htpasswd.go | 1 + validator.go | 75 +++++++++++++++++----- validator_test.go | 114 ++++++++++++++++++++++++++++++--- validator_watcher_copy_test.go | 50 +++++++++++++++ validator_watcher_test.go | 105 ++++++++++++++++++++++++++++++ watcher.go | 64 ++++++++++++++++++ watcher_unsupported.go | 13 ++++ 9 files changed, 398 insertions(+), 29 deletions(-) create mode 100644 validator_watcher_copy_test.go create mode 100644 validator_watcher_test.go create mode 100644 watcher.go create mode 100644 watcher_unsupported.go diff --git a/Godeps b/Godeps index 41bef4c..6a77c0f 100644 --- a/Godeps +++ b/Godeps @@ -2,3 +2,4 @@ github.com/BurntSushi/toml 3883ac1ce943878302255f538fce319d23226223 github.com/bitly/go-simplejson 3378bdcb5cebedcbf8b5750edee28010f128fe24 github.com/mreiferson/go-options ee94b57f2fbf116075426f853e5abbcdfeca8b3d github.com/bmizerany/assert e17e99893cb6509f428e1728281c2ad60a6b31e3 +gopkg.in/fsnotify.v1 v1.2.0 diff --git a/api/api_test.go b/api/api_test.go index 2494131..8327a28 100644 --- a/api/api_test.go +++ b/api/api_test.go @@ -40,8 +40,8 @@ func TestRequestFailure(t *testing.T) { resp, err := Request(req) assert.Equal(t, (*simplejson.Json)(nil), resp) assert.NotEqual(t, nil, err) - if !strings.HasSuffix(err.Error(), "connection refused") { - t.Error("expected error when a connection fails") + if !strings.Contains(err.Error(), "refused") { + t.Error("expected error when a connection fails: ", err) } } diff --git a/htpasswd.go b/htpasswd.go index 5988c7c..6fd888e 100644 --- a/htpasswd.go +++ b/htpasswd.go @@ -21,6 +21,7 @@ func NewHtpasswdFromFile(path string) (*HtpasswdFile, error) { if err != nil { return nil, err } + defer r.Close() return NewHtpasswd(r) } diff --git a/validator.go b/validator.go index f85e1d4..8c3e985 100644 --- a/validator.go +++ b/validator.go @@ -6,43 +6,84 @@ import ( "log" "os" "strings" + "sync/atomic" + "unsafe" ) -func NewValidator(domains []string, usersFile string) func(string) bool { - validUsers := make(map[string]bool) +type UserMap struct { + usersFile string + m unsafe.Pointer +} +func NewUserMap(usersFile string, onUpdate func()) *UserMap { + um := &UserMap{usersFile: usersFile} + m := make(map[string]bool) + atomic.StorePointer(&um.m, unsafe.Pointer(&m)) if usersFile != "" { log.Printf("using authenticated emails file %s", usersFile) - r, err := os.Open(usersFile) - if err != nil { - log.Fatalf("failed opening authenticated-emails-file=%q, %s", usersFile, err) - } - csv_reader := csv.NewReader(r) - csv_reader.Comma = ',' - csv_reader.Comment = '#' - csv_reader.TrimLeadingSpace = true - records, err := csv_reader.ReadAll() - for _, r := range records { - validUsers[strings.ToLower(r[0])] = true + started := WatchForUpdates(usersFile, func() { + um.LoadAuthenticatedEmailsFile() + onUpdate() + }) + if started { + log.Printf("watching %s for updates", usersFile) } + um.LoadAuthenticatedEmailsFile() } + return um +} + +func (um *UserMap) IsValid(email string) (result bool) { + m := *(*map[string]bool)(atomic.LoadPointer(&um.m)) + _, result = m[email] + return +} + +func (um *UserMap) LoadAuthenticatedEmailsFile() { + r, err := os.Open(um.usersFile) + if err != nil { + log.Fatalf("failed opening authenticated-emails-file=%q, %s", um.usersFile, err) + } + defer r.Close() + csv_reader := csv.NewReader(r) + csv_reader.Comma = ',' + csv_reader.Comment = '#' + csv_reader.TrimLeadingSpace = true + records, err := csv_reader.ReadAll() + if err != nil { + log.Printf("error reading authenticated-emails-file=%q, %s", um.usersFile, err) + return + } + updated := make(map[string]bool) + for _, r := range records { + updated[strings.ToLower(r[0])] = true + } + atomic.StorePointer(&um.m, unsafe.Pointer(&updated)) +} + +func newValidatorImpl(domains []string, usersFile string, + onUpdate func()) func(string) bool { + validUsers := NewUserMap(usersFile, onUpdate) for i, domain := range domains { - domains[i] = strings.ToLower(domain) + domains[i] = fmt.Sprintf("@%s", strings.ToLower(domain)) } validator := func(email string) bool { email = strings.ToLower(email) valid := false for _, domain := range domains { - emailSuffix := fmt.Sprintf("@%s", domain) - valid = valid || strings.HasSuffix(email, emailSuffix) + valid = valid || strings.HasSuffix(email, domain) } if !valid { - _, valid = validUsers[email] + valid = validUsers.IsValid(email) } log.Printf("validating: is %s valid? %v", email, valid) return valid } return validator } + +func NewValidator(domains []string, usersFile string) func(string) bool { + return newValidatorImpl(domains, usersFile, func() {}) +} diff --git a/validator_test.go b/validator_test.go index 3c223bd..0912b36 100644 --- a/validator_test.go +++ b/validator_test.go @@ -7,23 +7,117 @@ import ( "testing" ) -func TestValidatorComparisonsAreCaseInsensitive(t *testing.T) { - auth_email_file, err := ioutil.TempFile("", "test_auth_emails_") +type ValidatorTest struct { + auth_email_file *os.File +} + +func NewValidatorTest(t *testing.T) *ValidatorTest { + vt := &ValidatorTest{} + var err error + vt.auth_email_file, err = ioutil.TempFile("", "test_auth_emails_") if err != nil { t.Fatal("failed to create temp file: " + err.Error()) } - defer os.Remove(auth_email_file.Name()) + return vt +} - auth_email_file.WriteString( - strings.Join([]string{"Foo.Bar@Example.Com"}, "\n")) - err = auth_email_file.Close() - if err != nil { - t.Fatal("failed to close temp file " + auth_email_file.Name() + - ": " + err.Error()) +func (vt *ValidatorTest) TearDown() { + os.Remove(vt.auth_email_file.Name()) +} + +// This will close vt.auth_email_file. +func (vt *ValidatorTest) WriteEmails(t *testing.T, emails []string) { + defer vt.auth_email_file.Close() + vt.auth_email_file.WriteString(strings.Join(emails, "\n")) + if err := vt.auth_email_file.Close(); err != nil { + t.Fatal("failed to close temp file " + + vt.auth_email_file.Name() + ": " + err.Error()) } +} +func TestValidatorEmpty(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string(nil)) + domains := []string(nil) + validator := NewValidator(domains, vt.auth_email_file.Name()) + + if validator("foo.bar@example.com") { + t.Error("nothing should validate when the email and " + + "domain lists are empty") + } +} + +func TestValidatorSingleEmail(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{"foo.bar@example.com"}) + domains := []string(nil) + validator := NewValidator(domains, vt.auth_email_file.Name()) + + if !validator("foo.bar@example.com") { + t.Error("email should validate") + } + if validator("baz.quux@example.com") { + t.Error("email from same domain but not in list " + + "should not validate when domain list is empty") + } +} + +func TestValidatorSingleDomain(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string(nil)) + domains := []string{"example.com"} + validator := NewValidator(domains, vt.auth_email_file.Name()) + + if !validator("foo.bar@example.com") { + t.Error("email should validate") + } + if !validator("baz.quux@example.com") { + t.Error("email from same domain should validate") + } +} + +func TestValidatorMultipleEmailsMultipleDomains(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{ + "xyzzy@example.com", + "plugh@example.com", + }) + domains := []string{"example0.com", "example1.com"} + validator := NewValidator(domains, vt.auth_email_file.Name()) + + if !validator("foo.bar@example0.com") { + t.Error("email from first domain should validate") + } + if !validator("baz.quux@example1.com") { + t.Error("email from second domain should validate") + } + if !validator("xyzzy@example.com") { + t.Error("first email in list should validate") + } + if !validator("plugh@example.com") { + t.Error("second email in list should validate") + } + if validator("xyzzy.plugh@example.com") { + t.Error("email not in list that matches no domains " + + "should not validate") + } +} + +func TestValidatorComparisonsAreCaseInsensitive(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{"Foo.Bar@Example.Com"}) domains := []string{"Frobozz.Com"} - validator := NewValidator(domains, auth_email_file.Name()) + validator := NewValidator(domains, vt.auth_email_file.Name()) if !validator("foo.bar@example.com") { t.Error("loaded email addresses are not lower-cased") diff --git a/validator_watcher_copy_test.go b/validator_watcher_copy_test.go new file mode 100644 index 0000000..35bed3a --- /dev/null +++ b/validator_watcher_copy_test.go @@ -0,0 +1,50 @@ +// +build go1.3 +// +build !plan9,!solaris,!windows + +// Turns out you can't copy over an existing file on Windows. + +package main + +import ( + "io/ioutil" + "os" + "testing" +) + +func (vt *ValidatorTest) UpdateEmailFileViaCopyingOver( + t *testing.T, emails []string) { + orig_file := vt.auth_email_file + var err error + vt.auth_email_file, err = ioutil.TempFile("", "test_auth_emails_") + if err != nil { + t.Fatal("failed to create temp file for copy: " + err.Error()) + } + vt.WriteEmails(t, emails) + err = os.Rename(vt.auth_email_file.Name(), orig_file.Name()) + if err != nil { + t.Fatal("failed to copy over temp file: " + err.Error()) + } + vt.auth_email_file = orig_file +} + +func TestValidatorOverwriteEmailListViaCopyingOver(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{"xyzzy@example.com"}) + domains := []string(nil) + updated := make(chan bool) + validator := newValidatorImpl(domains, vt.auth_email_file.Name(), + func() { updated <- true }) + + if !validator("xyzzy@example.com") { + t.Error("email in list should validate") + } + + vt.UpdateEmailFileViaCopyingOver(t, []string{"plugh@example.com"}) + <-updated + + if validator("xyzzy@example.com") { + t.Error("email removed from list should not validate") + } +} diff --git a/validator_watcher_test.go b/validator_watcher_test.go new file mode 100644 index 0000000..691644f --- /dev/null +++ b/validator_watcher_test.go @@ -0,0 +1,105 @@ +// +build go1.3 +// +build !plan9,!solaris + +package main + +import ( + "io/ioutil" + "os" + "testing" +) + +func (vt *ValidatorTest) UpdateEmailFile(t *testing.T, emails []string) { + var err error + vt.auth_email_file, err = os.OpenFile( + vt.auth_email_file.Name(), os.O_WRONLY|os.O_CREATE, 0600) + if err != nil { + t.Fatal("failed to re-open temp file for updates") + } + vt.WriteEmails(t, emails) +} + +func (vt *ValidatorTest) UpdateEmailFileViaRenameAndReplace( + t *testing.T, emails []string) { + orig_file := vt.auth_email_file + var err error + vt.auth_email_file, err = ioutil.TempFile("", "test_auth_emails_") + if err != nil { + t.Fatal("failed to create temp file for rename and replace: " + + err.Error()) + } + vt.WriteEmails(t, emails) + + moved_name := orig_file.Name() + "-moved" + err = os.Rename(orig_file.Name(), moved_name) + err = os.Rename(vt.auth_email_file.Name(), orig_file.Name()) + if err != nil { + t.Fatal("failed to rename and replace temp file: " + + err.Error()) + } + vt.auth_email_file = orig_file + os.Remove(moved_name) +} + +func TestValidatorOverwriteEmailListDirectly(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{ + "xyzzy@example.com", + "plugh@example.com", + }) + domains := []string(nil) + updated := make(chan bool) + validator := newValidatorImpl(domains, vt.auth_email_file.Name(), + func() { updated <- true }) + + if !validator("xyzzy@example.com") { + t.Error("first email in list should validate") + } + if !validator("plugh@example.com") { + t.Error("second email in list should validate") + } + if validator("xyzzy.plugh@example.com") { + t.Error("email not in list that matches no domains " + + "should not validate") + } + + vt.UpdateEmailFile(t, []string{ + "xyzzy.plugh@example.com", + "plugh@example.com", + }) + <-updated + + if validator("xyzzy@example.com") { + t.Error("email removed from list should not validate") + } + if !validator("plugh@example.com") { + t.Error("email retained in list should validate") + } + if !validator("xyzzy.plugh@example.com") { + t.Error("email added to list should validate") + } +} + +func TestValidatorOverwriteEmailListViaRenameAndReplace(t *testing.T) { + vt := NewValidatorTest(t) + defer vt.TearDown() + + vt.WriteEmails(t, []string{"xyzzy@example.com"}) + domains := []string(nil) + updated := make(chan bool) + validator := newValidatorImpl(domains, vt.auth_email_file.Name(), + func() { updated <- true }) + + if !validator("xyzzy@example.com") { + t.Error("email in list should validate") + } + + vt.UpdateEmailFileViaRenameAndReplace(t, []string{"plugh@example.com"}) + <-updated + + if validator("xyzzy@example.com") { + t.Error("email removed from list should not validate") + } +} diff --git a/watcher.go b/watcher.go new file mode 100644 index 0000000..32c91f2 --- /dev/null +++ b/watcher.go @@ -0,0 +1,64 @@ +// +build go1.3 +// +build !plan9,!solaris + +package main + +import ( + "log" + "os" + "path/filepath" + "time" + + "gopkg.in/fsnotify.v1" +) + +func WaitForReplacement(event fsnotify.Event, watcher *fsnotify.Watcher) { + const sleep_interval = 50 * time.Millisecond + + // Avoid a race when fsnofity.Remove is preceded by fsnotify.Chmod. + if event.Op&fsnotify.Chmod != 0 { + time.Sleep(sleep_interval) + } + for { + if _, err := os.Stat(event.Name); err == nil { + if err := watcher.Add(event.Name); err == nil { + log.Printf("watching resumed for %s", event.Name) + return + } + } + time.Sleep(sleep_interval) + } +} + +func WatchForUpdates(filename string, action func()) bool { + filename = filepath.Clean(filename) + watcher, err := fsnotify.NewWatcher() + if err != nil { + log.Fatal("failed to create watcher for ", filename, ": ", err) + } + go func() { + defer watcher.Close() + for { + select { + case event := <-watcher.Events: + // On Arch Linux, it appears Chmod events precede Remove events, + // which causes a race between action() and the coming Remove event. + // If the Remove wins, the action() (which calls + // UserMap.LoadAuthenticatedEmailsFile()) crashes when the file + // can't be opened. + if event.Op&(fsnotify.Remove|fsnotify.Rename|fsnotify.Chmod) != 0 { + log.Printf("watching interrupted on event: %s", event) + WaitForReplacement(event, watcher) + } + log.Printf("reloading after event: %s", event) + action() + case err := <-watcher.Errors: + log.Printf("error watching %s: %s", filename, err) + } + } + }() + if err = watcher.Add(filename); err != nil { + log.Fatal("failed to add ", filename, " to watcher: ", err) + } + return true +} diff --git a/watcher_unsupported.go b/watcher_unsupported.go new file mode 100644 index 0000000..d94e11e --- /dev/null +++ b/watcher_unsupported.go @@ -0,0 +1,13 @@ +// +build go1.1 +// +build plan9,solaris + +package main + +import ( + "log" +) + +func WatchForUpdates(filename string, action func()) bool { + log.Printf("file watching not implemented on this platform") + return false +}