Files
mostlymatter/app/slack.go
Agniva De Sarker 021c90f29f MM-30882: Fix read-after-write issue for demoting user (#16911)
* MM-30882: Fix read-after-write issue for demoting user

In (*App).DemoteUserToGuest, we would demote a user, and then immediately
read it back to do future operations from the user. This reading back
of the user had the effect of sticking the old value into the cache
after which it would never be updated.

There was another issue along with this, which was when the invalidation
message would broadcast across the cluster, it would hit the cache invalidation
problem where an unrelated store call would miss the cache because
it was invalidated, and then again read from replica and stick the old value.

To fix all these, we return the new value directly from the store method
to avoid having the app to read it again.

And we add a map in the localcache layer which tracks invalidations made,
and then switch to use master if it's true.

The core change is fairly limited, but due to changing the store method signatures,
a lot of code needed to be updated to pass "context.Background". Therefore the PR
just "appears" to be big, but the main changes are limited to app/user.go,
sqlstore/user_store.go and user_layer.go

https://mattermost.atlassian.net/browse/MM-30882

```release-note
Fix an issue where demoting a user to guest would not take effect in
an environment with read replicas.
```

* Fix concurrent map access

* Fixing mistakes

* fix tests
2021-02-12 19:04:05 +05:30

100 строки
3.5 KiB
Go

// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.
package app
import (
"bytes"
"context"
"fmt"
"mime/multipart"
"regexp"
"strings"
"github.com/mattermost/mattermost-server/v5/model"
"github.com/mattermost/mattermost-server/v5/services/slackimport"
"github.com/mattermost/mattermost-server/v5/store"
)
func (a *App) SlackImport(fileData multipart.File, fileSize int64, teamID string) (*model.AppError, *bytes.Buffer) {
actions := slackimport.Actions{
UpdateActive: a.UpdateActive,
AddUserToChannel: a.AddUserToChannel,
JoinUserToTeam: a.JoinUserToTeam,
CreateDirectChannel: a.createDirectChannel,
CreateGroupChannel: a.createGroupChannel,
CreateChannel: a.CreateChannel,
DoUploadFile: a.DoUploadFile,
GenerateThumbnailImage: a.generateThumbnailImage,
GeneratePreviewImage: a.generatePreviewImage,
InvalidateAllCaches: func() { a.srv.InvalidateAllCaches() },
MaxPostSize: func() int { return a.srv.MaxPostSize() },
PrepareImage: prepareImage,
}
importer := slackimport.New(a.srv.Store, actions, a.Config())
return importer.SlackImport(fileData, fileSize, teamID)
}
func (a *App) ProcessSlackText(text string) string {
text = expandAnnouncement(text)
text = replaceUserIds(a.Srv().Store.User(), text)
return text
}
// Expand announcements in incoming webhooks from Slack. Those announcements
// can be found in the text attribute, or in the pretext, text, title and value
// attributes of the attachment structure. The Slack attachment structure is
// documented here: https://api.slack.com/docs/attachments
func (a *App) ProcessSlackAttachments(attachments []*model.SlackAttachment) []*model.SlackAttachment {
var nonNilAttachments = model.StringifySlackFieldValue(attachments)
for _, attachment := range attachments {
attachment.Pretext = a.ProcessSlackText(attachment.Pretext)
attachment.Text = a.ProcessSlackText(attachment.Text)
attachment.Title = a.ProcessSlackText(attachment.Title)
for _, field := range attachment.Fields {
if field.Value != nil {
// Ensure the value is set to a string if it is set
field.Value = a.ProcessSlackText(fmt.Sprintf("%v", field.Value))
}
}
}
return nonNilAttachments
}
// To mention @channel or @here via a webhook in Slack, the message should contain
// <!channel> or <!here>, as explained at the bottom of this article:
// https://get.slack.help/hc/en-us/articles/202009646-Making-announcements
func expandAnnouncement(text string) string {
a1 := [3]string{"<!channel>", "<!here>", "<!all>"}
a2 := [3]string{"@channel", "@here", "@all"}
for i, a := range a1 {
text = strings.Replace(text, a, a2[i], -1)
}
return text
}
// Replaces user IDs mentioned like this <@userID> to a normal username (eg. @bob)
// This is required so that Mattermost maintains Slack compatibility
// Refer to: https://api.slack.com/changelog/2017-09-the-one-about-usernames
func replaceUserIds(userStore store.UserStore, text string) string {
rgx, err := regexp.Compile("<@([a-zA-Z0-9]+)>")
if err == nil {
userIDs := make([]string, 0)
matches := rgx.FindAllStringSubmatch(text, -1)
for _, match := range matches {
userIDs = append(userIDs, match[1])
}
if users, err := userStore.GetProfileByIds(context.Background(), userIDs, nil, true); err == nil {
for _, user := range users {
text = strings.Replace(text, "<@"+user.Id+">", "@"+user.Username, -1)
}
}
}
return text
}