Carbonio Docs Editor opens a blank page because nginx proxy temp directory is created with incorrect permissions

Issue Type: [BUG]

Summary: Carbonio Docs Editor opens a blank page because nginx proxy temp directory is created with incorrect permissions

Affected Components: Carbonio Proxy / nginx / Carbonio Docs Editor

Description:

On a Carbonio CE installation, document preview worked correctly, but opening a DOCX file in Edit mode resulted in a completely blank editor window.

All Carbonio Docs-related services were running and reported as active.

The problem was eventually traced to the nginx proxy temporary directory:

/opt/zextras/data/tmp/nginx/proxy

Its ownership and permissions were:

nobody:zextras
mode 0755

With these permissions, the nginx worker handling the request did not have write access to the proxy temporary directory.

As a consequence, nginx could not correctly create/use a proxy temporary file while serving resources required by the Docs Editor. In the browser this manifested itself as the editor JavaScript bundle not being delivered correctly, while document preview continued to work.

This is especially confusing because all Docs services remain active and no obvious error is displayed in the Carbonio web interface.

After correcting the permissions/ownership of the nginx proxy temporary directory so that the nginx worker could write to it, the same document opened normally in the editor.

Server OS:
[insert output of /etc/os-release]

Carbonio Version:
[insert output of: su - zextras -c "zmcontrol -v"]

Current Behavior:

1. Carbonio services are running.

2. DOCX preview works.

3. Clicking Edit opens the Docs Editor.

4. The editor remains blank.

5. Required web resources are not delivered correctly.

6. nginx reports a permission problem related to its proxy temporary directory.

7. /opt/zextras/data/tmp/nginx/proxy has ownership nobody:zextras and mode 0755.

Expected Behavior:

The Carbonio package installation, upgrade scripts, systemd/tmpfiles configuration, or Carbonio permission repair mechanism should always create the nginx temporary directories with ownership and permissions compatible with the actual nginx worker user.

A fresh installation or service restart should never leave:

/opt/zextras/data/tmp/nginx/proxy

in a state where nginx cannot write to it.

Steps to Reproduce:

1. Install/update Carbonio CE normally.

2. Verify that Carbonio Docs services are active.

3. Upload or select a DOCX document.

4. Open the document preview — preview works.

5. Click Edit.

6. Observe a blank editor window.

7. Inspect nginx logs and browser network requests.

8. Check:
   stat -c '%A %a %U:%G %n' /opt/zextras/data/tmp/nginx/proxy

9. Observe:
   nobody:zextras with mode 0755.

10. Correct the directory permissions/ownership so that the nginx worker can write to it.

11. Retry Edit.

12. The document editor now loads successfully.

Workaround:

Manually correct the ownership/permissions of:

/opt/zextras/data/tmp/nginx/proxy

so that the nginx worker process can create proxy temporary files.

Suggested Fix:

Please check the package post-installation scripts, systemd tmpfiles configuration and any Carbonio permission-fixing logic responsible for /opt/zextras/data/tmp/nginx/.

The directory should be automatically created with ownership and mode matching the nginx runtime user, and the correct permissions should survive:

• fresh installation;

• package upgrade;

• Carbonio restart;

• host reboot;

• permission repair procedures.

Impact:

This effectively disables document editing while giving the administrator the impression that the Docs infrastructure is healthy, because all related services remain active and document preview still works.