Unable to reach Postgresql host or socket while not on default 5432 port

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Nextcloud doesn't take into account the port setup when constructing the full full postgresql socket path. It always uses 5432, whatever the dbport setup is in config.php.
Thus it is not possible to connect through socket way when Postgresql is not running on the default 5432 port.

Steps to reproduce

1. in config.php set 'dbhost' to '/var/run/postgresql' (which is the debian root path of postgresql socket)
2. and set 'dbport' to '1234' for instance
3. try to load any nextcloud page
4. check into the log for the error and the socket path shown

Expected behavior

Normally, the connection socket should be /var/run/postgresql/.s.PSQL.1234, while it is stuck to /var/run/postgresql/s.PSQL.5432

I think a better way for setup would be to fill the full socket path into dbhost parameter (eg /var/run/postgresql/.s.PSQL.1234) rather than splitting the socket config, as the postgresql config could even use another schema and/or path for the socket full path (for instance in the case when several parallel sockets are used for isolation).

Installation method

Community Web installer on a VPS or web space

Nextcloud Server version

29

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

Fresh Nextcloud Server install

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "***REMOVED SENSITIVE VALUE***"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "29.0.0.19",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true
    }
}

List of activated Apps

Enabled:
  - activity: 2.21.1
  - calendar: 4.7.4
  - circles: 29.0.0-dev
  - cloud_federation_api: 1.12.0
  - comments: 1.19.0
  - contacts: 6.0.0
  - contactsinteraction: 1.10.0
  - dashboard: 7.9.0
  - dav: 1.30.1
  - federatedfilesharing: 1.19.0
  - federation: 1.19.0
  - files: 2.1.0
  - files_downloadlimit: 2.0.0
  - files_pdfviewer: 2.10.0
  - files_reminders: 1.2.0
  - files_sharing: 1.21.0
  - files_trashbin: 1.19.0
  - files_versions: 1.22.0
  - firstrunwizard: 2.18.0
  - logreader: 2.14.0
  - lookup_server_connector: 1.17.0
  - mail: 3.6.1
  - nextcloud_announcements: 1.18.0
  - notes: 4.10.0
  - notifications: 2.17.0
  - oauth2: 1.17.0
  - password_policy: 1.19.0
  - photos: 2.5.0
  - privacy: 1.13.0
  - provisioning_api: 1.19.0
  - recommendations: 2.1.0
  - related_resources: 1.4.0
  - richdocuments: 8.4.2
  - serverinfo: 1.19.0
  - settings: 1.12.0
  - sharebymail: 1.19.0
  - spreed: 19.0.1
  - support: 1.12.0
  - survey_client: 1.17.0
  - systemtags: 1.19.0
  - text: 3.10.0
  - theming: 2.4.0
  - twofactor_backupcodes: 1.18.0
  - updatenotification: 1.19.1
  - user_status: 1.9.0
  - viewer: 2.3.0
  - weather_status: 1.9.0
  - workflowengine: 2.11.0
Disabled:
  - admin_audit: 1.19.0
  - bruteforcesettings: 2.9.0
  - encryption: 2.17.0
  - files_external: 1.21.0
  - suspicious_login: 7.0.0
  - twofactor_totp: 11.0.0-dev
  - user_ldap: 1.20.0

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start with the database settings in config.php and reproduce the PostgreSQL connection using dbhost=/var/run/postgresql and dbport=1234. Trace where the socket path is constructed and verify the completed connection uses the configured port rather than 5432; done when the reported socket path and connection use .s.PSQL.1234.